CHICAGO (Reuters) - Popular supplements made from pine bark extract do nothing to reduce blood pressure or lessen other heart risk factors in high-risk patients, U.S. researches said on Monday.
The study is the largest, most scientifically rigorous yet to look at the effects of pine bark extract, a powerful antioxidant. The leading brand is Pycnogenol sold by Natural Health Science, but it is sold by different names by other companies.
Smaller, less rigorous studies have suggested the extract, made from the French maritime pine, Pinus pinaster, helped lower blood pressure. A team at Stanford University in California put this claim to the test.
They studied a Japanese product called Toyo-FVG made by Toyo Shinyaku Co in 130 overweight people who had high blood pressure but were not taking drugs for it.
"The antioxidant mechanism is thought to interfere with several the biological mechanisms that cause blood pressure to increase," Dr. Randall Stafford, who worked on the study published in Archives of Internal Medicine, said in an e-mail.
Half of the volunteers got a dummy pill and half took a 200 milligram daily dose of pine bark extract.
"We found no difference in the change in blood pressure between the pine bark extract group and the placebo group," Stafford said in an e-mail.
"In fact, there was a slightly greater reduction in blood pressure among the placebo group that could have easily been explained by random chance," he said.
There was no difference between the groups in any of the other risk factors, such as cholesterol, body weight or blood sugar.
The team concluded that despite claims that the extract promotes heart health and healthy circulation, there were no apparent heart benefits from taking it.
"While we found pine bark extract to be a very safe supplement with no benefits, this is not necessarily true of other supplements," Stafford said.
Unlike prescription drugs, the U.S. Food and Drug Administration does not approve dietary supplements before they can be sold. The Federal Trade Commission regulates the marketing of herbal supplements, which are not allowed to claim that they treat medical conditions.
But calls for stronger oversight have been growing.
Stafford said people are spending billions of dollars on products without knowing whether they are safe or effective.
"It is time for the FDA to start treating supplements more like drugs and provide consumers with more active guidance about how to critically evaluate their decisions to purchase supplements," he said.
Toyo Shinyaku supplied both the supplements and the placebo pills. None of the researchers has financial ties with the company.