Pine-bark extract has no effect in lowering blood pressure or reducing heart disease risk factors, researchers have concluded.
The extract was reputed to have beneficial properties because it is an antioxidant, which means that it counteracts the effects of free radicals, the oxygen molecules that can damage cells in the body.
But a study at Stanford University, California, USA, published in the Archives of Internal Medicine, has found that it proved to have no benefit at all.
Senior author Dr Randall Stafford, associate professor of medicine at the Stanford Prevention Research Center, said the findings are part of a growing body of evidence that antioxidant supplements don’t improve heart function.
"While there’s a good biological basis to presume that antioxidant supplements might have a beneficial effect on heart health, this study is another example that they don’t," he said. "There’s also a broader message that many dietary supplements don’t have the data to back up their claims of providing health benefits."
In the largest randomised, placebo-controlled clinical trial to date, Stanford researchers recruited 130 overweight individuals who had blood pressure above an optimal level but were not taking medication for it.
They were randomly assigned either a 200mg Japanese-produced pine-bark extract a day or a placebo. Blood-pressure readings and blood samples were taken before the study began, at six weeks and then again at the end of the 12-week study period.
The researchers found that their blood pressure levels, as well as other risk factors for heart disease, including cholesterol, blood glucose, body weight and C-reactive protein levels, remained virtually the same in both groups throughout the study.
"We conducted additional analyses to see if there were subgroups of patients who might have received a benefit from the supplement, but none of them did," Stafford said.
The study concludes: “Although a different dosage or formulation might produce different results, our findings argue against recommending this pine bark extract to improve cardiovascular disease risk factors.”
* Arch Intern Med. 2010;170[17]:1541-1547
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