Pine Bark Extract Safe, But May Not Reduce Heart Disease Risk Factors
In new research from Stanford University, pine bark extract appears to be a safe dietary supplement, but likely will not help lower blood pressure or reduce other heart disease risk factors such as cholesterol, blood sugar or body weight.
Dr. Randall Stafford, an associate professor of medicine at Stanford Prevention Research Center, and colleagues recruited 130 overweight subjects that had high blood pressure but were not taking medication. The participants were given either a 200 milligram per day dose of pine-bark extract or a placebo, but were asked not to change their diet in any other way. At the beginning of the study (baseline), at midpoint (6 weeks) and at the end of 12 weeks, blood pressure, and other factors such as blood cholesterol, liver enzymes, insulin and fasting glucose were tested.
In both groups, both systolic and diastolic blood pressure decreased slightly – 1.0 mmHg in the treatment group and 1.9 mmHg in the control (placebo) group. Interestingly, those taking pine-bark extract had a slight increase in body mass index while the placebo group experienced a slight drop.
"We found no difference in the change in blood pressure between the pine bark extract group and the placebo group," said Dr. Stafford. "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.
Pine bark is extracted from the tree Pinus pinaster and contains antioxidants such as oligomeric proanthocyanidin that are thought to interfere with several biological mechanisms that cause blood pressure to increase. The supplement is also thought to reduce levels of inflammation in the body by counteracting free radical damage.
The supplement appears to be safe, with the most common side effects being headache, sleepiness, frequent urination, gastrointestinal tract discomfort, and insomnia.
"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," said Stafford. "There's also a broader message that many dietary supplements don't have the data to back up their claims of providing health benefits."
Drieling R, et al "No beneficial effects of pine bark extract on cardiovascular disease risk factors" Arch Intern Med 2010; 170: 1541-1547.