Fish Oil

5 health benefits of cod liver oil

Five Benefits of Fish Oil Supplements for Bodybuilding

Fish oil. You’ve probably heard of it. You may even supplement with it. But are you aware of the many benefits that it provides? Let’s take a look at some of the lesser-known benefits of fish oil that may help you reach your bodybuilding goals.

What is Fish Oil, Anyway?

Fish oil is exactly that—it’s the oil extracted from the tissue of fish. When you consume oily fish—such as salmon, albacore tuna, lake trout, anchovies, and mackerel—you’re consuming fish oil. And that’s a good thing. The American Heart Association recommends eating two servings of fatty fish per week. That’s because fish oil is rich in omega-3 fatty acids, or the heart-healthy fats our bodies need.

Other foods also contain omega-3 fatty acids, but the omega-3s in fish oil are the most bio-available kind. So while you can get omega-3s from foods like flaxseed, walnuts, and soy, you may want to consider supplementing with fish oil if you avoid eating fish itself. Even if you do eat fish, you may want additional omega-3s in your diet. To determine the specific amount for you based on your personal health and fitness goals, your best bet is to consult a nutritionist.

Five Benefits of Fish Oil for Bodybuilders

Fish oil is a popular dietary supplement for good reason. It’s thought to have a positive impact on heart, brain, eye, and skin health. But the benefits of fish oil and fish oil supplements also extend beyond general health to bodybuilding. Here are five important benefits of fish oil in bodybuilding.

1) Improve Body Composition

Want to gain lean muscle and lose fat? Fish oil may be a part of the answer. This study in the Journal of the International Society of Sports Nutrition shows that supplementation with fish oil, as compared with a placebo of safflower oil, significantly increased lean muscle mass and decreased fat mass.

2) Boost Metabolism

Studies (like this one) show a correlation between fish oil supplementation and increased metabolism. Granted, this is a bit of a chicken-and-egg situation—it’s not certain whether metabolism increased because of the fish oil supplementation, or because of the related increase in lean muscle mass (higher muscle mass typically correlates to higher metabolism). Regardless, the result is a positive one for anyone looking to tone up and improve their body composition.

3) Increase Protein Synthesis

Omega-3 fatty acids have been shown to help promote muscle protein synthesis, aiding the conversion of dietary protein into muscle-building fuel. This study out of Washington University shows how omega-3s help enhance the body’s muscle-building response—which means fish oil can help with bodybuilding, as well as recovery from any athletic endeavor.

4) Enhance Performance

Another interesting benefit of fish oil is that it’s been shown to reduce heart rate and oxygen consumption during exercise. One study of a group of highly fit cyclists showed that fish oil supplementation reduced whole-body and oxygen demand during exercise, without a decrease in performance. Bottom line: fish oil may allow you to “do the work” with less stress to your body—and gain an advantage over your competitors.

5) Aid Recovery

Fish oil is often used to help reduce joint pain and stiffness in people with rheumatoid arthritis. That’s because it has an anti-inflammatory effect—which is beneficial to bodybuilders and other athletes alike. This study shows a specific relationship between omega-3 supplementation and reduced inflammation following strength training. By decreasing DOMS (delayed onset muscle soreness), fish oil can help you recover better and get ready to train hard again sooner.

Ready to try fish oil? The studies mentioned above certainly point to positive potential benefits of fish oil supplements for bodybuilders. Again, as with any dietary planning, we recommend consulting a nutritionist to determine your specific needs, based on your health and fitness goals. If you consume a lot of oily fish already, you may not need additional omega-3 supplementation. But if you don’t eat fish, it’s possible that adding fish oil supplements to your nutrition plan may help boost your bodybuilding efforts through improved body composition, performance, and recovery.

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Benefits of fish oil: 9 backed by science

See more Disclaimer If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

There are a couple of supplements that get a lot of lip service: multivitamins are a given, prenatal vitamins for pregnant women, and fish oil.

If you’re not especially fond of fatty fish, it can sound more appealing to take the prenatal vitamins—even if you’re a man—than reach for a supplement like cod liver oil (please don’t). It’s worth grabbing a supplement if your fish intake isn’t up to par; after all, the nutrients found in them aren’t called essential fatty acids for nothing.

Fish oil is made up of omega-3 fatty acids and other fats. These supplements are made from fatty tissues of oily fish, and occasionally fish livers. The main health-boosting types of omega-3s you’ll find in fish oil are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Algae oil can offer a vegetarian version of EPA and DHA, while most other plants make their own omega-3 called alpha-linolenic acid (ALA). While all three types of omega-3s can have health benefits, more research has been done on EPA and DHA.

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Benefits of fish oil

Here’s the thing: not everyone likes fatty fish. But you can’t ignore all the health-boosting benefits essential fatty acids have in our bodies—more on that in a second.

For people who can’t stomach fish, omega-3 fatty acid supplements are likely a must. These polyunsaturated fatty acids cannot be made by the body and need to be consumed through diet or supplements. Here are the health benefits that earn fish oil a place in your cabinet, right next to your multivitamin or testosterone supplement.

While there have been many studies that look into the health benefits of fish oil (as discussed below), some have only been conducted in small groups or in people with specific health conditions. As a result, not all of the benefits described below may be true for everybody taking fish oil.

1. Supports heart health

Heart disease is the leading cause of death for both men and women in America. And more than half of those deaths in 2015 were men. It can feel overwhelming to overhaul your heart health, but getting started can be as easy as regularly supplementing with fish oil (CDC, 2019).

Fish oil supplements may, in fact, reduce multiple factors that contribute to the risk of heart disease, including modestly increasing “good” cholesterol (HDL), supporting lower triglycerides, and reducing blood pressure in people with hypertension or high blood pressure (Minihane, 2016).

It also appears to support cardiovascular health and lower your risk of cardiovascular disease by both stabilizing plaque in arteries that already exist (making it safer) and widening arteries as blood flows. Though many of these effects may lower your risk of heart attack, there is no evidence that omega-3s can prevent them (Wang, 2012).

2. Lowers blood pressure

We mentioned this already since it ties back to your overall cardiovascular health and risk of cardiovascular events, but fish oil supports healthy blood pressure.

In fact, a meta-analysis found that omega-3 fatty acids EPA and DHA are effective at reducing both systolic blood pressure (the pressure in your arteries when your heart muscle contracts and diastolic blood pressure, the pressure in your arteries between beats (Miller, 2014).

However, an early study found that this effect is strongest in patients already suffering from hypertension or atherosclerosis, a disease that causes plaque to build up in your arteries. The American Heart Association advises that patients eat a diet rich in fish to manage blood pressure, along with other lifestyle modifications (AHA, 2016; Morris, 1993).

3. Help treat mental disorders and depression

Jokes about being a “fat head” aside, our brains are indeed mostly fat. Nearly 60% of your brain mass is fat, in fact, and a vast majority of this is comprised of omega-3 fatty acids. It’s no wonder then that you need omega-3s for normal brain function and mental health, including mood and cognition (Bazinet, 2014).

Many studies have found connections between mental disorders, such as schizophrenia and depression, and deficiency in fatty acids. In the case of major depression, it’s believed this has to do with inflammation in the body and the role of fatty acids in alleviating it (or not if they’re missing).

Some studies have also shown that omega-3 supplementation can diminish symptoms of schizophrenia and bipolar disorder (Amminger, 2015).

4. Helps with weight loss

Weight loss isn’t all about aesthetics; for many people, losing weight can significantly increase their overall health and lower the risk of obesity-related illnesses like heart disease, cancer, and type 2 diabetes.

Studies are a bit torn about the connection between fatty acid intake and weight loss. One review of studies that didn’t observe a change on the scale did note a decrease in waist circumference and waist-to-hip ratio. Other studies have found that fish oil supplements can help reduce weight when combined with a sensible diet and exercise regimen (Du, 2015).

5. Supports eye health

This is another area where researchers don’t always see eye to eye. Your eyes, like your brain, rely on fats. And it does seem that those who suffer from a lack of omega-3 fat have a higher risk of eye diseases such as macular degeneration (Merle, 2014).

This is especially important for older adults who may suffer from age-related macular degeneration (AMD). But whether supplements can help with this isn’t entirely clear. One study found that eating fish twice a week did lower the risk of AMD progressing, but it was dependent on participants having the right balance between omega-3s and 6s (Seddon, 2003).

Supplementing with krill oil, which is a mostly phospholipid form of omega-3 supplements (this refers to the molecules DHA and EPA bind to), also improved symptoms of dry eye in study participants compared to a placebo (Deinema, 2017).

However, a review concluded that improvements in dry eye in studies that tested supplements weren’t clinically significant (Ton, 2018).

6. Reduces inflammation

Not all inflammation is bad. We need inflammation to help fight off infection. But some kinds of inflammation are risk factors for serious conditions like diabetes, heart disease, depression, and obesity.

Since omega-3 fish oil boasts anti-inflammatory properties, it can help treat conditions associated with chronic inflammation, such as rheumatoid arthritis. In fact, studies have observed the ability of these fatty acids to help specifically with joint issues like pain and stiffness.

7. May help children with ADHD

Fatty acids are essential for the brain, and not just when it’s fully developed. Infants who don’t get enough of these nutrients are at a higher risk of developing mental health conditions such as schizophrenia and attention deficit hyperactivity disorder (ADHD).

Luckily, symptoms of ADHD in children who were short on the fatty acids as infants can be improved with supplements. One study found that EPA, specifically in high doses, was most helpful in easing symptoms (Bloch, 2011).

8. Supports cognitive function

As you age, your risk for Alzheimer’s disease increases, and brain function slows.

Studies show that fatty fish consumption may slow cognitive decline. And it continues to be important, as the amount of fish eaten by older adults appears to be tied to better mental performance—and the effects are relative to the dose (van Gelder, 2007).

Although a small study showed that five weeks of taking fish oil supplements offered benefits in mental performance, not all researchers are convinced. Other studies have found no statistically significant connection between omega-3 fish oil supplements and improved mental function or slowed cognitive decline (Chew, 2015; Nilsson, 2012).

9. Alleviate asthma symptoms

Asthma is another condition tied to inflammation, in this case, in the lungs. Swelling of the lungs causes shortness of breath we think of as characteristic of this condition.

One study found that supplementing with fish oil helped ease symptoms in children with asthma. But the effects of fish oil on asthma can also potentially be preventative.

Another looked at the likelihood of a woman’s child having asthma if she supplemented with olive oil versus fish oil in the late stages of pregnancy. Fish oil was much more likely to decrease a child’s chance of developing the condition by the age of 16 (Olsen, 2008).

How to get enough omega-3 fatty acids

We know that fish can be a little too, well, fishy for some people to stomach. But if you are open to eating oily types of fish like sardines, mackerel, and anchovies, aim for 1-2 servings per week.

This is a moderate weekly intake that balances your need for omega-3s with the risk associated with taking in too much mercury. If upping your intake of fatty fish is simply out of the question, it’s probably time to consider an omega-3 supplement.

If you’re following a vegan or vegetarian diet, you’ll want to supplement with alpha-linolenic acid, a type of omega-3 fat found in plants or algae oil. Flaxseed oil is a good option for meeting your daily needs.

Guidelines for recommended dosage differ from group to group, but the World Health Organization (WHO) advises 200–500 mg of combined EPA and DHA. You may see this in grams on the packaging, in which case, choose dietary supplements that offer between 0.2 and 0.5 g of the two fatty acids (WHO, n.d.).

High doses should only be taken under the supervision of a medical professional. And side effects of fish oil capsules may include a bloody nose, heartburn, nausea, loose stools, bad breath, and belching. The most common side effect is fishy burps, but this effect can be diminished by keeping your supplement in the fridge.

What to look for in a fish oil supplement

When choosing a fish oil supplement, you’ll quickly notice that they come in many different forms.

Although your body has a hard time absorbing and using ethyl esters, you can pick up pretty much any other kind. These include free fatty acids, phospholipids, triglycerides, or reformed triglycerides.

Although several prescription omega-3 formulas have been approved by the U.S. Food and Drug Administration (FDA) to lower triglycerides, over-the-counter supplements are not regulated by the FDA. That’s why it’s important to buy from a brand you trust or look for the seal of purity from the Global Organization for EPA and DHA Omega-3s (GOED).

Fish oil can also go bad. Try to find one that includes an antioxidant like vitamin E in the formulation to prevent this. You can also help avoid your fish oil capsules going rancid by keeping them away from sunlight and also choosing one packaged in darkly colored material to keep light out.

5 health benefits of cod liver oil

Read on to discover what gives cod liver oil its health-promoting reputation, plus whether a supplement is really the best way to get these health benefits.

Cod liver oil is renowned as a nutrient-dense source of vitamins and essential fatty acids. As the name suggests, it’s derived from the liver of the fish and is available as a liquid or capsule supplement. It's different in composition to fish oil, which is extracted from the body of oily varieties of fish.

Interested in trying our FREE 7-day healthy diet plan? Click here and choose between our meat eaters, vegetarian or vegan meal plans.

Discover our full range of health benefit guides. You can also explore further benefits of dietary fats and omega-3 fatty acids.

Nutritional benefits of cod liver oil

A 1,000mg serving provides approximately:

144mg EPA

107mg DHA

800µg vitamin A

10µg vitamin D

The composition of cod liver oil varies to that of fish oil – both are excellent sources of omega-3 fatty acids, but in different ratios. Cod liver oil also provides naturally occurring vitamin A and vitamin D.

Top 5 health benefits of cod liver oil

1. Supports heart health

The star ingredient in cod liver oil is omega-3 fatty acid, a polyunsaturated fat. It's known as an essential fatty acid because the human body is unable to make it, so it’s vital that we get it from our diets. The omega-3 fatty acid from fish can be broken down into two different types – eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) – which offer many health benefits, together and individually. They are known to be heart-healthy, with studies reporting that omega-3 fatty acids may help reduce triglycerides, increase healthier HDL cholesterol and lower blood pressure.

While most of the research suggests that consuming fish oil such as cod liver oil may reduce certain factors associated with heart disease, more evidence is required to confirm whether fish oil has a preventative effect. Nevertheless, current UK dietary advice remains the same: to help prevent heart disease, the NHS recommends eating two portions of fish per week, one of which should be an oily variety such as salmon, mackerel or trout.

2. Mood-boosting

Omega-3 fatty acids, specifically DHA, are important brain nutrients. Studies have shown that omega-3 fatty acid may play a role in lowering anxiety and improving cognitive function. In a large study of 21,835 participants, those who regularly consumed cod liver oil were shown to have fewer depressive symptoms. Furthermore, a clinical trial of medical students showed that supplementation of omega-3 fatty acids lowered inflammation and resulted in less anxiety over a 12-week period.

With this said, several similar studies found little or no effect of fish oils on mood, which suggests more research is required to fully understand the mechanisms behind these associations.

3. May support improved memory

There has been some positive research into the link between omega-3 fatty acids and memory. The Nutrition Journal published a paper that suggested that five weeks of daily omega-3 fatty acid intake had the potential to improve cognitive function in those aged 51-72 years old. In 2018, a systematic review found that omega-3 fatty acid supplementation generally correlated with improvements in cognition, especially in those with a low baseline level of fatty acids in their system.

4. Supports bone health

Cod liver oil is a great source of vitamin D, which is required to help the body absorb calcium, a vital bone mineral – from the gut. As such, adequate vitamin D and efficient calcium utilisation may help to reduce age-related bone loss.

5. May be beneficial for rheumatoid arthritis

Thanks to the anti-inflammatory effects of omega-3 fatty acid and vitamin D, it appears that cod liver oil may be of benefit to those with rheumatoid arthritis, helping reduce pain and potentially minimising the need for certain medications.

A study looking at the eating habits of 32,000 middle-aged women found that those who ate one or more portions of oily fish per week were 29% less likely to develop the rheumatoid arthritis than those who never or only rarely ate oily fish.

Is cod liver oil safe for everyone?

The World Health Organisation recommends eating one or two portions of oily fish a week, equivalent to 200-500mg of EPA and DHA. Those with an allergy to fish or who follow a vegetarian or vegan diet should look to alternative plant-based sources of these essential fatty acids.

As a supplement, omega-3 fatty acid is generally regarded as safe for most people, when taken in low doses (approximately 3g total fish oil per day or less). If you are considering taking a new supplement, discuss this with your health practitioner first, especially if you are taking prescription medication.

Supplements provide a concentrated and often more convenient dose of omega-3 fatty acid for those who may not be able to sufficiently cover their needs through diet. With that said, it is always preferable to attain nutrition through food and choose supplements only when additional support is needed. Most cod liver oil capsules also contain vitamin D and A, so make sure that you’re not taking any other supplements such as a multivitamin, or you may exceed the recommended amounts each day.

It should be noted that the NHS advises against taking cod liver oil during pregnancy because the high level of vitamin A may cause risk to the developing foetus. It is best to speak to your doctor about your options if you are pregnant or looking to conceive.

If you do decide to take a supplement, choose a product from a reputable company that tests its product for purity, because fish oils may contain contaminants such as mercury and dioxins.

Try some omega-3 rich recipes:

Grilled mackerel with soy, lime & ginger

20-minute rice supper

Herb-crusted haddock

Tandoori trout

Tuna steaks with cucumber relish

Baked sea bass with lemongrass & ginger

Horseradish baked salmon

South Indian fish curry with chickpeas

Enjoyed this? Now read:

The health benefits of salmon

Our favourite healthy salmon recipes

More healthy fish recipes

This article was last reviewed on 26th November 2021 by Kerry Torrens.

Nicola Shubrook is a nutritional therapist and works with both private clients and the corporate sector. She is an accredited member of the British Association for Applied Nutrition and Nutritional Therapy (BANT) and the Complementary & Natural Healthcare Council (CNHC). Find out more at


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Eric Carter