Will Tomatoes Prevent Osteoporosis?

Osteoporosis is a major metabolic bone disease that occurs primarily in women over the age of 50 because of the loss of estrogen during menopause. Oxidative stress as a risk factor for osteoporosis has garnered a lot of interest. Caused by reactive oxygen species (ROS), oxidative stress is involved in the activity and function of osteoblasts and osteoclasts, the two major bone cells implicated in the pathogenesis of osteoporosis. However, the cellular and molecular mechanisms involved in this association, the action of ROS, and the role played by dietary antioxidants (eg, lycopene) are not clear and the subject of continued study. Lycopene is a potent antioxidant that is present mainly in tomatoes and tomato prod- ucts, as well as in small amounts in some fruits and vegetables. Based on epidemiological data, clinical studies, and in vitro cell culture studies, lycopene has been associated with the prevention of major human chronic diseases, including certain types of cancer, cardio- vascular disease, hypertension, macular degenerative disease, and male infertility. The ongoing clinical study at the Calcium Research Laboratory at St. Michael's Hospital is the first to evaluate lycopene in nutritional supplement and tomato juice in the prevention of osteoporosis in postmenopausal women. This issue of Endocrinology Rounds focuses on this ongoing research and the role of oxidative stress as a risk factor for osteoporosis.