Vitamins and other supplements are getting a bad rap lately. The AARP reported last month that they have no demonstrable effect on brain health. And now researchers say there is little evidence that supplements or certain diet modifications protect heart health or improve cardiovascular outcomes.

Available research is of “suboptimal quality and certainty of evidence,” wrote Safi Khan, M.D., after he and colleagues conducted a large data analysis. There is moderate evidence that reducing salt intake lowers mortality risk in certain patients, and lower-certainty evidence that omega-3 LC-PUFA use and folate supplementation have benefits. Calcium plus vitamin D “might” increase stroke risk, the researchers found. Aside from that, the data is unclear.

“Unfortunately, the current study leaves us with the same foggy conditions that we started with,” wrote the authors of an accompanying editorial. “Until these conditions clear, it would be reasonable to hold off on any supplement or diet modification in all guidelines and recommendations.”

The researchers reviewed findings from 277 trials and 24 interventions, involving nearly one million participants. One author disclosed financial ties to the pharmaceutical industry.

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