The effect of whole blueberry consumption on body composition, physical activity, and serum oxidative and inflammatory biomarkers in postmenopausal osteopenic women
Postmenopausal women are at an increased risk for chronic diseases, including cardiovascular disease, cancer, diabetes, and osteoporosis. Metabolic changes that occur after menopause contribute to an increase in fat mass, increased abdominal obesity, and increased serum inflammatory and oxidative biomarkers. Blueberries are rich in polyphenols and may aid in disease prevention after menopause. The purpose of this study was to examine the effect of daily blueberry consumption on body composition, physical activity, inflammation, and oxidative stress in postmenopausal women with osteopenia. A total of 40 women were recruited and randomized into two groups for 12 weeks, or 90 days. Group 1 (n=20) served as the intervention group and consumed 40 grams of lypholyzed blueberry powder each day. Group 2 (n=20) served as the control group and received a placebo mixture consisting of an equal ratio of fructose and dextrose equivalent to the lypholyzed blueberry powder in appearance and calorie content. DEXA scans were performed at baseline and final assessments to evaluate body composition and body weight. Serum specimens and self-reported physical activity questionnaires were collected at baseline, midpoint, and final assessments. At the end of the 90-day study, both the blueberry and placebo group experienced a decline in body weight and BMI, with the decrease in the intervention group being significant in comparison to baseline. There was a slight reduction in abdominal fat mass in the blueberry group, whereas the placebo group had a slight increase, although neither group had significant changes. Both groups experienced a decline in whole body fat, with a greater decrease in the blueberry group. However, this change did not reach a level of significance. There were no significant changes seen in plasma levels of TBARS, CRP, or IL-6 in the intervention group. The placebo group, however, had a significant increase in IL-6 concentrations between the midpoint and final assessments. There were no significant differences found between baseline, midpoint, and final of physical activity and sleep patterns in either the placebo or blueberry group. This study indicates that regular blueberry consumption may have a positive effect on body weight, and therefore, positively influence disease risk and prevent inflammation over time.