First North American Study Supports Whole Grape Extract for Lower Cholesterol

February 13, 2014

The study is the first North American, double-blind, placebo-controlled trial to examine grape extract for cholesterol health.

A patented, whole grape extract may help lower cholesterol, according to a new, six-week pilot study published in the Journal of Functional Foods. The study is the first North American, double-blind, placebo-controlled trial to examine grape extract for cholesterol health.

The study looked at the effects of a whole grape extract (WGE)-Ethical Naturals’ (San Anselmo, CA) VinCare ingredient-on the antioxidant status and lipid profile of 24 pre-hypertensive, overweight, and/or pre-diabetic subjects aged 18-65. Subjects were given either placebo or a 350-mg daily dose of VinCare. VinCare comprises 60%-70% proanthocyanidins, including flavan-3-ols catechin, epicatechin, and epicatechin-3-O-gallate. Participants were asked to avoid foods and beverages rich in antioxidants and polyphenols during the trial.

The researchers took fasting blood samples at screening and at week 6, as well as urine samples at baseline and at week 6, in addition to measuring blood pressure, heart rate, and weight. Blood samples were analyzed for total antioxidant capacity, oxidized LDL (bad) cholesterol, and HDL (good) cholesterol, among other factors. Urine samples were analyzed for multiple factors, including 8-isoprostane, which is a biomarker for oxidative stress and lipid peroxidation-all detrimental to heart health.

The VinCare group saw a 0.5% decrease in oxidized LDL, while the placebo group saw a 5% increase in oxidized LDL. The oxidized LDL changes did not reach statistical significance between the two groups, however. The researchers noted that this may be due to the study’s short duration. “It is possible that either greater dosage or longer supplementation duration was required in order to detect changes in oxLDL,” they wrote.

Additionally, there was a statistically significant HDL cholesterol difference between the VinCare and placebo groups. VinCare subjects had increased HDL cholesterol, while HDL levels dropped in the placebo group.

Moreover, the VinCare group experienced a 5% decrease in 8-isoprostane concentration, compared to a 50% increase in the placebo group-a difference that researchers said “approached significance.”

Interestingly, though, the VinCare group scored significantly lower in the antioxidant superoxide dismutase, which researchers said may be due to the age of the VinCare subjects. “In this study, the younger ages of participants on placebo compared to those on WGE may explain the observation that though both groups had increases in plasma total antioxidant capacity from baseline to week 6, only the increase for participants on placebo was significant.”

Overall, the results link VinCare with heart health benefits, despite the study’s small sample size, “high individual variation,” and short duration, the researchers said.

They also pointed out that this is the first North American study of its kind on whole grape extract. While there have been some studies on the effects of grape skins, raisins, and resveratrol-enriched grape extract, “as far as we are aware, this is the first randomized controlled clinical trial for a whole grape extract conducted in North America.”

The study was performed by KGK Synergize (London, ON, Canada) and funded by Ethical Naturals.