As background information, the authors explain that although dietary changes, physical activity and some prescription medications have been scientifically demonstrated to reduce cardiovascular disease risk, a considerable number of people seek out alternative therapies, such as dietary supplements.
There is compelling evidence that some supplements, such as fish oil, do help in the treatment and prevention of cardiovascular disease. However, there are several supplements which are marketed to consumers for which safety and efficacy evidence is lacking.
Rebecca L. Drieling, M.P.H., M.M.Q., of Stanford University School of Medicine, Stanford, Calif., and team carried out a placebo controlled, double-blind, randomized trial on pine bark extract supplements. It included 130 participants who were deemed to be at higher risk of cardiovascular disease. They were selected at random to either receive 200 milligrams of pine bark each day for 12 weeks, or a placebo. They were asked not to start taking any different medications or new supplements, not lose weight or change their diet during the study. Cardiovascular risk factors, such as blood pressure readings were taking at the beginning of the study, and then again at 6 and at 12 weeks.
The investigators found absolutely no difference in baseline risk factor for heart disease between the pine bark and placebo groups.
The researchers found that:
- Blood pressure dropped 1.9 millimeters of mercury among the placebo group participants
- Blood pressure dropped 1 millimeter of mercury among the pine bark group participants
- There were no significant differences in levels of insulin, lipoproteins, fasting blood glucose, body mass index, blood cholesterol, liver enzymes, and inflammatory marker C-reactive protein between the two groups.
After assessing blood pressure levels among individuals with particularly higher cardiovascular disease risk, the scientists still found no differences between those on the pine bark and those on the placebo.