Do Omega-3 Supplements Really Work?

Do Omega-3 Supplements Really Work?

August 07, 2020 7 min read

Omega-3 supplements overflowing in a bowl

At a glance

There has been a lot of debate in the medical and scientific communities about whether or not omega-3 supplementation has an impact on heart, brain and overall body health. It’s well-documented that omega-3 fatty acids from food are beneficial for the heart, but until November of 2018, there were no strong research studies conducted on supplementation itself.

While omega-3 supplements are not going to help everyone, there is now a strong body of evidence showing that people who do not get enough omega-3 through their diets can significantly reduce their chances of a severe cardiac event with regular consumption of omega-3 supplements.

There are several types of omega-3 supplements on the market, and all vary a bit in efficacy and potency: Fish oil, krill oil and vegetarian omega-3 supplements all provide different types of fatty acids with different levels of efficiency.

The omega-3 supplement market

Supplement companies have a vested interest in getting people to buy into the fact that supplements are effective. Persuasion comes in many forms, though, and just because you can present a compelling argument doesn’t mean you’ve made a quality product. Since supplements are considered food, the FDA doesn’t regulate or evaluate the claims made by companies, and it leaves the door open for spurious claims, inferior products and dishonesty among manufacturers.

On the other hand, it’s also reasonable — and important — to question pharmaceutically incentivized doctors who refute the efficacy of supplements.

This makes the research part of our job really important. While we don’t want to discount small studies that show promising, emerging evidence, we also don’t want to be misleading. There are no magic pills. Health and well-being is a multi-faceted process, and supplements can be an important part of that. Omega-3s fatty acids are very well-studied and researched. There is a huge amount of evidence(1) that shows the benefits of omega-3s in the diet, usually obtained from eating certain kinds of fish and nuts. But despite this, there has historically been very little evidence to support the fact that omega 3supplements actually work. This changed in November of 2018(2).

What are omega-3 fatty acids?

Omega-3 acids are a type of polyunsaturated fat. There are three main omega 3 fatty acids: ALA (alpha-linolenic acid), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Many supplements help the body replenish or restore enzymes, proteins and acids that it already makes. However your body does not make “essential” omega-3 acids on its own, so you have to get them from the food you eat and the supplements you take.

Together, the three main omega-3s are important components of your cellular structure, eye and brain function, and have a role in the healthy function of your cardiovascular, respiratory and endocrine systems.

The mechanism of omega-3s

The term “essential” acids refers to the body’s inability to create them on their own; essential fatty acids must come from foods you eat. Consuming supplements or food with ALA alone (alpha-linolenic acid) only results in a modest conversion to EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). So the best way to make sure you can benefit from omega-3 fatty acids is to consume foods or supplements high in EPA and DHA.

With regard to cellular structure, omega-3s can change the shape and function of membranes. This affects the way in which the cell reacts to other cells and the body’s inflammatory responses. It is this change in cellular structure and communication that is responsible for a lot of the omega-3 benefits.

Since the cell membrane is made up of about 20% fatty acids, a well-nourished cell can provide a more open (or more closed, depending on the cell’s needs) pathway for electrical signals to pass from one cell to another. In essence, the ability for cells to be more changeable and flexible help ensure the communication network in the body flows smoothly.

What are the benefits of omega-3?

Studies have shown omega-3s to be beneficial for everything from arthritis(3) to cognitive function(4), but by far the main body of research focuses on the impact omega-3s have on cholesterol(5) and overall heart health.

While eating fatty fish, nuts and certain plants can provide omega-3 acids, it’s important to note that omega-3 intake alone isn’t an all-encompassing fix for high cholesterol or coronary issues.

Man out for a run on a trail outside


What factors impact cholesterol levels?

Getting enough omega-3s in your diet is important and has been shown to help cholesterol. But other factors have a strong influence on cholesterol levels and heart health as well. Taking an omega-3 supplement will help. But making lifestyle changes like increasing your physical activity, quitting smoking, losing weight and moderating alcohol consumption can make a significant impact, especially when combined with an omega-3 supplement and/or dietary intake of omega-3 fatty acids(6).

What are the best food sources of omega-3?

Eating foods high in omega-3 is a biologically effective way to get the necessary fatty acids into your body. Since your body can’t convert much ALA into EPA and DHA, foods and supplements high in EPA and DHA are the only reasonable way to get those essential nutrients.

Fish and seafood are the go-to sources for most dietary omega-3s. This is especially true for cold-water fatty fish like tuna, sardines, mackerel and salmon. You can also get lots of omega-3s from nuts and seeds (chia, flax, walnuts, etc.) and in plant oils, like flaxseed oil, soybean oil and canola oil.

Another method people have used for years to increase their intake of omega-3s is through the use of supplements.

Omega 3 foods, fish, nuts, seeds and oils


Do omega-3 supplements really work?

For years, omega-3 supplements like fish oil have been revered by consumers for their ability to lower cholesterol, improve brain function and protect the heart. But despite numerous studies and agreement that omega-3 in the diet plays a vital role in health, there is very limited evidence that shows that omega-3 supplements actually work. However, an increasing body of work, including two extremely important recent studies, has started to change that.

VITAL study

The VITAL (VITamin D and Omega-3 TriAL) Study was a very large study conducted over several years with 25,871 adults. It is an ongoing study, with initial results posted in November of 2018. is the largest study of its kind to study omega-3 supplementation (vs. food-derived omega-3s). The study found that omega-3s did reduce the risk of heart attack by 28%, and it also reduced the risk of all major cardiovascular events by 19% of people who didn’t already regularly consume fish (regularly=1.5 servings or more).


While the VITAL study focused on average, healthy people, the REDUCE-IT (Reduction of Cardiovascular Events with EPA-Intervention Trial) studied 8,000 middle-aged and older adults with elevated triglyceride levels and were at risk for a cardiovascular event (heart attack, stroke, etc.) or had already experienced an event.

The study found that omega-3 supplements reduce the chance of a cardiovascular event (including death) by25%.

Omega 3 heart studies - VITAL and REDUCE-IT

Both of these studies were presented in an article by Harvard Medical School (7), which generally takes a skeptical lean when it comes to supplements. But legitimate, large and well-conducted studies like VITAL and REDUCE-IT are the kinds of studies needed to propel supplement research into the future.

Which omega-3 supplement is best?

The best omega-3 supplement for you is dependent on your needs. High-dose omega-3 supplements might be better for those who are at risk for cardiovascular events, whereas a smaller dose might more tolerable and effective for healthy people who just aren’t able to eat enough fish in their diets. It’s also important to consider supplements that have both EPA and DHA in them to reap the maximum spectrum of health benefits.

Fish oil

Traditionally, an omega-3 supplement will come in the form of fish oil. Fish oil is exactly what it sounds like — oil from the tissue of fish. Even though (until recently) there was limited evidence that omega-3 supplements were a reasonable substitute for actual dietary omega-3s, many people take omega-3 fish oil supplements for health. This is helpful for people who just don’t like the taste of fish (even though a lot of fish oils have a fishy aftertaste).

Cod liver oil

Cod liver oil(8) by the spoonful may no longer be ubiquitous in today’s world, but cod liver oil supplements are still popular. CLO varies slightly from fish oil in that it comes from the liver of the fish, but it also has a high concentration of vitamin A and D in it. Cod liver oil is most bioavailable (absorbed by the body) in liquid form, and it’s hard to get past the taste for many people.

Vegetarian omega-3 supplements

There are a lot of omega-3s without fish on the market, including flaxseed oil, perilla oil and algal oil. While these supplements do provide ALA, they are different from marine-based omega-3s and do not provide the beneficial EPA and DHA fatty acids. Algal oil is probably the most researched of the vegetarian omega-3 supplements, whereas perilla oil has very little supporting evidence. As vegetarian and vegan omega-3 options become more popular, more variants and larger studies will likely be conducted.

Krill oil

Krill oil is not new, but its surge of popularity is fairly recent. Krill oil comes from the oil of small, shrimp-like crustaceans called krill. Because it doesn’t come from fish, krill oil solves a problem that a lot of people have with fish oil supplements, which is its fishy aftertaste. Krill oil has many of the same benefits of fish oil, but may be more potent(9) and allow for smaller doses.

Another benefit of krill oil is that its DHA and EPA content is in the form of phospholipids(10), which means it generally has a higher bioavailability than fish oil.

In summary

Omega-3 fatty acids have been taken for heart, brain, eye health and more for a long time. There is a large body of research that demonstrates the importance of omega-3s in the diet from fish, nuts and oils. But up until recently, there weren’t any large, well-conducted studies on the use of omega-3 supplements. The VITAL and REDUCE-IT studies changed the narrative on supplements a bit, and now it’s more important to considerwhich supplement to take, rather than wonderif omega-3 supplements work in the first place.

For people who don’t like to eat fish, or for people who are at risk for heart attack and other cardiovascular events, omega-3 supplements can be very beneficial. And while vegetarian omega-3 supplements do provide some ALA, they often lack in EPA and DHA. Fish oil is standard when people consider omega-3 supplements, but krill oil is less fishy tasting, is more potent in small doses and can be more easily absorbed by the body.

Omega-3 fatty acids are an important part of any diet, but our bodies can’t produce all of the essential omega-3 fats on their own. So incorporating fish oil, krill oil, fatty cold-water fish, nuts and oils into the diet is important for overall health and well-being.

Seth Garland - Content Writer, Physician's Choice

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