A fish fairy tale or a good catch?


February 5, 2019 – If you take a handful of supplements every morning, chances are fish oil may be among them.

The global value of the fish oil market is projected to exceed $ 4 billion by 2022. Enthusiasts say it can help with age-related macular degeneration, rheumatoid arthritis pain, high cholesterol, asthma, depression, ADHD, heart disease, and even help you get gorgeous hair.

If this all sounds too good to be true, then you know. …

But before you throw away your fish oil like 3 day old fish, do some research on the facts. It can have some benefits for your heart, joints, and brain. But there are reservations.

What is fish oil?

Doctors and scientists first became aware of fish oil when research found that cultures that ate more fish – Scandinavians and Inuit, for example – had fewer heart disease. Many types of fish, including salmon, mackerel, herring, lake trout, sardines, and albacore tuna, contain omega-3 fatty acids – a healthy type of fat. Two of the most important omega-3 fatty acids in fish are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The researchers wanted to know whether taking fish oil directly – without eating fish – could help the heart.

“Results are very mixed in clinical trials,” said JL Mehta, MD, PhD, cardiologist and professor at the University of Arkansas for medical sciences at Little Rock. “Some show advantages. Not many. “

Why the mixed reviews?

Early tests showed that fish oil helped the heart in many ways, but researchers scratched their heads when newer studies didn’t come up with the same results.

“That may be because there are so many drugs that are now being used to treat high-risk patients. A very large percentage are taking aspirin, statins, beta blockers, ACE inhibitors, and this can obscure the role of a dietary supplement like omega-3s, “says JoAnn Manson, MD, director of preventive medicine at Brigham and Women’s Hospital in Boston.

Also, Westerners may now eat more fish than they used to because they heard it was good for them, so supplementing them wouldn’t help.

Different studies also use different fish oil doses and formulations – regardless of whether they are equal parts EPA and DHA or are heavier than the others.

The proof of fish oil

If you’ve had a heart attack or are at high risk of having one …

Large prescription doses of pure EPA – not the kind you buy off the shelf at drugstores – can help the hearts of people who have certain conditions that make heart problems more likely. Prescription fish oils lower triglycerides – a type of fat that circulates in the bloodstream. A recent study showed that 4 grams of pure EPA per day for 5 years significantly reduced the risk of heart attack, stroke, bypass, chest pain, and death from sudden cardiac arrest during this time.

However, it’s worth noting that the people who saw these benefits have already had a variety of heart-related health issues. Their LDL, or “bad” cholesterol and triglycerides were high even though they were taking cholesterol-lowering drugs. They also had heart disease or had diabetes and at least one other thing that made heart disease more likely.

For people who have never had a heart attack and are at normal risk of ever having a heart attack, says Manson, “It is unlikely that 4 grams per day is recommended. There is a threshold above which you can no longer see any advantages. “

A similar study found that taking a prescription form of 1.8 grams of EPA per day in addition to a cholesterol-lowering drug reduced the chances of heart attacks and other heart problems in people with high cholesterol. Many of them also had heart disease, diabetes, and / or high blood pressure. Although 1.8 grams is much less EPA than 4 grams, the study participants who were Japanese already ingested more fish oil directly from the fish in their normal diet than Westerners.

So how much is 1.8 grams of EPA exactly? Remember the grain ad that said, “You’d have to eat four bowls of raisin bran to get the vitamin nutrients in one bowl of Total?” Well, you’d need to take 10 capsules – five servings – of an average over-the-counter fish oil supplement to get 1, Get 8 grams of EPA. Do you want the full four grams? You need to take about 22 capsules. And nobody recommends that. Studies showing the benefits of high doses of EPA use prescription-only grade EPA. Over-the-counter nutritional supplements have other ingredients and are not regulated and safety-cleared like FDA-approved prescription drugs.

“Some people take several, several capsules. But we don’t know if it’s safe, ”says Manson. “If this is not under the direction of a doctor, avoid mega-doses.”

If your heart is already pretty healthy …

At lower doses, fish oil can help the hearts of people who are in good health. In a study of 25,871 adults over 50 with an average risk of heart attack, those who took 1 gram of fish oil – containing 460 mg of EPA and 380 mg of DHA (just a little more than you might find in a daily OTC dose) – took for 5 years daily a 28% lower risk of myocardial infarction during this time. But they had no less risk of stroke or death from heart disease. In fact, many studies aimed at demonstrating the lower risk of heart disease from common fish oil supplements have not done so.

If it’s not your heart you’re worried about …

Aside from heart health, researchers have studied the effects of fish oil on many other conditions. But the benefits are clear only in some of them. Fish oil could relieve rheumatoid arthritis symptoms and reduce the need for pain relievers, but only a little, research shows. And in people who have a higher than average risk of developing Alzheimer’s disease because they carry the APOE ε4 gene mutation, high doses of DHA before the symptoms appear can reduce the likelihood of the disease developing.

For other conditions, the benefits of fish oil are either absent or unclear.

Can’t I just eat fish?

Absolutely. The best way to get most of the nutrients, including omega-3 fatty acids, is through diet. In fact, several studies that do not show benefits from fish oil supplements show benefits from consuming fish. For example, while fish oil supplements don’t reduce the risk of heart disease, studies show that people who eat fish one to four times a week are less likely to die from heart disease than those who rarely or never do so. Eating fish and shellfish can reduce the risk of stroke and loss of memory and thinking skills, which can lead to dementia.

Additionally, in studies showing the benefits of fish oil supplements, those benefits may be less in people who already eat a lot of fish and more in people who are not getting enough fish.

“If there’s a rock-solid reason to supplement it’s to fill nutritional deficiencies for people who don’t consume enough fish,” said Duffy MacKay, ND, senior vice president of scientific and regulatory affairs for the Council for Responsible Nutrition, a trade association that Representing dietary supplement manufacturers and ingredient suppliers.

Take, for example, the study that showed that 1 gram of fish oil per day reduced the risk of heart attacks. That was only true for people who hadn’t yet eaten fish. The researchers divided study participants into two groups – those who ate less than one and a half servings of fish a week, and those who ate as much or more. Those who ate the least amount of fish had a 19% decrease in heart attacks, strokes, and deaths from heart disease, and a 40% decrease in heart attack risk when they took the supplement.

“They had not already consumed enough fish and were not yet at a threshold where the dietary supplements would not have any additional benefit. If they were over 1.5 servings a week, there was no clear benefit, ”says Manson.

What is the bottom line for over-the-counter fish oil?

“Fish oil is not a panacea, but the fact that the evidence is solid in some areas shows that it is an important nutrient,” says MacKay.

If you are already taking fish oil at a recommended over-the-counter dose and you are fine, there is no research that says you should stop. But don’t take any more. There is no evidence that is certain or helpful.

If you’re not ingesting fish oil, try getting it off your plate first. The American Heart Association recommends two servings – that’s about 7 ounces – of fish a week. Preferably the high-fat variety that is rich in omega-3 fatty acids.

If you are ready to start taking fish oil, talk to your doctor about side effects and interactions with medications you have already taken. The most common side effects that 1% to 10% of people experience include belching, indigestion, nausea, gas, abdominal pain, constipation, diarrhea, gas, acid reflux, and vomiting. If you are taking blood thinners, antihypertensive drugs, contraceptives, the weight loss drug orlistat (sold as Alli and Xenical), or vitamin E, talk to your doctor about interactions that could be dangerous before you start using fish oil.


JL Mehta, MD, PhD, Professor, University of Arkansas for Medical Sciences, Little Rock.

JoAnn Manson, MD, director of preventive medicine, Brigham and Women’s Hospital, Boston.

Duffy MacKay, ND, Senior Vice President, Scientific and Regulatory Affairs, Council for Responsible Nutrition.

American Heart Association: “Fish and Omega-3 Fatty Acids”.

International Journal of Molecular Sciences: “Fish, Fish Oils and Cardioprotection: Promises or Fish Tales?”

National Center for Complementary and Inclusive Health: “Omega-3 Supplements: In Detail.”

New England Journal of Medicine: “Reducing Cardiovascular Risk with Icosapent Ethyl in Hypertriglyceridemia.”

New England Journal of Medicine: “Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease.”

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