10 Best Anti-Aging Foods to Eat Every Day

The greatest desire of every woman is to stay young and beautiful as long as possible. We usually try various methods in order to prevent the aging process in our body. Though, our efforts are not always successful. It is necessary to remember that certain things can help you to add years to your life. Firstly, you should lead a healthy lifestyle. For this you need to do regular physical exercises and include wholesome foods into your diet. If you want to stay young and avoid numerous age-related diseases, I recommend you to consume the following anti-aging foods every day. They are extremely beneficial for your health!

1. Fish
The conducted researches have shown that those people who eat a lot of fish almost never suffer from heart disease. For example, the native Inuits of Alaska are not familiar with this health issue because they regularly consume a big amount of fish. This food is known to be rich in omega-3 fats that will stabilize your heart rhythms and protect you against cholesterol buildup in arteries.

2. Olive Oil
Due to the fact that olive oil is high in monounsaturated fats it is one of those foods that are efficient in fighting cancer and heart disease. Everybody knows that people who live in Greece constantly use olive oil for cooking. Scientists’ studies have proven that the consumption of this oil lowers rates of heart diseases among the citizens of this country. By adding olive oil to your dishes you will supply your body with antioxidants and polyphenols which you need to resist different age-related diseases.

3. Chocolate
Cocoa is the main ingredient of chocolate. It has a high concentration of flavanols that are very good for blood vessels. When your blood vessels function well, you’re able to reduce the risk of type 2 diabetes, high blood pressure, dementia and kidney disease. That’s why you can easily enjoy the sweet taste of your favorite chocolate. Just make sure you control your portions, or this dessert will be harmful to your health. Besides chocolate bars, there is a wide range of beverages made of cocoa. By drinking them you’ll have a chance to prevent heart disease.

4. Yogurt
Some years ago Georgia was one of the countries that had the biggest number of centenarians in the world. Yogurt was claimed to be the main secret of their long lives. This dairy product is frequently used in most diets that are so popular nowadays. Perhaps you’ve never heard before but yogurt may slow the aging process. Being full of calcium, this food is extremely effective in preventing osteoporosis. In addition, “good bacteria” that are found in yogurt will strengthen your immune system and improve your overall health.

5. Blueberries
Dietarians state that blueberries may have a fantastic impact on human body. If you include these delicious and wholesome berries into your daily menu you’ll be amazed with the results. According to scientific studies blueberries are considered to increase people’s coordination when they become old. Plus, this food contains compounds that can easily diminish oxidative damage and inflammation. These health problems can lead to deficits in memory and motor function when you are old. So, blueberries are a wonderful choice for healthy aging.

6. Nuts
If you really care about your health and beauty, I would advise you to add nuts to your eating plan. This food is an enormous source of unsaturated fats and it can affect your body in the same way as olive oil does. Recently it has been found out that people who eat nuts live a few years longer than those who refuse from this tasty snack. Such nutrients as vitamins, antioxidants and minerals, make nuts one of the healthiest foods. Today you can find different kinds of nuts that are also a perfect option for vegetarians.

7. Wine
The negative influence of alcohol on our health is undeniable. Some people even don’t guess that when consumed in moderate doses alcohol can be salubrious for them. It should be mentioned that wine is the most preferable alcoholic beverage all over the world. If you drink wine, you will not only enjoy its refined taste but you will protect yourself against numerous diseases as well. Those who drink red wine are less subjected to diabetes, memory loss and heart disease. What is more important, this beverage will slow the process of aging in your body.

8. Carrots
Carrot is another fantastic food that will certainly help you to look younger and you will supply your body with various vitamins and nutrients that are necessary to be healthy. This orange vegetable is a perfect source of alpha- and beta-carotene that are known to boost our immunity and even stave off cancer. Moreover, carrots may be effectively used to care for your skin because carotenoids protect it from UV damage. When summer comes, you should try to add carrots to your diet and don’t forget to apply sunscreen either.

9. Sunflower Seeds
First of all, I’d like to say that most of us give preference to these seeds when looking for yummy snacks. Do you know that this food is very good for your health? We can hardly find any other food that is more packed with vitamin E than sunflower seeds. We all need to consume this vitamin in order to enhance our immune system which becomes weak with age. Nevertheless you have all chances to roll back the years by eating your favorite sunflower seeds.

10. Prunes
Perhaps you are surprised to see prunes on this list, but it has been proven that this food can be even more efficient than fresh fruits when it comes to our health. One of the reasons why prunes are so useful to us is their capacity to remove harmful free radicals from the blood and improve our circulation. Being dried, prunes have a big quantity of good things that have positive effect on our body. As an alternative to prunes you can also eat raisins or figs.

Unfortunately, we can’t stop time and stay young forever. However, we have endless opportunities to add years to our life and to look amazing no matter how old we are. All the above foods will definitely help you to stay healthy and by eating them you’ll be able to avoid various age-related diseases. What methods do you use to prevent the negative effects of aging? Do you eat any other anti-aging foods? What are they?

10 Healthy Foods You Should Eat to Be Smarter

Our health, beauty and even our mood are highly dependent on what we consume daily, that’s why it’s important to pay more attention to the foods we include into our daily diet and make the right choice. Do you know that some foods can make you smarter? By eating them you will boost your brain’s activity and you’ll be able to stay alert during your working day. If you feel that your thinking ability is reduced after your everyday meals, you should certainly consider your eating plan. Everybody knows that fast food influences badly our waistline, but only a few of us know that it is harmful to our brain either. That’s why it is necessary to eat foods that are rich in protein, fiber, antioxidants and vitamins regularly. Only this way, you will supply your brain with all the nutrients it needs. Make sure you add the following 10 foods to your eating plan and you’ll be amazed with your brain’s power.

1. Fish
Conducted researches have proven that those people who often consume fish are less subjected to such health problem as dementia. Consequently, if you increase your fish intake, your brain will perform much better while you are working or learning lessons.

2. Oatmeal
I should say it is one of the most popular foods we usually have for breakfast. But lots of people make a big mistake when they choose different kinds of sweet crunchy flakes to eat in the morning. Surely, this food is very tasty, however your brain won’t benefit from it as such breakfast will raise your blood sugar that can result in a sudden crash. On the other hand, oatmeal is the perfect food to start your day with. Being a slow-digesting food oatmeal will provide your brain with energy for a long period of time.

3. Nuts
It is typical of most people to have numerous snacks at work. Unfortunately, we rarely think of what we eat during short breaks in the office and as a result we give preference to various candies or biscuits that are not so good for our health. It would be nice to regale yourself with some nuts if you want to have a more productive day. All those sweet snacks are full of sugar and due to this they can give you some energy, but it will finish soon. When you will replace those empty calories by healthy fats that nuts contain, you will greatly improve your thinking ability. In spite of all the benefits nuts have, you shouldn’t consume them excessively, a handful per day will be quite enough for you. Before switching to these yummy and wholesome snacks you’d better learn which nuts are good and bad for your health.

4. Chocolate
It’s rather difficult to find a person who doesn’t like chocolate. You’ll be surprised to discover that this delicious dessert can also increase your brain’s power and help your body to work more efficiently. You can get all the healthy nutrients of this sweet product not only from chocolate bars, but from hot cocoa as well. According to scientific studies this drink is perfect for elderly people as it improves their brain blood flow providing them with better memory.

5. Eggs
Perhaps you don’t even guess that eggs are among those foods that should be necessarily added to your diet. To dispel all your doubts I’d like to mention that eggs are an incredible source of chlorine. This substance is necessary to strengthen your brain’s activity and memory. Scientists claim that high concentration of chlorine found in eggs will help you to avoid the risk of brain changes that can lead to dementia.

6. Tea
If you are one of those people who can’t wake up easily in the morning and need some extra help to boost their energy, have a cup of green tea and your brain will work perfectly. By drinking green tea you will supply your body with a great deal of antioxidants that your brain needs to produce neurons. Plus, there are so many other nutrients in green tea that make it extremely effective when it comes to degenerative diseases and memory loss.

7. Leafy Greens
I would recommend you to make a salad of leafy greens for your lunch. It will be a nice alternative to fried potatoes and what is more important this food will be an excellent fuel for your brain. Try to eat more vegetables such as collard, spinach, kale, mustard greens and you will get maximum antioxidants to stimulate your brain’s activity. If you increase your daily intake of these leafy vegetables, you’ll protect yourself from memory loss.

8. Berries
What can be healthier than fresh fruits and berries? To my mind, these foods will be the best option for your dessert as they are packed with different vitamins and other nutrients that help your body function well. There are dozens ways you can enjoy sweet taste of your favorite berries. For instance, you can add them to your oatmeal for breakfast. Plain yogurt with some berries will be a delicious treat for you too. Plus, you’ll be surprised to know that this natural food has anti-aging effect. Isn’t it a valid reason for you to start eating berries right now?

9. Water
Lack of water in your body is dangerous for your health. Therefore, you should always control your water intake in order to prevent dehydration. Otherwise, you won’t be able to concentrate your attention and it can be a problem for you to recollect some information. Drink at least 8 glasses of water every day to keep your body and brain hydrated.

10. Coffee
It is considered that coffee is one of those things that influence our body ruinously. It will certainly damage your health if you are addicted to this hot drink. Whenever you feel tired and don’t have enough energy to carry out your tasks, have a cup of coffee and your working ability will grow immediately.

You can be sure that all these foods will make you smarter and give you extra energy to work productively in the afternoon. Try to include at least one of these foods into your lunch and you will never be exhausted at your workplace. What do you usually eat for lunch? Does this food help you to stay active throughout your working day? Which of the above foods do you find the most efficient and the healthiest choice?

10 Foods to Eat to Trim Down Your Body Naturally

Nowadays most of us have busy schedules and we don’t pay enough attention to our health. As we know, nutrition is the most significant part of our physical and emotional well-being, and it’s important to eat well even if you are on a diet. The main thing is to trim down your body the natural and healthy way and do it step-by-step that is quite difficult at times. Just look for all the best foods that make your body work like as a clock. Don’t be too strict and avoid suffering from poor nutrition and going hungry the whole day. Remember, wealth is nothing without health. So make sure you eat healthy and trim down your body naturally. Try to enrich your dishes with foods that support your physical well-being and help drop those unwanted pounds. You won’t have a feeling like you are a diet slave and there’s no need to stay hungry. Combine these foods with your snacks and meals and enjoy the process of losing weight with little efforts.

1. Oats
A steaming bowl of fresh cooked oatmeal is the best way to gain the strength and energy to start off your active day. Oats are very easy to digest and always fulfill you with a great portion of healthy substances. If you start your morning with a nutritious, fiber rich meal such as oats, you will never have problems with maintaining a healthy weight.

Oats are a great source of magnesium, phosphorus and selenium. They contain a lot of iron and vitamin B1, too. Plus, oats are fat-free, having a lot of healthy minerals and vitamins. You can use oats in different dishes; add them to cookies, muffins, chicken omelets and smoothies. Oats stabilize the level of sugar in your blood and increase your fiber and protein intake. Nowadays many people eat oat meals in the morning and take it as a rule. We should know that oats are extremely useful for our health and they are one of the best foods to eat to trim down your body naturally.

2. Fish
Fish is considered to be a super nourishing food that can help you drop a few unwanted pounds as quick as possible. It increases and repairs your lean muscle mass due to its amino acids content. Not to become bored with constant fish dishes, you can pair it with some other healthy foods. Fish is low in calories so don’t be afraid of getting fat, furthermore it contains no carbs at all. If you are anxious about fast weight loss, you should be sure that choosing other kinds of meat is not the best option.

They say that fish is an indispensable element of nutrition. It is packed with vitamins and minerals. Moreover, containing a huge amount of omegas 3, fish can help us protect against a range of diseases. Omega 3 fatty acids are believed to raise levels of the brain chemical serotonin that can help to ease depression. Be sure that fish is a super-food that can trim down your body quickly and help you to be healthy.

3. Berries
It seems berries are the most delicious food to eat to trim down your body naturally. They are extremely low in sugar and help burn fat cells as well. Berries raise the level of serotonin, making your mood majestic and stable to stresses. They contain a great number of vitamins, minerals and are rich in antioxidants, including quercetin, anthocyanins and vitamin C. All these elements help release toxins from a set of cells in the body.

Berries are “juicy foods” because they contain mostly water, that’s why they are great for losing weight. Moreover, berries contain folate and fiber that help us lower the level of cholesterol and normalize blood pressure. You can add berries to different dishes, cakes, cocktails, beverages and cookies. Remember that berries can be frozen to get them in usage during off-season months.

4. Greens
Many people find greens the most effective way to trim down the body. Greens are incredibly low in calories and can help keep you full longer. Greens balance your body, regulate different physiological processes and make your mind bright. Greens are full of antioxidants, minerals and vitamins that protect and restore your skin and body cells. They contain a high level of nutrients. When you eat greens, your body does not require more signals to eat, as a result, you feel full and don’t overeat.

Greens reduce the risk of heart disease, including heart attack and stroke. Moreover, they help reduce blood cholesterol levels. As we see, eating greens is one of the best ways to stay healthy and lose weight. They are a rich source of minerals, including calcium, magnesium, iron and vitamins such as C, K, E and B group as well.

5. Coconut
Coconut is a very special and delightful food to eat to trim down your body naturally. If you didn’t know, the palm tree is believed to be “The Tree of Life.” Coconut is good for your immunity, having antibacterial and antiviral effects. It boosts your mental activity, protects from stress by reducing the level of cortisol in your blood and keeps your mood in order.

Coconuts are an excellent source of fiber, minerals, amino acids and vitamins. They are packed with potassium, magnesium, calcium and a set of electrolytes. Coconut is used in many forms like oil, milk and butter. Eating coconuts supports the structure and development of healthy and strong teeth and bones. Coconut has useful antioxidant properties that slow down the aging process. It is a quick energy source and many people find it extremely nourishing.

6. Cucumbers
I think everyone loves cucumbers. They are so useful and rich in helpful elements and minerals, such as vitamin C and potassium. Cucumbers are good for your health and they can help you shed a few unwanted pounds fast. Just be aware that they are often sprayed with pesticides, so try to buy organic ones. Due to their low calorie and high water content, cucumbers aid in digestion and weight loss. Did you know that cucumbers eliminate bad breath? Take a slice of it and press in to the roof of your mouth with the tongue for a minute. Its chemicals will kill bacteria in your mouth.

Apart from weight loss, cucumbers boast numerous benefits. They are high in sulfur and silicon that help to stimulate hair growth. Cucumbers are also used to ease sunburns and skin irritations. Add them to your green smoothies, vegetable salads or eat them raw.

7. Egg whites
Egg whites contain a lot of proteins and don’t have many calories. One egg has only 71 calories and it’s one of the best foods to add to your healthy diet. An egg white contains selenium, magnesium, phosphorus and calcium. Egg whites can be used in various recipes. Eat them in the morning and they will leave you feeling much fuller than breakfast cereals. Egg whites also contain small amounts of vitamin B which is healthy for your body.

8. Lemons
Lemons reduce stress due to their vitamin C content and burn fats with lightning speed. Lemon juice with a pinch of salt every morning lowers cholesterol levels and brings your weight down. Lemons are high in antioxidants that fight off free radicals, preventing many diseases, including cancers, stroke and cardiovascular diseases. If you feel that you are getting ill, try to start curing yourself with help of lemons. Lemon helps produce antibodies in blood that attack the invading micro organism and fights the infection. Add a few drops of lemon juice in hot water to purify the liver and clear the digestive system. Lemon is one of the best fat burning foods that can help you trim down your body naturally.

9. Veggies
Veggies can be freely paired with greens to make your nutrition full and balanced. Everyone has their own favorite set of veggies. I prefer carrots, beets, celery, turnips and potatoes. I’m sure everyone knows about enormous benefits of Brussel spouts, onions, broccoli and cabbages. They are extremely nutritious and contain a great number of vitamins, fiber and water. All these elements and minerals fill your body up and help trim down the body naturally.

Veggies are also high in folate, potassium and vitamins A, E and C. The proverb says: “A sound mind in a sound body.” Try to add more veggies and greens to your eating plan and you will notice the improvement in a quite short period of time.

10. Nonfat Greek yogurt
Everyone seems to like nonfat Greek yogurt it’s a great snack that is low in sugar, calories and high in protein. It’s also packed with potassium, calcium, magnesium, iron, zinc, vitamin D and B 12. Nonfat Greek yogurts are essential, especially for women. Add your favorite berries to your yogurt and you will have a wonderful snack that will help you trim down your body naturally.

Trimming down your body doesn’t have to be difficult. You just need to eat healthy and exercise regularly. Include these foods to your eating plan and you will see how it’s easy to be slim and healthy. What’s your favorite way to trim down the body naturally?

Invasive Atlantic Salmon Escape West Coast Fish Farm, Available For Capture

Photo: Eric Kilby on Flickr.

Thousands of invasive Atlantic salmon are on the loose in the Pacific Ocean, and the results could be catastrophic. However, you can help alleviate the invasive Atlantic salmon escape and feed yourself at the same time.

According to the Seattle Times, up to 305,000 Atlantic salmon broke loose from a local Washington farm last weekend. The salmon are currently heading to the Pacific Ocean, and many are likely already out there flourishing.

The salmon made their escape following a net breakage at a fish farm belonging to Cooke Aquaculture. Interestingly, the company blames the eclipse for high tides that gave the fish ample opportunity to break loose. Initially, estimates of Atlantic salmon loss stood at 4,000 to 5,000 fish. However, the company now fears that hundreds of thousands of fish could have escaped.
Because Atlantic salmon are not native to the Pacific, environmental damage could possibly occur. Environmentalists are particularly concerned about the Atlantic fish mating with Pacific Chinook salmon and stealing their food. Estimates put the environmental fallout between moderate and very serious, according to the Guardian.

To help alleviate the problem, the Washington Department of Fish and Wildlife is asking the public to help catch the Atlantic salmon. If you have a fishing license, you can catch as many Atlantic salmon as you please.

Hopefully, this will help prevent too many invasive fish from harming the Pacific Ocean’s natural environment.

Fermented Cod Liver Oil vs. Fish Oil

Fermented Cod Liver Oil is one of the very few things that I take daily and give to my kids (starting at a few months old). I get quite a few emails asking why I take this particular one and if regular fish oil would work just as well. I’m not a doctor and I’m not trying to play one on the internet, so I’m just sharing the reasons that my family takes Fermented Cod Liver Oil.

Why Fermented Cod Liver Oil?

Fermented cod liver oil is made when cod livers are fermented. This allows the fat soluble vitamins and beneficial oils to separate from the rest of the liver without damaging the fat soluble vitamins (unlike in some methods like heat processing where the vitamins are damaged). This cool temperature fermentation process allows the cod liver oil to maintain its Omega-3, Vitamin D and Vitamin A content. This also makes the nutrients more absorbable to the body as Diane of Balanced Bites explains:

In our bodies, digestive breakdown is the mechanism by which we do this internally – by means of not only the physical churning in our stomach, but also by means of stomach acid, bile, and, perhaps most notably digestive enzymes. There are several ways in which the reduction of nutrients may occur: heat, synthetic chemical processing, and digestion (or fermentation, which is an exogenous means of pre-digesting nutrients). Heat is damaging to delicate nutrients, especially when they are isolated from their whole-food source. Synthetic chemical breakdown of nutrients is damaging as well.

Digestion or fermentation (enzymatic breakdown) is by far the safest and most effective way to reduce the molecular structures in foods to their end usable constituents. (If you are an organic chemistry-buff, perhaps you’ll know a lot more about what the following information means than I do) When reduction is initiated by digestion (digestive enzymes) or fermentation, 100% of molecules break “to the right” – which is how our body uses them best. When the reduction is initiated by either heat or synthetic chemicals, 50% of the molecules break to the left (which may be toxic or unhealthful at the very least) and 50% to the right.

Vitamins in FCLO:

Many healthcare professionals recommend taking Omega-3s in some form, and after researching the processing and Omega-3 levels in Fermented Cod Liver Oil, I decided that it was the best option for our family for several reasons:

Unlike many Omega-3 supplements, Fermented Cod Liver Oil is cold processed through fermentation so it retains high levels of fat soluble vitamins and Omega-3s and these are not damaged by high temperatures. Additionally, Fermented Cod Liver Oil contains about 25% DHA and EPA, which are highly recommended forms of Omega-3s.
Fermented Cod Liver oil Contains Vitamins A and D, which are both necessary for many aspects of health. While we can get Vitamin D from sunlight, Vitamin A can be harder to consume or absorb and FCLO is an excellent source. Vitamins A and D need each other for proper absorption as the Weston A. Price Foundation explains:”At least 2,000 genes, or nearly 10 percent of your genes, have been identified that are directly influenced by vitamin D, which in turn impact a wide variety of health issues, from preventing the common cold and flu to inhibiting at least sixteen different types of cancer. There’s even evidence linking vitamin D to the process of brain detoxification of heavy metals such as mercury. Widespread vitamin D deficiency has also been strongly linked to the childhood epidemics of autism, asthma, and diabetes, both type 1 and 2. Vitamin A, which is essential for your immune system just like vitamin D, is also a precursor to active hormones that regulate the expression of your genes, and they work in tandem. For example, there is evidence that without vitamin D, vitamin A can be ineffective or even toxic. But if you’re deficient in vitamin A, vitamin D cannot function properly either.”
Vitamin A (found abundantly in Fermented Cod Liver Oil) is a vital nutrient for our bodies, but it can be difficult to obtain. From The Healthy Baby Code: “Beta-carotene is the precursor (inactive form) of retinol, the active form of vitamin A. While beta-carotene is converted into vitamin A in humans, only 3% gets converted in a healthy adult. And that’s assuming you’re not one of the 45% of adults that don’t convert any beta-carotene into vitamin A at all.This means that – contrary to popular wisdom – vegetables like carrots and red peppers are not adequate food sources of vitamin A.Vitamin A is found in significant amounts only in animal products like liver and grass-fed dairy. You’d have to eat a huge amount of beta-carotene from plants to meet vitamin A requirements during pregnancy. For example, 3 ounces of beef liver contains 27,000 IU of vitamin A. As the chart below illustrates, to get the same amount of vitamin A from plants (assuming a 3% conversion of beta-carotene to vitamin A), you’d have to eat 4.4 pounds of cooked carrots, 40 pounds of raw carrots, and 50 cups of cooked kale!”
The Studies on FCLO

According to the Weston A Price Foundation, recent studies have shown that Fermented Cod Liver Oil can be beneficial to those with certain conditions including:

“PAIN IN RHEUMATOID ARTHRITIS: Cod liver oil supplements were better than controls in relieving pain and can be used as NSAID-sparing agents in rheumatoic arthritis patients (Rheumatology (Oxford). 2008 May;47(5):665-9).
VITAMIN D STATUS AND BONE LOSS: Inclusion of cod liver oil in the diet appears to attenuate the seasonal variation of vitamin D status in early postmenopausal women at northerly latitudes where quality of sunlight for production of vitamin D is diminished. Cod liver oil can thus protect against greater bone turnover, bone loss and obesity (Bone. 2008 May;42(5):996-1003).
DIABETES-RELATED CARDIOVASCULAR DISORDERS: Cod liver oil treatment in diabetic rats completely prevented endothelial deficiency and partly corrected several biochemical markers for cardiovascular disorders (J Pharm Pharmacol. 2007 Dec;59(12):1629-41).
MULTIPLE SCLEROSIS: In Arctic climates, supplemental cod-liver oil during childhood may be protective against multiple sclerosis later in life (J Neurol. 2007 Apr;254(4):471-7).
BREAST CANCER: Reduced breast cancer risks were associated with increasing sun exposure and cod liver oil use from ages ten to nineteen. “We found strong evidence to support the hypothesis that vitamin D could help prevent breast cancer. However, our results suggest that exposure earlier in life, particularly during breast development, maybe most relevant” (Cancer Epidemiol Biomarkers Prev. 2007 Mar;16(3):422-9).
DEPRESSION: Regular use of cod liver oil is negatively associated with high levels of depressive symptoms in the general population (J Affect Disord. 2007 Aug;101(1-3):245-9).
WOUND HEALING: The combination of zinc oxide and cod liver oil was found to be superior to the formulations containing only one active ingredient. This combination was also found to be most efficient in accelerating wound healing when it is retarded by repeated dexamethasone treatment (Dtsch Tierarztl Wochenschr. 2006 Sep;113(9):331-4).
BREAST MILK: Women using cod liver oil had a significantly higher levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in their breast milk. “As this may have an impact on the health and development of breast-fed infants in later life, regular maternal cod liver oil intake could be relevant for the infant as well as for the nutritional adequacy of the maternal diet” (Ann Nutr Metab. 2006;50(3):270-6).
PAIN AND JOINT STIFFNESS: Cod liver oil application allows reduction of the dose of nonsteroidal anti-inflammatory drugs, and improves chief clinical symptoms, reducing pain and morning joint stiffness (Klin Med Mosk2005;83(10):51-7).
HIP FRACTURE: Multivitamin or cod liver oil supplementation was associated with a significantly lower risk of any fracture. “We found no evidence to support any skeletal harm associated with increased serum indices of retinol exposure or modest retinol supplementation in this population” (J Bone Miner Res. 2005 Jun;20(6):913-20).
HIGHER BIRTH WEIGHT: Women who used liquid cod liver oil in early pregnancy gave birth to heavier babies, even after adjusting for the length of gestation and other confounding factors. “Higher birth weight has been associated with a lower risk of diseases later in life and maternal cod liver oil intake might be one of the means for achieving higher birthweight” (BJOG. 2005 Apr;112(4):424-9).
UPPER RESPIRATORY TRACT INFECTIONS IN CHILDREN: Children supplemented with cod liver oil had a decrease in upper respiratory tract infections and pediatric visits over time (Ann Otol Rhinol Laryngol. 2004 Nov;113(11):891-901).
VITAMIN D STATUS: In Norway, three mølje meals (consisting of cod liver and fresh cod-liver oil) provided an amount of vitamin D equal to 54 times the recommended daily dose. Subjects with food consumption habits that included frequent mølje meals during the winter sustained satisfactory vitamin D levels in their blood, in spite of the long “vitamin D winter” (Public Health Nutr. 2004 Sep;7(6):783-9).
DIABETES: Use of cod liver oil in the first year of life was associated with a significantly lower risk of type 1 diabetes. Use of other vitamin D supplements during the first year of life and maternal use of cod liver oil or other vitamin D supplements during pregnancy were not associated with lower risk of type 1 diabete (Am J Clin Nutr. 2003 Dec;78(6):1128-34).
INTELLIGENCE IN CHILDREN: Children who were born to mothers who had taken cod liver oil during pregnancy and lactation scored higher on intelligence tests at age four compared with children whose mothers had taken corn oil (Pediatrics. 2003 Jan;111(1):e39-44).
RHEUMATOID ARTHRITIS: Use of cod liver oil decreased occurrence of morning stiffness, swollen joints and pain intensity in patients suffering from rheumatoid arthritis (Adv Ther. 2002 Mar-Apr;19(2):101-7).
EAR ACHES IN CHILDREN: Children prone to ear aches (otitis media) receiving cod liver oil plus selenium needed lower amounts of antibiotics during supplementation compared to before supplementation (Ann Otol Rhinol Laryngol. 2002 Jul;111(7 Pt 1):642-52).
DIABETIC NEUROPATHY: Use of cod liver oil in mice played an important role in the prevention of diabetic nephropathy (Lipids. 2002 Apr;37(4):359-66).
FAT-SOLUBLE VITAMINS IN BREAST MILK: Maternal use of cod liver oil resulted in higher levels of fat-soluble vitamins in breast milk, especially vitamins E and A. (Ann Nutr Metab. 2001;45(6):265-72).” (source)
What Fermented Cod Liver Oil We Take

My family takes Fermented Cod Liver Oil daily. I’ve only found one brand that is manufactured with the cold process fermentation (in the US) and this is Green Pastures (we order ours here). There are several options for Fermented Cod Liver Oil and we typically take the Fermented Cod Liver Oil/High Vitamin Butter Oil Blend. The High Vitamin Butter Oil has Vitamin K2, another fat soluble vitamin which Dr. Price called “Activator X” and which has been shown to help improve heart, bone, immune, brain and other aspects of health (source). For our family personally, this is what we take daily (ask your doctor before taking any new supplements!):

My husband and I take 1 teaspoon of the Fermented Cod Liver Oil  Butter Blend everyday
Kids 2 and under (up to 30 lbs) get 1/4 tsp per day
Kids 3 and up (over 30 lbs) get 1/2 tsp per day
Kids 6 and up (over 50 lbs) get 2/3-3/4 tsp per day
I take up to two teaspoons if pregnant/nursing or trying to remineralize teeth
We use the Green Pastures brand of Fermented Cod Liver Oil (usually with High Vitamin Butter Oil added) which I get from here.

Vitamin A Concerns?

Some sources question the safety of consuming regular doses of Vitamin A. After much research, this doesn’t concern me when taken from a healthy source (like fermented cod liver oil) since it has Vitamin A and Vitamin D in synergistic doses. I also make sure to include organ meats and other sources of fat soluble vitamins in our diet. Chris Kresser has a great post that addresses many of the Vitamin A concerns here.

Sources and More Reading:

-“The Cod Liver Oil Debate” by Chris Masterjohn on the Weston A. Price Foundation website
-“A Response to Dr. Mercola on Cod Liver Oil” from the Weston A. Price Foundation website
-“Separating Fact from Fiction on Cod Liver Oil” from Chris Kresser
-“On the Trail of the Elusive X-Factor” by Chris Masterjohn
-“Vitamin K2 – The Missing Nutrient” by Chris Kresser
-“All About Fermented Cod Liver Oil and Why I Don’t Take Fish Oil” by Diane Sanfillipo of Balanced Bites

Other posts I’ve written about our use of Fermented Cod Liver Oil

How to Remineralize Teeth Naturally
Supplements I Take Daily
Supplements for Pregnancy and Nursing
Healthy Teeth From the Inside Out
Eat Your Sunscreen
9 Tips to Balance Hormones Naturally

The Problems with Fish Farming

We have all heard the recommendation to eat more fish and seafood. Why? Because fish, especially oily fish like salmon, are a rich source of Omega-3 fatty acids DHA and EPA which may help protect the body against heart disease, high blood pressure, inflammation, brain health, diabetes, digestive disorders and even autoimmune disease.

My family loves seafood, but there are some considerations regarding fish farming I try and take into account before purchasing and preparing it.

In 2009 Americans consumed 15.8 pounds of fish and shellfish per person, 4.833 billion pounds of seafood in total. Per week, Americans eat about 3.5 ounces of seafood, which is still only half of what the USDA recommends. (17)

Unfortunately, not all fish are created equal as commercial fish farming practices have affected many fish populations and changed the fish supply substantially. It can also be difficult to find quality seafood and decipher labels to know where they were sourced. Among the many labels are wild-caught and farm-raised. It’s tempting to opt for farmed-raised, as often the wild-caught fish cost twice as much!

Is Farmed Fish a Healthy Choice?

Aquaculture is the practice of raising fish or ocean plants for food or resources. Today, many species of fish are raised in contained fresh water or ocean water environments, including salmon, catfish, tilapia, cod and others.

In fact, around 50% of the seafood we consumes comes from aquaculture. It is a $78 billion industry which has grown 9% a year since 1975. (6)

While aquaculture is nothing new as humans have been farming fish for millennia, there have been some substantial changes in recent decades. There is evidence of fish farming dating back to 2000 BCE in China and depictions of ornamental fish ponds in ancient Egyptian paintings. (12, 13)

Modern fish farming practices often raise fish near the top of the food chain (affecting populations of fish that eat or are eaten by these species) and contain thousands of fish in tiny pens (similar to commercial chicken or cow operations). As you may imagine, these conditions leave something to be desired and affect both the quality of the fish and the health of the ocean.

Environmental Problems with Fish Farming

Fish farming is a way to create a much larger amount of fish much more quickly, cheaply and efficiently than with wild caught fish. Unfortunately, when something seems to good to be true, it very often is!


This density of fish creates problems like disease and pollution. The biggest source of pollution is the accumulation of fish waste and uneaten food beneath the sea pens which can degrade the quality of the surrounding water.

Like commercial farming operations on land, the density of  fish in these pens necessitates certain chemicals to keep animals from getting sick and to keep things clean. The chemicals used in marine aquaculture operations such as medicines like antibiotics and vaccines, disinfectants, and substances used to prevent corrosion of equipment (cages, etc.) can also change the composition of the surrounding aquatic ecosystem.

The amount of pollution from fish farms also depends on how the fish are contained. Open-net, or pen systems, allow for a direct exchange of water, where as “closed contentment” methods have a barrier which filters the water.

Impact of Biodiversity

Another way aquaculture can have a negative impact is by introducing farmed species into the wild and therefore changing the biodiversity of aquatic ecosystems. Even when measures are taken to prevent escapes, predators like birds and sharks, equipment failure, human error, severe weather and other complications mean that escapes of farmed fish are inevitable.

Since farmed fish often have been bred via selective breeding they have a lower genetic variation than wild fish. If they interbreed with the wild fish it can result in a less genetically diverse, and therefore less robust, population.

Another concern is infertile offspring. For example, Atlantic and Pacific salmon belong to different genera and while they can produce offspring, those offspring will be unable to reproduce (like mules). If populations of non-native species become established they compete with native populations for resources such as food and breeding sites. (8)

Since farmed fish are selected and bred for certain genetic criteria like size, quick growth and hardiness, escaped species can become invasive, which has been recognized as one of the main causes of global biodiversity loss. One example of this was the Pacific oyster in the UK, which was introduced into its waters in the 1960s via aquaculture with the idea that it would be a more commercially viable species than the native oyster. Unfortunately, these pacific oysters have spread and created reef formations, forcing out the native oysters and altering the marine environment.

Tilapia Takeover

Another example of the negative effect of fish farming on native fish population and environment is with Tilapia. Tilapia is one of the most common types of farmed fish. Most of our tilapia supply is imported from Latin American and Asia, and in 2015, Americans ate 475 million pounds of tilapia.

Tilapia is a warm-water fish native to Africa, but in the last 60 years the governments of poor tropical countries saw the fish as a solution to control weeds and mosquitoes in lakes and rivers, breeding and releasing tilapia into these areas. They are now seen as a nuisance, as they are one of the “most invasive species known and difficult to get rid of once established,” says Aaron McNevin, a WWF biologist.

In Lake Apoyo in Nicaragua, tilapia escaped from a fish farm and their pollution and feeding reduced the lake’s quantity of an aquatic plant called charra, which was an important source of food for the lake’s native fish populations. Sixteen years later, the lake’s biota are still recovering. (3)

Spread of Disease & Antibiotic Use

Because farmed fish are raised on unnatural diets and in small enclosures they often breed disease, which can pass to wild populations. This is becoming an increasingly big problem, as are the solutions often used for these diseases.

Some aquaculture productions rely on prophylactic antibiotics to prevent infections. The use of antibiotics can cause drug resistant bacteria to develop which can spread to wild populations. (1, 2)

Sea Lice

Another common disease is sea lice. Not to be confused with an itchy, stinging rash caused by jellyfish larvae, these sea lice are planktonic marine parasites which feed on many types of fish. There are many species but the common “salmon louse” or lepeophtheirus salmonis, has become a big problem for both wild and farmed salmon populations. About a centimeter in size, the sea lice attach themselves to the outside of a fish and feed on its mucous, blood, and skin. (16)

This can cause serious damage to fins, erosion of skin, constant bleeding, and open wounds at risk of infection. On an adult fish this may be only a nuisance, but for small juvenile salmon (around the size of a finger), sea lice can be fatal. (15)

Before offshore industrial scale fisheries became big business in the 1970s, sea lice were rarely epidemic to fish populations. Of course, when hundreds, or even thousands of fish are crowded together in a small area, sea lice, and other diseases can easily spread from fish to fish. (14)

This problem not only impacts food supply and fish industry profits, it is spreading to wild fish populations. One example is the salmon in the Broughton Archipelago, a group of islands 260 miles northwest of Vancouver, British Columbia.

In 2007 the area had 20 active fish farms, which raised between 500,000 and 1.5 million fish each. As juvenile wild salmon swam past these open-net farms on their way down river towards the sea, the sea lice infecting the farmed salmon attached to them. A study done that year found that the number of wild pink salmon were down 80% since 1970 because of sea lice infestations. The study concluded that at this rate the wild salmon in the area would die off in four generations or by 2015. While the conclusions of this study were not without controversy, it did seem that the salmon populations recovered when the farms idled. (15)

Pesticide Use

As sea lice became a problem in fisheries around the world, an unfortunately common solution was employed: pesticides. One chemical commonly used was emamectin benzoate, or Slice, which when administered to rats and dogs causes tremors, spinal deterioration and muscle atrophy.

Of course soon the lice became resistant, and Slice only worked in triple doses. Other chemicals like hydrogen peroxide, Salmosan, AlphaMax and Calicide chemicals have been employed instead.

While we know that these chemicals can negatively affect ocean water and plant species, we don’t have enough research to know how much of these chemicals are absorbed and retained by the fish and if any of this passes to those who eat the fish. (14)

Fish Farming: Effects on Fish

As you might imagine, most species of fish don’t thrive when being raised in extremely cramped pens, fed commercial feed, and treated with pesticides, antibiotics and other chemicals. We now know that thees modern practices negatively affect the fish as well as their environment.

Higher Levels of Omega-6

Like all animals, fish are what they eat. The nutrition of our food depends on the nutrition of our food’s food. For example, salmon in the wild eat smaller fish, which eat aquatic plants rich in beneficial long chain omega-3 fatty acids DHA and EPA. Farm-raised salmon eat pellets, and as the nutritional quality of pellets varies, so does the nutritional quality of the fish. Often young salmon are fed pellets made from plant and animal sources, and they receive more expensive fish/fish oil enriched pellets later in their lifespan just before harvest. (7)

New commercial fish feeds are more likely to have protein and oils derived from grains and oilseeds (like soybeans and canola) and with less fishmeal and fish oil. The difference in feeds accounts for why one study that measured the omega-3 contentment of fish species from six regions of the US found large variations in the omega-3 content in the five salmon species tested. (7, 8)

In the two farm raised varieties tested the omega-3 ranged from 717 mg to 1,533 mg per 100 grams of fish (which is equal to a 3.5 oz serving). Compared to the wild-caught varieties, these farmed fish tended to have higher levels of omega-3s but only because the farmed salmon have more fat overall, including higher levels of omega-6 polyunsaturated fats and saturated fats. (7)

Feeds from vegetable sources can be more sustainable than fishmeal and fish oil. These are often made from smaller fish, lower on the food chain which are sometimes called reduction, pelagic, or trash fish. To create 1kg (2.2 lbs) of fishmeal it takes 4.5 kg (10 lbs) of smaller fish. In fact, today at least 37% of global seafood is ground up to make feed. In 1948 that number was only 7.7%. (4)

These lower food chain fish are the food for many species of aquatic life, and depleting them may cause serious implications for aquatic ecosystems and other sea animals including birds and mammals. (6)

PCBs and POPs

PCBs (polychlorinated biphenys) are industrial pollutants that find their way into fresh waters and oceans and then are absorbed by aquatic wildlife. PCBs are a type of POP (persistent organic pollutant). (10)

Type 2 diabetes and obesity have been linked to POPs, and certain types increase the risk of stroke in women. PCBs are potential human carcinogens, and known to promote cancer in animals. Other potential health effects include negative effects on the reproductive, nervous, and immune systems plus impaired memory and learning. (9, 10)

One study found that PCB levels in farmed salmon, especially those in Europe were five to ten times higher than PCBs in wild salmon. Follow-up studies haven’t confirmed this, and there are now strict rules on contaminant levels in feed ingredients which have lowered PCBs in these fish. (8, 9, 10)

It is best to avoid these chemicals completely, but most PCBs are found in the skin, so if farmed raised fish is the only option available, it is possible to reduce exposure by removing the skin and by avoiding fried fish. (10)

Things to Consider When Selecting Seafood

As if the various concerns associated with fish farming weren’t enough, there are other important factors to consider when sourcing any kind of seafood.


Mercury toxicity can impact brain development in children and negatively affect cognitive function in adults. Mercury is found in the muscle of the fish. The biomagnification of mercury means that organisms higher on the food chain contain higher levels of the metal. (5, 10)

One way to consume seafood yet reduce mercury exposure is by eating smaller fish lower on the food chain, such as sardines. See the resources section at the bottom of this post for a list of fish ranked by their mercury levels.

The Selenium Myth

Many of us in the real-food community have heard that mercury is only a concern if there is not selenium present in the fish, and since most seafood also has high levels of selenium we shouldn’t be concerned about mercury.

Dr. Christopher Shade, recently confirmed in an interview with Chris Kresser that this is not the case. He verified that those who are deficient in selenium will be more susceptible to mercury toxicity; however, having good selenium levels doesn’t prevent someone from getting mercury toxicity from seafood. Nor does the selenium in seafood bind the mercury and therefore prevent us from absorbing the toxic metal. (5)

One important way the body rids itself of mercury is via glutathione, the body’s self produced master-antioxidant. It is therefore important to support this pathway by consuming sulfur containing vegetables like onions and brassicas, and good amounts of vitamin C.

Omega-3 Levels

Omega-3s are very important for health, and should be consumed in proper ratio with Omega-6 fatty acids. Statistically, most of us consume too much Omega-6 and not enough Omega-3, which some experts blame as one of the root causes of many modern diseases. Fish are an excellent natural source of Omega-3s, but there is a wide range of levels depending on the fish. When choosing seafood, it helps to know which fish have the highest levels of these beneficial fats. (For a list of fish ranked by levels of Omega-3s see the resources section at the end of this post.)


While farmed fish have obvious drawbacks there are also sustainability concerns about wild caught fish.

One of the major concerns is overfishing which has become a global problem. Obviously it becomes difficult to eat the fish if they don’t exist, but fewer populations of certain species can have repercussions for an entire ecosystem. (19)

Another issue is bycatch, which is when non-target animals are caught during fishing. This can include dolphins, sea turtles, birds, sharks, stingrays, and other fish like juvenile fish.The incidence of bycatch can be reduced by the use of selective fishing gear designed to catch only the species selected and implementing measures to return the native species.

Habitat destruction can degrade aquatic ecosystems, as seabed habitats provide shelter and food for a variety of species. One fishing method that is a common culprit is bottom trawling near vulnerable areas like coral reefs or breeding and nursing grounds. (19)

By now your head is probably spinning and you are asking yourself: So how do I know if the seafood I’m buying is both responsible and healthy? Do these even exist?

As you can see, it is a complex issue. It goes beyond farmed or wild-caught and can change depending on the region where the fish is caught, the variety, the producer, and so on.

Canned Seafood Considerations

Buying canned fish is a good way to eat high quality fish on a budget. However, sure to select cans that are BPA free. Another thing to look for is if they are canned in oil, as to preserve omega-3s it is typically preferable to purchase fish that is canned in water.

Resources for Finding Quality Seafood

Seafood Watch  makes choosing seafood a lot easier. Seafood is labeled as either green (best choice), yellow (good alternative) and red (avoid) depending on the variety’s sustainability. They then list the fishing method, and the location. They also have an app for your smartphone (search your app store).

Natural Resources Defense Council has several guides to avoid mercury consumption in fish including a detailed guide for pregnant women and this PDF is a good quick reference guide.

The Safina Center ranks seafood on both sustainability and mercury/PCB contamination.

Mercury Levels of Commonly Consumed Fish

Mercury levels can vary greatly among different types of fish. The following list groups seafood by mercury content, and please note these other criteria:

*Caught using unsustainable or environmentally damaging methods.
**Farmed Salmon

Least Mercury: Consume Freely

Crab (Domestic)
Croaker (Atlantic)
Haddock (Atlantic)*
Mackerel (N. Atlantic, Chub)
Perch (Ocean)
Salmon (Canned)**
Salmon (Fresh)**
Shad (American)
Sole (Pacific)
Squid (Calamari)
Trout (Freshwater)

Moderate Mercury: Eat Six Servings or Less per Month

Bass (Striped, Black)
Cod (Alaskan)*
Croaker (White Pacific)
Halibut (Atlantic)*
Halibut (Pacific)
Mahi Mahi
Perch (Freshwater)
Tuna (Canned chunk light)
Tuna (Skipjack)*
Weakfish (Sea Trout)

High Mercury: Avoid When Possible

Mackerel (Spanish, Gulf)
Sea Bass (Chilean)*
Tuna (Canned Albacore)
Tuna (Yellowfin)*

Highest Mercury: Avoid Whenever Possible

Mackerel (King)
Orange Roughy*
Tuna (Bigeye, Ahi)*

Omega-3 Levels (EPA + DHA) per 3 oz Portion

When choosing seafood, it is also beneficial to choose sources that are the highest in natural Omega-3s. (18)

1,500 mg:

Herring, Wild (Atlantic, Pacific)
Salmon, Wild (King)
Mackerel, Wild (Pacific, Jack)
Salmon, Farmed (Atlantic)

1,500 – 1,000 mg:

Salmon, Canned(Pink, Sockeye, & Chum)
Mackerel, Canned (Jack)
Mackerel, Wild (Atlantic & Spanish)
Tuna, Wild (Bluefin)

500 – 1,000 mg:

Salmon, Wild (Sockeye, Coho, Pink)
Sardines, Canned
Tuna, Canned (White Albacore)
Swordfish, Wild
Trout, Farmed (Rainbow)
Oysters, Wild and Farmed
Mussels, Wild and Farmed

200 – 500 mg:

Tuna, Wild (Skipjack)
Pollock, Wild (Alaskan)
Rockfish, Wild (Pacific)
Clams, Wild and Farmed
Crab, Wild (King, Dungeness, Snow)
Lobster, Wild (Spiny)
Snapper, Wild
Grouper, Wild
Flounder/Sole, Wild
Halibut, Wild (Pacific, Atlantic)
Ocean Perch, Wild
Squid, Wild (fried)
Scallops, Wild
Shrimp, Wild and Farmed
Lobster, Wild (Northern)
Crab, Wild (Blue)
Cod, Wild
Haddock, Wild
Tilapia, Farmed
Catfish, Farmed
Mahi Mahi, Wild
Tuna, Wild (Yellowfin)
Orange Roughy, Wild
Surimi (Imitation Crab)

(Source: USDA National Nutrient Database for Standard Reference)

Any Good Options?

There may be some responsible and healthy options for farmed seafood, especially with Shrimp. A reader Linda researched one brand, Henry and Lisa’s and found this out:

“I called Henry and Lisa’s at EcoFish.com and had a long talk with them about their shrimp farm and their practices. I was very impressed with them, although it is hard to verify information from a company that is so little known. However I did find this article by the National Resources Defense Council and they have some hopeful things to say about this matter.

The article is entitled, “MEALS OF MASS DESTRUCTION: SHRIMP”. Henry Lovejoy, (founder of EcoFish and Henry & Lisa’s) is singled out in paragraphs 10 and 14 as an example of responsible shrimp farming and this company is recommended over wild caught shrimp.”

The Bottom Line on Fish Farming

So what’s the verdict?

Wild caught seafood is preferable, both for the environment and for health, as we still don’t know the full impact of large scale commercial fish farming. There are some farming techniques that may make be viable options in the future, especially for those on a budget, but current methods have a drastic impact on native seafood species and on the ocean ecosystem.

Seafood can also be a more expensive protein source, especially when choosing wild-caught options, but inexpensive, low-mercury and non-farmed canned sardines can fit into almost any budget.

When choosing wild-caught seafood, consult the above resources and decide on the varieties that work for your wallet and your taste-buds, and then go enjoy those brain-boosting Omega-3s!


1. O’Conner, Anahad. “Ask Well: Wild Fish vs. Farmed Fish.” The New York Times. 18 December 2014.
2. Food and Water Watch. “What’s Wrong with Factory Fish Farming?” 1 February 2013.
3. Rosenthal, Elizabeth. “Another Side of Tilapia, the Perfect Factory Fish.” The New York Times. 2 May 2011.
4. Stier, Ken. “Fish Farming’s Growing Dangers.” Time. 19 September 2007.
5. Kresser, Chris. Revolution Health Radio: Dr. Chris Shade on Mercury Toxicity. 12 November 2015.
6. Sustainable Seafood Coalition. “Commercial Aquaculture: Potential Environmental Issues.”
7. Corliss, Julie. “Finding Omega-3 Fats in Fish: Farmed vs. Wild.” 23 December 2015. Harvard Health Blog.
8. Washington State Department of Health. “Farmed Salmon vs. Wild Salmon.”
9. Kirpatrick, Kristin. “Fish Face-off: Wild Salmon vs Farmed Salmon.” Cleveland Clinic. 3 March 2014.
10. University of Michigan, Department of Integrative Medicine. “Healing Foods Pyramid: Fish and Seafood.”
11. SeaChoice.org. “Aquaculture Methods.”
12. Sission, Mark. “The Many Faces of Aquaculture: An Introduction to Fish Farming.” Mark’s Daily Apple.
13. Swann, LaDon. “A Basic Overview of Aquaculture.” Perdue University.
14. Philpott, Tom. “Some Sea Lice with the Farmed Salmon?” Mother Jones Magazine. 27 September 2011.
15. Roach, John. “Sea Lice from Fish Farms May Wipe Out Wild Salmon.” National Geographic Magazine. 13 December 2007.
16. Farmed and Dangerous. “Sea Lice.”
17. NOAA Fisheries. “Seafood & Human Health”
18. Seafood Health Facts. “Omega-3 Content of Frequently Consumed Seafood Products.”
19. Sustainable Sea Food Coalition. “Commercial Fishing: Potential Environmental Issues.”
20. Natural Resources Defense Council. “Mercury Contamination in Fish.”

Are you a seafood eater? What’s your favorite type and how do you make sure it’s healthy?

When fish swim in the holodeck

Virtual reality arena for flies.
Credit: Copyright: https://strawlab.org/freemovr

Standard behavior experiments to investigate behavior in popular lab animals only incompletely mimic natural conditions. The understanding of behavior and brain function is thus limited. Virtual Reality helps in generating a more natural experimental environment but requires immobilization of the animal, disrupting sensorimotor experience and causing altered neuronal and behavioral responses. Researchers have now developed a VR system for freely moving animals to overcome most of these limitations.
From behavior to brain function

A person sees another person and depending on the context very different interactions can take place. The final outcome after the initial visual experience is a result of complex interactions of neurons in different brain regions- processes that are still very little understood. To study the neuronal basis underlying behavior, scientists have developed a broad range of techniques, most of which require either the partial or full immobilization of the animal. This restricts sensory input and feedback and ultimately changes the neuronal and behavioral responses. In addition, mimicking natural conditions in a laboratory is difficult.

A three-dimensional, reactive, computer-controlled world for moving animals

The groups of Andrew Straw at the University of Freiburg (a former IMP fellow) and Kristin Tessmar-Raible at the MFPL have now presented a system called “FreemoVR” in Nature Methods, that overcomes most of these hurdles by immersing a freely-moving animal in a reactive, three-dimensional world controlled by a computer. FreemoVR enables the experimenter to control the animal’s visual experience, while maintaining the natural feedback for its tactile senses. To do so, the scientists built behavioral arenas whose walls or floors were computer displays, including arbitrarily shaped projection surfaces. Using computer games technology, the animal could then explore the VR environment in these arenas from its own perspective while it walked, flew or swam.

“We wanted to create a holodeck for animals so that they would experience a reactive, immersive environment under computer control so that we could perform experiments that would reveal how they see objects, the environment, and other animals,” says Andrew Straw, leading in the development of FreemoVR.

Applications of FreemoVR in fish, flies and mice

To validate FreemoVR’s ability to elicit naturalistic object responses, the researchers investigated the reaction of freely swimming zebrafish and freely flying flies to a virtual upright post and tested freely walking mice, which showed to be equally afraid of heights in a real and virtual elevated maze.

Using FreemoVR, the teams found previously unnoticed behavioral differences between a wildtype and a mutant zebrafish strain, showing the sensitivity of the system. The scientists further explored the rules that govern social interactions of real zebrafish with virtual ones and found that the prospective leader fish minimizes the risk of losing followers by balancing his internal preference for a swimming direction with the social responsiveness of the subordinate fish.

Future directions

Studying and manipulating behavior in less complex organisms like fish or flies, but also more complex ones like mice and even humans is a popular way among neuroscientists to deduce information about brain function. “I am particularly excited about the possibility to mimic more complex, naturalistic environments and to test more advanced brain functions in medaka and zebrafish. It will help us to better understand brain functions and to what extent we can use these diurnal vertebrates as models for neuropsychological malfunctions,” says MFPL scientist Kristin Tessmar-Raible, who led most of the fish work.

In the future, the different teams hope to use FreemoVR to gain insights into brain function of high-level behaviors like navigation, to better understand causality in collective behavior of social groups and, in the long run, to study the mechanisms of behavior under conditions in which the brain evolved to operate.

Oil impairs ability of coral reef fish to find homes and evade predators

This is a damselfish of the Chromis species.
Credit: Jacob Johansen/Univ. of Texas at Austin

Just as one too many cocktails can lead a person to make bad choices, a few drops of oil can cause coral reef fish to make poor decisions, according to a paper published in Nature Ecology & Evolution. A team of fisheries biologists led by Jacob Johansen and Andrew Esbaugh of The University of Texas Marine Science Institute have discovered that oil impacts the higher-order thinking of coral reef fish in a way that could prove dangerous for them — and for the coral reefs where they make their home.

Examining six different species of coral reef fish, Johansen and the team found that exposure to oil consistently affected behavior in ways that put the fish at risk.

During several weeks when coral reef fish go through their juvenile stages of development, they are especially vulnerable. Even in healthy populations of reef fish, typically less than 10 percent of embryos and larvae reach adulthood. Those who survive must learn to identify friend from foe and adopt protective behaviors, such as traveling in groups, minimizing movement in open waters and swimming away quickly from danger.

In experiments, the scientists found that juvenile fish exposed to oil struggled on all these counts.

“In several different experiments, the fish exposed to oil exhibited very risky behavior, even in the presence of a predator,” said Esbaugh, an assistant professor of marine science.

The scientists also found that oil exposure negatively affected the fishes’ growth, survival and settlement behaviors (their ability to find a suitable habitat).

Oil concentrations are found in oceans worldwide, but until now little has been known about the impact of oil exposure on coral reef fish. Earlier research that explored how oil affects the physiology of fishes has demonstrated developmental heart deformities and associated cardiac functions, but this is the first study to demonstrate that oil exposure affects behavior in a way that increases predation and reduces settlement success.

The finding could be bad news for reefs, as well, since many coral reefs depend on fish to remove algae that can restrict their growth and development. Coral reef ecosystems are the oceans’ most diverse ecosystems — and the most threatened. Hundreds of millions of people depend on coral reefs and their fish for income or food, but widespread coral bleaching and overfishing threaten this way of life. The new study indicates that limiting oil-based industrial activities near reefs may be critical for reef preservation.

“Over the past 35 years, almost one-fifth of the world’s coral reefs have been lost and half of what’s remaining is either expected to disappear or be under severe threat in the next few decades,” Johansen, the lead researcher, reflected. “Still, many governments continue to allow industrial activities, including oil drilling and exploration, in sensitive reef habitats. If a spill were to occur, this study suggests there could be major consequences for the fish, for coral reefs and for people working in fisheries and tourism.”

“We used oil concentrations that are already present in many industrialized regions worldwide — concentrations that ranged from two to five parts per billion, the equivalent of a couple of drops in a swimming pool,” Johansen said.

Exposure to these oil concentrations caused higher rates both of immediate death and more latent death, in addition to the behavioral shifts and cognitive changes in coral reef fish. These results suggest that future studies of oil in sensitive environments, such as coral reefs, should account for behavior in addition to the toxic effects when trying to capture the overall ecological health of the system or make predictions about fish populations.

Solving how fish swim so well may help design underwater robots

Propeller-free robots may soon be swimming with style. A new model of how fish and other aquatic species are able to propel themselves forward without expending much energy may help create energy-efficient underwater robotsthat swim just like the real thing.

By closely studying and monitoring how fish, dolphins and other sea creatures swim, Mehdi Saadat at Harvard University and his colleagues found that many of them have remarkably similar styles that can be described with a simple model, depending on how fast and far the tail whips back and forth and the length of the animal.

Scientists previously homed in on just one parameter that relates the beat of an oscillating fish’s tail and how far it oscillates to the animal’s forward motion. But it turned out to be slightly more complicated.

Saadat and his colleagues identified a second important factor: how far the tail goes to and fro relative to the fish’s length. They found that almost all fish – and many other sea creatures – swim in a narrow optimum range of this parameter to generate thrust, with the length of each tailbeat between one and three-tenths the length of the animal.

One for all

“This gives you the right ballpark. Even for different fish shapes and gaits, if you’re in there, you are cruising at a minimum power input,” says Mattia Gazzola at the University of Illinois at Urbana-Champaign.

The researchers developed the model’s parameters by carefully monitoring trout cruising in a tank in their lab. In the tank, water flows in a circle to allow the animal to remain in one place while swimming upstream, like a fish treadmill. The team also tested a robotic system emulating a fish tail to make measurements of how much power it used as it swam.

In addition, the researchers used previously published data on a variety of other sea life, including mackerel, blacktip sharks, dolphins and killer whales, observing that they consistently swim in line with the parameters they found in trout in the lab.

“It’s amazing that so many differently shaped and different kinds of aquatic organisms fit the same general rules,” says George Lauder at Harvard University.

Saadat believes these rules could be used to aid the design of power-efficient aquatic robots. Such robots could, for example, explore the sea floor or map coral reefs without disturbing wildlife, and the US Navy is interested in stealthy robots that move without a propeller.

Why fish can’t help but eat our plastic garbage

Fish are eating our plastic waste.


Plastic isn’t food, but fish seem to eat it anyway—to the confusion of many researchers. As the 9.5 billion tons of plastic the world has produced since the 1950s makes its way into the world’s rivers, lakes, and oceans, the animal consumption of such waste has become a big problem. Yes, a lot of that plastic is tiny—roughly the size of fish food—so it’s not a stretch to think that fish are simply confusing these morsels with plankton. But the fish that are apparently attracted to plastic are usually picky eaters.

“I’ve heard both scientists and nonscientists say that there’s so much plastic out there that these animals sort of bump into it and consume it without thinking,” says Matthew Savoca, a California Sea Grant State Fellow at the National Oceanic and Atmospheric Administration (NOAA) Southwest Fisheries Science Center. “But people who know about foraging behavior and study this sort of thing know that couldn’t be further from the truth.”

Savoca co-authored a recent study in the journal Proceedings of the Royal Society B that seeks to better understand why fish chow down on literal junk food. According to their findings, it may come down to smell. The work was influenced in part by a study Savoca worked on last year on marine birds.

In that study, researchers came to a malodorous conclusion by diving into sea bird data. They discovered that birds attracted to the smell of algae—specifically a compound called dimethyl sulfide—eat a lot more plastic than species that don’t use those odor compounds to find food.

“Most of the animals that are eating plastic in the greatest quantities are what we call dietary specialists, they’re really looking for very specific types of food,” says Savoca.

The compound, which Savoca says smells like rotting seaweed, often emerges when algae cells walls die—like when zooplankton such as krill eat them. For some animals, the scent serves as a pungent signal that the plankton they love to eat are in the neighborhood.

Plastic doesn’t smell like dimethyl sulfide on its own (rotting seaweed wouldn’t sell many water bottles) but algae can infuse the material with this oceanic aroma. Algae like to attach to hard, smooth surfaces, and they float up near the air to collect sunlight—so they often hitch a ride on our garbage.

“It’s like setting up a Petri dish for algae in the ocean,” says Savoca.

In the new study, Savoca essentially wanted to ask an animal whether or not it cared for the smell of marine plastic debris. To do that, he turned to anchovies. They are known to eat plastic in the wild, and their relatively small size makes them easy to study.

It may not seem intuitive, but fish do use their sense of smell to help work their way around aqueous environments. Fish take in smells through tiny holes on their head that look like nostrils, called nares. Odors help fish avoid predators, find their way home, and, of course, search for food, just like a sense of smell helps animals on land. Anchovies generally go sniffing for zooplankton. They ignore pretty much everything else—dirt, rocks, fish parts—that they might come across.

But not plastic.

Krill like this one are what anchovies are supposed to eat.


Because Savoca and his colleagues at the University of California Davis and Aquarium of the Bay couldn’t actually ask the anchovies why they were eating plastic, they did the next best thing: They exposed the fish to five different aquatic conditions and observed their behavior.

In the first condition, the fish were exposed just to salt water, to see how they behave when there’s not much happening in the tank.

This is what the anchovies look like when there isn’t much going on food wise.

Matthew Savoca

In the second condition, Savoca and his colleagues fed the anchovies zooplankton.

“Typically, they keep a pattern of schooling that’s really consistent throughout, equal spacing, they’re positioned facing into the oncoming flow of water, that sort of thing,” says Savoca. “But when there’s food in the tank they all clump around the interesting stimulus—in this case food—and just dart back and forth trying to interact with as many different food morsels as they can.”

Savoca likens that experiment to feeding a room of hungry people pizza and watching how they behave.

In the next condition, they injected the smell of krill into the tank. They did so by soaking krill in salt water for a few hours, filtering out the plankton themselves, and injecting the remaining salt water into the tank.

“This would be like if you had a hungry person in the room and you piped in the smell of delicious pizza,” says Savoca. “The person might start looking around, they might start salivating, they might start getting antsy. That’s kind of what we saw the fish doing. They responded kind of like they were feeding, but less intensely. They clumped together, they started darting around basically searching for food that wasn’t there.”

In this case, they added the smell of krill to the water. Note how the smell really gets their attention.

Matthew Savoca

In the next experiment, researchers injected the smell of clean plastic into the tank in much the same way that they injected the krill scent. They soaked a piece of plastic in salt water for a few hours, then injected the treated salt water into the tank.

Nothing happened. The anchovies behaved the same way they did under the control condition.

Finally, Savoca and his colleagues took a piece of plastic that had been soaking in the ocean for a month and injected that odor into the tank. The anchovies acted a lot like they did when they detected the smell of krill: they clumped and darted around to try to find the source of the interesting smell.

“It was surprising how responsive these fish were to non-food odors,” says Savoca. “Sometimes in scientific studies you have to do some kind of fancy analysis to see if there was an actual effect. But anecdotally you could see, when you pumped in these certain odors, ‘oh wow, these fish are responding,’ or ‘oh no, they’re not.’”

In this case, the anchovies are exposed to the smell of plastic that has hung out in the ocean for awhile. They behave a lot like the do when they’re given the smell of krill.

Matthew Savoca

In other words, something happens to plastic in water that turns it from junk into junk food. The problem is that plastic, unlike food waste, never biodegrades. It just breaks down into smaller and smaller fragments that linger in the environment indefinitely. The lack of nutrition for hungry fish isn’t the only problem, either: plastic in the ocean also attracts a host of toxic chemicals such as polychlorinated biphenyls (PCBs), which can affect human brain development, and polycyclic aromatic hydrocarbons (PAHs), which can cause cancer in humans. Small fish eat the plastic, and then they’re eaten by humans—or they’re eaten by larger fish, and then those are consumed by humans. Increasingly, we’re eating our own toxic waste.

Savoca’s study sheds some light on why the fish are behaving this way, but if we want it to stop we have to shift our own behaviors. Savoca posits that perhaps plastic manufacturers could use biodegradable materials, or perhaps find a way to alter the surface of their products to make them less hospitable to algae. Of course, just using less plastic in general would also be a great start. Here are 12 ways you can help make that happen.