According to a recent study, most dietary supplements and diets have no effect on health status and death rate.
Does dieting and taking dietary supplements really do anything? Maybe not, according to one study conducted by researcher Safi Khan of West Virginia Universiy (USA) and published in the journal Annals of Internal Medicine. The latter analyzed the results of 277 randomized studies, bringing together more than a million participants, to understand how dietary supplements and diets influence mortality rates and cardiovascular health.
Folic acid and omega 3
“We initiated this study because millions of people in the United States and around the world take dietary supplements or follow certain diet patterns, but there was no evidence that these behaviors had any effect on protection against heart disease,” says Safi Khan. Of the 16 dietary supplements studied, only two seem to be beneficial: folic acid and omega 3, two long-chain fatty acids. The first would protect against cerebrovascular accidents (CVA) and the second would reduce the risk of heart attacks and coronary diseases.
The study also looked at the impact of these supplements and diets on all-cause death rate, cardiovascular death rate, risk of heart attack, stroke, and coronary heart disease.
Result: consuming calcium and vitamin D at the same time can be dangerous and increase the risk of stroke. However, taking calcium or vitamin D separately would have no effect on health. This is also the case for all the other supplements analyzed by the study, such as multivitamin supplements, iron, folic acid, beta-carotene and antioxidants.
More or less solid results
Regarding diets, eating less salt, for example, increases the risk of death from all causes in people without high blood pressure, but lowers the risk of death from heart disease in people with high blood pressure. The low sodium diet is the only one that would have a significant effect.
The other seven diets studied, such as eating less or adopting a diet focusing on different types of fat, had no effect on health. Regarding that of a diet with less sodium, it is supported by logic and by sufficient data from other studies. But the evidence on which the results for folic acid and omega 3 are based is less robust.
“Randomized studies lack precision, explains Khan. They are problematic in terms of methodology, target populations and construction. The results must therefore be taken with a grain of salt.”
.
