Most Nutritional Supplements Don’t Actually Help You Live Any Longer – runnersworld.com

• A new analysis published in the Annals of Internal Medicine of 277 clinical trials that involved 24 supplements found that most do not do anything to protect against heart attack or stroke, or help you live longer.
• There was some evidence in favor of omega-3 fatty acids, a low-salt diet, and folate.
• A combination of vitamin D and calcium may be risky, the study found.

Numerous supplements like multivitamins, calcium, vitamin E, and omega-3 fatty acids are popped daily for heart health by millions of Americans—many of whom also try to eat right by following plans like the Mediterranean diet.

The problem, a recent study suggests, is there isn’t much evidence any of that helps your ticker in the long run, at least not enough to keep it pumping for longer than it would have without those strategies.

New research published in the Annals of Internal Medicine reviewed data from 277 clinical trials that involved 24 supplements—vitamins, minerals, omega-3s, and antioxidants—and eight diets, including the Mediterranean, reduced salt, and low-fat. In all, nearly a million participants were included.

The research focused on randomized controlled trials—which means participants are assigned to specific interventions for a certain period of time—instead of observational studies, or hose that might ask participants to estimate multivitamin use over a few decades, for example.

That methodology is significant, lead study author Safi Khan, M.D., of West Virginia University, told Runner’s World. Nutrition studies taken solely from participant recall are often criticized for a lack of rigor, but these type of trials are considered the “gold standard” of research, even though many also use food logs. That’s because they test certain variables directly, rather than relying on associations between different factors.

Researchers found a few tactics that provided a modest benefit: reduced salt intake, omega-3 supplements, and taking folate proved to reduce some risk for heart attacks and stroke, but not enough to send everyone zooming toward the supplements aisle.

For instance, interventions testing omega-3s found that the supplement reduced the risk of heart attack by eight percent, and the chances of heart disease by seven percent. Trials on folic acid found a 20 percent lower risk of stroke, and a low-salt intake was linked to a 10 percent reduction in early death—but that was the only supplement or way of eating found to have an association with checking out early.

The rest of the supplements didn’t even show that slight bump in effect. Vitamins like A and B6, along with multivitamins, antioxidants, and iron had zero effect on early mortality or cardiovascular disease prevention. Dietary interventions like reduced fat had the same result, as did the Mediterranean diet, surprisingly.

One combination, calcium taken with vitamin D, even proved potentially harmful, since it can increase blood clotting and risk of hardened arteries—two outcomes that raise stroke risk, Khan said. In fact, the analysis concluded that the combination was linked to a 17 percent increase in stroke.

Plus, there’s even a caveat about folate, since that data comes from a study done in China, where folic acid deficiencies are common.

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That actually fits in with Khan’s advice about supplements, which is that they may have some benefit if you’re actually deficient in the nutrient. But taking them as a kind of heart-health insurance policy isn’t one that pays off.

“It’s possible that you could see some effect if you take these supplements as a way to improve your health,” he said. “But what we’re trying to show here is that the evidence for that is very weak.”

Khan and his fellow researchers aren’t the first to suggest supplements might be expensive placebos. A report in 2013 from the U.S. Preventive Services Task Force found “limited evidence” supporting claims that vitamin and mineral supplementation could help prevent cancer or cardiovascular disease.

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But what about that much-loved Mediterranean diet? In that case, some of the trials found modest improvements in cardiovascular risk, but Khan said the evidence is simply not convincing enough to issue a blanket recommendation that this is how everyone should be eating.

“The fact is that there’s no single magic diet that’s good for everyone, the evidence doesn’t support that,” he said. “Maybe after many more trials we’ll see that, but for now, what’s helpful is to focus on what we know is good, like eating more vegetables, and combining that with exercise and not smoking.”