How beneficial are fish oil supplements?

Cardiologists and general practitioners are getting asked a common question by many patients, “Should I be taking a fish oil supplement?”  With heart disease as the leading cause of death in the U.S. and the fact not everyone likes to eat fish, this is a legitimate questions to be inquiring about.

Millions of Americans take an amber-colored capsule of fish oil every day.  The promise, the lure of strong marketing claims touting  “may reduce coronary heart disease,” catch our eye drawing us into the belief the fate of whether we develop heart disease or not, depends on us swallowing fish oil daily.

A brief history of fish oil

Over 50 years ago, scientists noticed that people who consumed lots of fatty fish – salmon, herring, mackerel, tuna, and sardines – had low rates of heart disease.  Fatty fish, the kind that live in cold waters, are rich in two key omega-3 fatty acids known as DHA and EPA. Some plants are rich in another type of omega-3 fatty acid called ALA, which include flaxseed, chia seeds, walnuts, pumpkin seeds, and canola oil.

These unique fats have a number of biological effects that may benefit the cardiovascular system.  For example, omega-3 fatty acids may help ease inflammation, possibly prevent the formation of dangerous clots in the bloodstream, and may reduce deadly heart arrhythmias.

It was during the 1980’s that omega-3 fish oil supplements begun showing up in stores for sale. By 2012, they were the most popular natural product used by adults in the U.S.  In fact, in the late 1990’s, a large Italian study called the GISSI study, showed that heart attack survivors randomly assigned to polyunsaturated fatty acids (omega-3 or “fish oil”) supplements had a reduction in death, heart attack, and stroke compared to those who did not take the supplement. Because of this study, the American Heart Association started recommending fish oil supplements to patients with heart disease.  Doctors like cardiologists, started to do the same. Soon after, fish oil supplements were also being recommended for people without heart disease.  Fish oil supplements were the “star” supplement and “miracle cure” everyone believed they needed to be taking.

Fish oil supplements were such a big business that Americans were spending more than $1 billion a year on over-the-counter fish oil.  Even food companies wanted their marketing share and did so by adding it to milk, yogurt, cereal, chocolate, cookies, juice, and hundreds of other foods.

What do scientific studies say?

The question has always been do fish oil supplements actually deliver on its promise of preventing and protecting individuals from heart disease?  Medical professionals like to pride themselves on “scientific evidence-based” information. And that’s a good thing. What is recommended to patients should and must be based on vigorously tested, well-designed studies where proven and reproducible benefits have been demonstrated.

When the evidence from such studies is mostly pointing to the same conclusions, that’s when evidenced-based medicine works well. But what about when the evidence found is mixed?  In other words, what is some studies show a benefit but others do not?

When this situation happens, a common strategy used is to combine several studies where mixed results have occurred, into one study called a meta-analysis. The notion here is that by combining the data, it may help to conclude which answer is correct.

When a closer look was taken at the true effectiveness of fish oil supplements on heart disease, recent studies have had mixed results. One study found that EPA and DHA had a small benefit and may be associated with reducing heart disease risk.  However, a second study of over 75,000 individuals found omega-3 fatty acids to have no significant association with fatal or nonfatal coronary heart disease or any major vascular event. It also stated it provided no support for current recommendations for the use of fish oil supplements even in people with a history of heart disease.

What’s the answer – take fish oil supplements or not?

It appears that from results of these recent studies, the benefit of taking a supplement of fish oil is small.  Even the American Heart Association has issued an updated advisory about fish oil supplements and their cardiovascular benefits by stating: “Fish oil supplements may slightly lower the risk of dying of heart failure or after a recent heart attack. But they do not prevent heart disease.”

Here are suggestions on what to do:

·      The first thing to do is ask your personal physician of their opinion.   If your doctor prescribed them, follow their advice but have a conversation with them sharing your concerns and questions.

·      If you are taking them on your own - without consulting with your physician first - believing they will reduce your risk of heart disease, it may be time to rethink your decision. If you do not like fish and have been using fish oil supplements to replace them, you can still get omega-3 fatty acids from other food sources such as ground flaxseed or flaxseed oil, chia seeds, walnuts, canola oil, and soy oil. One to two servings a day can help you avoid a deficiency of omega-3s.

·      If you do like fish, this will be the very best way to obtain omega-3 fatty acids and will be your best strategy for doing so. Your body likes it best when you consume omega-3s from actual food sources first. Not only do fatty fish supply a rich source of omega-3s, they also have an entire symphony of vitamins, minerals, and other important nutrients that a fish oil supplement will not supply. It is recommended to consume fatty fish at least twice a week. This same philosophy holds true of other foods.

·      Taking even a handful of supplements is no substitute for the wealth of nutrients you get from eating fruits, vegetables, and whole grains - in other words, eat real food.  

·      If you do decide to take a fish oil supplement, find a high-quality supplement manufactured from a reputable company.