Effect of a Calcium-Enriched Lemon Beverage on Bone Metabolism and Bone Mineral Density in Postmenopausal Women: A Double-Blind, 11-Month, Intervention Study

Background Key approaches to preventing the onset of osteoporosis are to maximize peak bone mass (PBM) in early adulthood and to minimize the inevitable loss of bone mineral density (BMD) after menopause. Consequently, osteoporosis attracts a great deal of social as well as medical attention in Japan, a country experiencing population aging. Methods The present randomized, controlled study aimed to elucidate how bone metabolism and bone mineral density (BMD) are affected by the consumption of a lemon juice-containing, calcium-enriched beverage. The effectiveness of this investigational product was evaluated in 79 postmenopausal women. The subjects were assigned to three groups. The first two groups received calcium-supplemented (LECA group) and unsupplemented lemon (LE group) beverages, respectively. The third group (control) received no intervention. The LECA and LE groups consumed one bottle (290 ml) of the appropriate investigational product every day for 11 consecutive months. Results The results showed that the regular consumption of this lemon beverage promoted Ca absorption through the chelating function of citric acid, attenuating bone resorption. The results also suggest that the suppression of bone resorption inhibits bone formation mediated by the differentiation and activity of osteoblasts and leads to the prevention of high-turnover bone metabolism. Conclusion This hypothesis is further supported by the novel finding that the regular consumption of the lemon beverage increases the BMD of both the lumbar spine and femur. We believe that the Ca-supplemented lemon beverage used in the present study will be instrumental in developing effective strategies for the prevention of osteoporosis.