Among the many myths that swirl around food these days, fish oil consumption is a recurring one.

Over the years, fish oil has gained an unassailable reputation as a cure-all, protecting against heart disease, fending off arthritis and diabetes, and improving cognition and mood.

Today we are going to sort out the fact from fiction when it comes to fish oil…

Let’s Talk Again About Essential Fatty Acids

Fish oil falls into a separate category from cooking oils like olive and coconut oils.

Most people consume fish oil for one reason (and one reason only)–the fact it contains high levels of omega-3 fatty acids.

Let’s back up for a moment and review what we discussed in our article The Skinny on Fatty Acids.

Essential fatty acids are mandatory for our survival and must be obtained through diet. One of these essential fatty acids is omega-3, found in foods in the form of short-chain alpha-linolenic acid (ALA), or long-chain eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Do Omega-3s Really Contribute to Healthy Hearts?

Omega-3s are largely believed to prevent heart disease.

And the “Eskimo Myth”–which argues that heart disease is rare among fish-consuming Eskimos—may be at least partially responsible for fish oil’s heart-healthy reputation.

However, the Eskimo myth is really nothing more than a rumor– disproven since the 1930s.

According to a Danish study, “Eskimos have a prevalence of coronary artery disease similar to non-Eskimo populations, they have excessive mortality due to cerebrovascular strokes, their overall mortality is twice as high as that of non-Eskimo populations, and their life expectancy is approximately 10 years shorter than the Danish population.”

In fact, there is absolutely no clear evidence that omega-3 dietary supplementation reduces the risk of heart disease (including heart attack, sudden cardiac death or stroke).

A systematic review of randomized clinical trials to evaluate the effect of omega-3 on cardiovascular disease risk (through advice to eat more oily fish or taking a fish oil capsule supplement) showed that “overall, omega-3 PUFA supplementation was not associated with a lower risk of all-case mortality, cardiac death, sudden death, myocardial infarction, or stroke based on relative and absolute measures of association.”

Another study looked at the potential benefit of long-chain omega-3 supplementation for those people who already had cardiovascular disease and “showed insufficient evidence of a secondary preventive effect of omega-3 fatty acid supplements against overall cardiovascular events among patients with a history of cardiovascular disease.”

And even the FDA points to inconclusive evidence, “Supportive, but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease.

The Real Reason You Need Omega-3s

While omega-3s impact on healthy hearts is inconclusive, their positive effect on brain health holds up.

Because of its predominance in the brain, DHA plays a crucial role in mental development in infants, brain, and nervous system function as well as in behavioral and mood disorders in both children and adults.

The World Health Organization (WHO) and the European Food Safety Authority (EFSA) both recommend we get at least 0.5% of our daily calories from the short-chain omega-3 alpha-linolenic acid (ALA), which is converted to DHA in our bodies.

If you are wondering what that means exactly, 0.5% translates into about 9-10 calories a day. (In other words, a little goes a long way.)

Omega 3s and 6s—It’s All About the Ratio

As we discussed in our essential fatty acids series, there are 3 kinds of dietary fats: monounsaturated (MUFA), polyunsaturated (PUFA) and saturated fatty acids (SFA).

The only ESSENTIAL fatty acids are PUFAs, i.e. omega-3s and omega-6s.

But it is crucial to understand that omega-3 and omega-6 must be consumed in the RIGHT ratio. In fact, the ratio of omega-3 to omega-6 is more important than the amount of omega-3 alone.

Obsessing about getting enough omega-3 fatty acids without substantially reducing the amount of omega-6 fatty acids taken in through added oils and fats is futile. That is because omega-3s positive effects can be canceled out if you are consuming high amounts of omega-6 fatty acids.

The American diet is filled with omega-6 rich food mainly due to the presence of safflower, sunflower, corn, and soybean oils.

And eating excessive amounts of omega-6 has the exact same effect as consuming saturated fats; it leads to atherosclerosis and increases the risk of cardiovascular disease.

So Where Should We Get Our Omega-3s From?

Quite frankly, fish may be the least healthful source of omega-3s.

That is because fish, especially fatty fish, has been shown to be a major dietary source of Polychlorinated Biphenyls (PCBs) with farmed salmon having the highest total number of toxins.

But there is more bad news about fish and fish oils.

Just one serving of fish a week may increase your risk of developing type 2 diabetes and both fish and fish oils may lead to suppression of the immune system.

A much better way to get omega-3s is through a whole food plant-based diet.

ALA-rich foods include walnuts, flaxseeds, and chia seeds. And it is really so simple; all it takes is one tablespoon of ground flaxseeds to meet your daily requirement.

But if you are looking for a safe source of preformed DHA, to get the benefits of omega-3s without the pollutants, look for an algae-derived DHA supplement. Algal DHA supplementation (200-250 mg daily) is especially important for pregnant and breastfeeding women.

In the End…

To maintain the right amount (and ratio) of essential fatty acids, you must:

  • Eliminate omega-6-rich fats and oils.
  • Consume an appropriate amount of omega-3s (0.5% of your daily calories).
  • Get your omega-3s from plant sources.

And to reap the beautiful brain benefits of omega-3s, just skip the fish oil and stick to a whole food, plant-based diet.

Rosane Oliveira, DVM, PhD

Rosane Oliveira, DVM, PhD

President & CEO, Plant-Based Life Foundation | Dr. Rosane Oliveira combines a lifelong passion for nutrition with 25 years of genetics research to create programs that help people develop healthy habits on their journey towards a more plant-based lifestyle. She is a Visiting Clinical Professor in Public Health Sciences and was the founding director of the first Integrative Medicine program at the UC Davis School of Medicine. She completed her postgraduate studies in Brazil and did her postdoctoral training in immunogenetics and functional genomics at the University of Illinois at Urbana-Champaign.