Osteoporosis and Lifestyle.

Skeletal tissue is formed during the first two decades of life; then a constant bone mass is maintained until 40 y of age. In the case of women, the bone mass is rapidly reduced at menopause at around 50 y of age. After that, bone mass slowly decreases in both men and women who have passed the 70-y-old mark. The National Institute of Health Consensus Conference adopted the definition of osteoporosis as a skeletal disorder that is characterized by compromised bone strength leading to a predisposition for and an increased risk of fracture. Since osteoporotic fractures are the third-highest cause for becoming bedridden, the maintenance of healthy bones is an important factor in extending a person's healthy lifespan. Bone mass is influenced by many factors, such as nutrition, physical activity, smoking and alcohol intake, as well as by genetic factors. Thus, a healthy diet providing balanced nutrients including calcium, vitamin D, vitamin K and protein, regular physical activity, and not smoking help maintain bone health and delay or prevent osteoporosis. Some functional foods containing soy isoflavones, milk basic protein and n-3 fatty acid may help promote bone health.