Moderate consumption of blueberries may effectively reduce bone loss in healthy postmenopausal women.
The research began with a blueberry dose-response study with ovariectomized rats, used as an experimental model simulating postmenopausal conditions. These rats were fed with various doses of blueberry powder, with the aim to identify an optimal dosage for bone calcium retention. The experiment then translated to a human study where fourteen healthy women, all more than four years past menopause, were examined. A baseline was established, and then each participant was provided with varying dosages of freeze-dried blueberry powder equivalent to defined portions of fresh blueberries, to be consumed daily for a series of six weeks at a time. Tracing calcium in the urine was employed as a method to monitor bone calcium balances in both the rat and human trials.
The collected data indicated that both the rat and human subjects benefited from blueberry interventions at lower doses. Higher doses, however, showed no such beneficial impact on bone calcium balance. In human subjects, net bone calcium retention increased with low and medium doses of blueberry consumption. Increased urinary excretion of hippuric acid, a metabolite of the antioxidants present in blueberries, was observed with an increase in blueberry consumption. No significant associations were found between bone resorption biomarkers and the interventions implemented in the study.
