A new study says that few nutritional supplements can protect people from developing or dying from heart disease.
The researchers wanted to find out if 16 different nutritional supplements and eight special diets had an effect on the risk of heart problems and strokes.
For the answer, the researchers examined the results of 277 studies, which involved nearly one million people. Their results were reported in the medical publication Annals of internal medicine.
The Department of Agriculture of the United States has identified two diets, what it calls eating models, as examples of healthy ways of eating. Dietary guidelines for Americans 2015-2020 identify one as the Mediterranean-style diet. It is rich in fruit, vegetables, legumes, whole grains, fish and healthy fats. Studies have linked this type of diet to improve heart and brain health.
A vegetarian diet, one that does not include meat, has been linked to a lower risk of heart disease.
The researchers say there is little evidence to support the use of food supplements. Yet about half of US adults take at least one supplement to improve their health.
Some dietary measures have helped
The researchers found evidence that the reduced use of salt was linked to a lower risk of death from all causes among people with normal blood pressure.
Some supplements seemed to have a good effect on human health. Omega-3 fatty acids seemed to reduce the risk of heart attack and heart disease in adults.
In addition, folic acid, a vitamin B, seemed to lower the risk of stroke: blockages in blood flow that can damage the brain or cause death.
However, the study suggested that the combination of calcium and vitamin D could increase the risk of stroke.
For other common supplements, there does not appear to be any major effect on the risk of death or cardiovascular health, the researchers said. These supplements include only selenium, vitamin A, B6, C, E and vitamin D.
Calcium alone, folic acid and iron do not seem to help heart health. Not even food models like the Mediterranean diet. Research has suggested that reduced saturated fatsthe reduced fat content in the diet or the use of fish oil supplements did not help the heart.
The large studio had a lot of information on many people. He used a method of random have patients take supplements while others do not. This method is generally considered effective. But the researchers admit that there were limits to their study.
One was so different doses or the amounts of supplements have not been compared over different time periods.
However, the researchers said there is enough evidence to suggest that people should not start taking supplements if they want to prevent heart problems.
Eric Topol is an official with Scripps Research in La Jolla, California. He told Reuters news agency that he was in agreement with the results.
"There are not convincing data that any vitamin or supplement reduces heart attacks, "he said.
Topol was not involved in the study.
The guide author of the report was Safi Khan of the University School of Medicine in Morgantown, West Virginia. He wrote that people should receive their food from a large group of foods.
"People should focus on the healthy diet from nutritional food sources, not on vitamins or supplements, combined with a healthy lifestyle that includes regular exercise and not smoking, "he wrote.
I'm Mario Ritter Jr.
Lisa Rapaport reported this story for the Reuters news agency. Mario Ritter Jr. adapted the report for VOA Learning English. George Grow was the publisher.
Words in this story
supplement -n. something added (to a person's diet) that makes it more complete or healthier
template -n. the use of certain things (such as food) that are performed on a regular or repeated basis
legume -n. plants tied to peas and beans that grow seeds in pods
cardiovascular -ADJ. tied to the heart or blood vessels that carry blood throughout the body
saturated fats -n. a form of fat commonly found in animal products and in some plant products such as coconut
random -adv. done in a way that is not planned or decided
to convince -v. to persuade
author – n. the writer of a paper or a book; the creator of something
focus -v. to direct attention to something specific
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