No effect of pine bark extract on cardiovascular disease risk
Pine bark extract is a dietary antioxidant supplement.
In this study, researchers at Stanford University School of Medicine, in California, attempt to correct past studies that they consider flawed.
First, the details.
- 130 people with increased cardiovascular disease risk were randomly assigned to a treatment group.
- 200 mg of a water-based extract of pine bark (marketed as Flavagenol in Japan) once per day
- Placebo
- Blood pressure and other cardiovascular disease risk factors were measured at the start of the study and at 6 and 12 weeks.
And, the results.
- Over 12 weeks of treatment the sum of systolic and diastolic blood pressures decreased 1 mmHg with pine bark extract and 2 mmHg with placebo — not a significant difference.
- There was also no difference in body mass index, cholesterol and liver enzyme levels, and levels of insulin, lipoprotein(a), fasting blood sugar, and high-sensitivity C-reactive protein (reflects ongoing inflammation).
- There were no subgroups of people for whom pine bark extract altered cardiovascular disease risk factors.
The bottom line?
The authors concluded, “This pine bark extract (at a dosage of 200 mg/day) was safe but was not associated with improvement in cardiovascular disease risk factors.”
Looking at the big picture, the authors state further, “Our results are consistent with a general failure of antioxidants to demonstrate cardiovascular benefits.”
Over the past decade, a series of positive studies of pine bark extract have been published. Many can be reviewed here, and another reporting a positive effect on cardiovascular risk factors is here.
The Stanford researchers tell us that past studies were poorly designed. However, many of these studies also used Pycnogenol, a specific brand of pine bark extract that’s produce using a different extraction process.
It’s unclear what effect this might have had on study outcomes.
9/28/10 20:39 JR