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En español | Even those who regularly pop little more than a multivitamin might be wondering if they should be taking fish oil — what with the constant news about how omega-3 fatty acids might help our health. And at least 10 percent of all Americans already take the supplement hoping to keep their hearts strong.
But can popping such a pill really protect your ticker? While a study published last year in the New England Journal of Medicine showed that taking a fish oil supplement could reduce the chance of a heart attack by up to 40 percent in those who didn't regularly eat fish, it didn't pass the test of reducing both heart attacks and strokes in a study population. In general, most in the medical community remain dubious. “The data to date, if one looks at large randomized clinical trials, which is the highest level of evidence, shows that supplements haven't been found to have any significant cardiovascular benefit,” says Deepak Bhatt, M.D., executive director of interventional cardiovascular programs at Brigham and Women's Hospital in Boston.
In 2014, JAMA Internal Medicine featured a review done on fish oil research published in major journals between 2005 and 2012. Twenty-two of the 24 studies showed no benefit. And the National Institutes of Health website has weighed in with this: “Research indicates that omega-3 supplements don't reduce heart disease.”
The news isn't much more encouraging for other health conditions. Fish oil may relieve symptoms of rheumatoid arthritis and lessen the need for pain medications, but only a little, research shows.
As for brain health, a 2012 review of data on thousands of older adults found that those who downed omega-3 fatty acid supplements had no fewer dementia diagnoses or better scores on short-term memory tests than those who popped a placebo. A report released by the AARP-founded Global Council on Brain Health (GCBH), a group including neurologists, nutritionists and researchers, which analyzed studies done on supplements claiming to boost cognition, found insufficient evidence to recommend any — fish oil included — for brain health for most adults.
Enter the Fish Oil Rx
But supplements are no longer the only way to pop fish oil, which brings us to some big news on the omega-3 fatty acid front: a prescription medication Vascepa (icosapent ethyl), which has proven to be something of a game-changer for those with certain conditions.
Made from one type of omega-3 fatty acid, called eicosapentaenoic (or EPA), extracted from sardines and anchovies and purified, the pill has been shown to help reduce the chances of heart attacks and strokes for those who have a history of cardiovascular disease or major risk factors for it, such as diabetes or high blood pressure.
According to the New England Journal of Medicine, those who took the drug in a randomized controlled study had a 25 percent reduced risk of major cardiovascular events. Vascepa is already approved and in use for those with very high levels of triglycerides. And it's expected to get expanded approval this month, allowing it to be prescribed to a larger audience. The drug is designed to be taken in addition to statin medications (which reduce LDL, or bad cholesterol).
Physicians believe the benefit may come because the medication contains only EPA at high levels — the amount of fish oil in the daily recommended dosage is 4 grams — unlike other supplements that contain both EPA and docosahexaenoic acid (DHA), another type of omega-3 fatty acid, at much lower doses. In fact, says Bhatt, who was the trial's lead investigator, “You'd have to take 20 to 25 over-the-counter supplements a day, or consume 20 to 25 servings of fish a week, to potentially get that level of EPA.” High doses of omega-3 aren't appropriate for everyone because they may pose risks, such as a slight increase in bleeding, so Bhatt suggests talking to your doctor to see if you're a good candidate for the drug.
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For Everyone Else, Just Eat Fish
Medical breakthroughs aside, doctors agree: If you're healthy and at low risk for heart disease, the best way to get any omega-3s — or any nutrient — is from the food you eat. Some studies show that consuming fish twice a week cuts your risk of heart disease or having a stroke. However, notes Erin Michos, M.D., associate director of preventive cardiology at John Hopkins School of Medicine, epidemiology is tricky. “Fish consumption has been shown with a lower association of cardiovascular risk, but it's hard to tell if it's the fish itself or the result of other healthy behaviors,” says Michos. “There are studies that show that adherence to a Mediterranean diet, which is often rich in fish, is associated with lower cardiovascular risk. But people who follow the diet may have other healthy habits. They may exercise more, schedule more prevention screenings and take good care of themselves in general, as opposed to people who eat McDonald's every day."
Another possible reason for the encouraging results: Time spent in front of a plate of salmon — or another fatty fish brimming with omega-3s — is time not spent stopping at the local fast food drive-thru for a burger and fries. As Matt Budoff, a cardiologist affiliated with UCLA Medical Center, puts it: “Fish is a smart replacement for bad things.”
The American Heart Association recommends two servings of fish a week (3.5 ounces per cooked serving), preferably the fatty kind that's rich in omega-3s. Good sources — besides salmon — include mackerel, herring, lake trout, sardines and albacore tuna. Vegetarians, people with allergies or those who dislike seafood can shop for plant-based sources of omega-3 fatty acid, including vegetables (Brussels sprouts and spinach), walnuts, flaxseed and pumpkin seeds. A caveat: Plant foods typically contain only one of the three main omega-3 fatty acids: alpha-linolenic acid (ALA), which the body turns into EPA and DHA. “The problem, though, is that only a small percentage of it is converted into EPA and DHA,” says Donald Hensrud, M.D., medical director of the Mayo Clinic Healthy Living Program and author of The Mayo Clinic Diet, so the amount of omega-3 fatty oil that people can get from those foods is pretty low. (Though, as Hensrud points out, “If someone is following a good vegetarian or vegan diet, they're probably at a lower risk for heart disease anyway.")
If you still are not ready to stop taking your fish oil supplements, know that any omega-3s are best absorbed with food that contains some (healthy) fat and that you should stick to fairly low doses. (Harvard Medical School draws the line at 1,000 milligrams a day). Also talk to your physician about potential interactions it might have with medications you take. “Fish oil has a blood thinning effect,” says Tod Cooperman, M.D., president and founder of ConsumerLab.com. “If you're on a blood thinner, or you're going to be having surgery, talk to your doctor before taking supplements.”
You should also make sure that any you already take, or shop for in the future, come with a seal of approval from places like U.S. Pharmacopeia, ConsumerLab.com or NSF International. These three independent organizations test popular supplements to see that they are properly manufactured, contain the ingredients (and doses) listed on the label, and don't contain harmful contaminants.
That's important since over-the-counter dietary supplements, unlike prescription medications, aren't closely regulated by the U.S. Food and Drug Administration to ensure that manufacturing has met high standards for quality, safety and effectiveness — so you can't always be sure of what you're swallowing, or that the doses claimed of things like fatty acids are accurate.