Aging and Chronic Disease
Objectives : After the onset of menopause, the risk of cardiovascular disease increases drastically due to ovarian hormone deficiency. Grapes are high in polyphenolic compounds that have antioxidant and anti-inflammatory properties. The present study examined the effects of freeze-dried whole grape powder (GP) in reducing cardiovascular disease risk factors.
Methods : In this double-blind, placebo-controlled trial, 40 postmenopausal women (1 to 5 years past menopause), not on hormone therapy, were randomly assigned to consume either 46 g of GP or grape placebo powder for 12 weeks. Fasting blood samples, anthropometrics, blood pressure, physical activity, and dietary data were collected at baseline and after 12 weeks of the intervention. A mixed-effects model (PROC MIXED) was used to examine the effects of time, group, and the interaction between time and group. Paired t-tests were performed to compare changes from baseline within the group. P < 0.05 was considered statistically significant.
Results : Thirty-two women successfully completed the study. There was a significant time x group interaction effect observed for serum triglyceride (TG) (p < 0.05) and a borderline significant time x group interaction effect observed for serum total cholesterol (TC) (p = 0.06). In addition, a significant main effect of group was found in fasting glucose (p < 0.05), but without significant impacts of time and time x group interaction. Within-group analysis showed that the serum levels of TG significantly decreased by 26% (p < 0.05), while the serum levels of TC and low-density lipoprotein cholesterol numerically decreased by 8% and 11%, respectively after 12 weeks of GP consumption compared with corresponding baseline values. Neither GP nor placebo powder significantly altered body weight, high-density lipoprotein cholesterol, blood pressure, insulin or homeostatic model assessment-insulin resistance.
Conclusions : Our findings show that daily consumption of grapes lowers serum levels of TG in postmenopausal women. Larger follow-up studies are needed to ensure the validity of these findings.
Funding Sources : This research was funded by the California Table Grape Commission. Funders had no role in the study design, data collection, data analysis or interpretation, or writing of the abstract.