With Sally Wadyka
Dietary supplements are intended to provide nutrients that may otherwise not be consumed in sufficient quantities. Supplements as generally understood include vitamins, minerals, fiber, fatty acids, or amino acids, among other substances.
The majority of adults in the United States take one or more dietary supplements either every day or occasionally. Today’s dietary supplements include vitamins, minerals, herbals and botanicals, amino acids, enzymes, and many other products. Dietary supplements come in a variety of forms: traditional tablets, capsules, and powders, as well as drinks and energy bars. Popular supplements include vitamins D and E; minerals like calcium and iron; herbs such as echinacea and garlic; and specialty products like glucosamine, probiotics, and fish oils.
Walk into any pharmacy or health-food store and you’ll see shelves of dietary supplements that promise to help your heart, such as omega-3, coenzyme Q10 (CoQ10), and red yeast rice.
Proponents claim that these products can lower blood pressure or cholesterol, stave off heart disease, and prevent heart attacks. If you’re concerned about your heart health, should you be taking them?
What the Science Says About Supplements
Omega-3 (fish oil). It’s well-established that regularly consuming foods that contain omega-3 fatty acids (see “Ticker-Friendly Foods,” below) is a bonus for heart health. Fish, and especially fish oil, have also been the subject of dozens of randomized clinical trials, most involving people with existing heart conditions. In large amounts (several grams a day), fish oil has been shown to nudge various cardiac risk factors (“good” HDL cholesterol, triglycerides, blood pressure) in the right direction. Smaller amounts (a gram a day) work against irregular heart rhythms — particularly atrial fibrillation, the chaotic beating of the heart’s two upper chambers. Fish oil is believed to block the sodium channels in the membranes of heart muscle cells, making them less likely to “misfire” and contribute to irregular beating. But the evidence on supplements has been scant.
However, a recent scientific advisory report from the American Heart Association, published in the journal Circulation, concluded that people who have already had a heart attack or been diagnosed with heart failure may benefit from a daily 1,000-mg fish-oil supplement. For that group only, according to the AHA, this practice could reduce the risk of dying from heart disease by 10 percent.
“The benefits shown in recent studies have been modest, but I think taking them is still reasonable,” says JoAnn Manson, M.D., chief of the division of preventive medicine at Brigham and Women’s Hospital in Boston.
Cause for Caution
With over-the-counter dietary supplements, you don’t always know what you’re getting.
“There’s a lack of regulation, which means the content, identity, and purity of the product is not guaranteed,” says Consumer Reports’ chief medical adviser, Marvin M. Lipman, M.D.
Manson agrees. “There are some high-quality supplements, but it’s very much buyer beware,” she says.
There’s also a risk that some supplementsmay include unwanted ingredients, interact with medications you take, or cause side effects.
For example, red yeast rice supplementscan contain a chemical that’s been linked to kidney damage. It can also magnify the effects of statin drugs. CoQ10 may reduce the effectiveness of blood thinners, which are often used to help prevent heart attacks and strokes. Fish-oil supplements can lead to bleeding problems when combined with prescription blood thinners.
Be sure to discuss any supplements you’re taking or considering with your physician. “You can run into serious problems with drug interactions if your doctor doesn’t know,” Manson warns.
Fish-oil supplements have shown mixed results in research, and most experts agree that the best way to get the heart benefits of omega-3 fatty acids is through food.
“There’s no doubt that diet plays a big role in heart disease,” Lipman says. “And if you have a good diet, you don’t need supplements.”
Getting fish oil into your diet can be difficult. Eating fish will certainly do it — if you feast on salmon, trout, mackerel, and other oily species. A three-ounce serving of those fish supplies about a gram’s worth. But you’d need to eat more than a pound of farmed catfish to get that much fish oil. Or 12 ounces of light tuna canned in water.
So fill your plate wisely with plenty of foods rich in omega-3s, such as fatty fish like salmon, mackerel, and sardines; flaxseed; chia seeds; and spinach.
Admin’s Note: Part of this article also appeared in the Consumer Reports on Health newsletter.