Nutrition Science and Everyday Application - beta v 0.1

INTRODUCTION TO BONE HEALTH 501
Figure 9.3. Age and bone mass. Bone density peaks at about 30 years of age, and women lose
bone mass more rapidly than men, particularly around menopause.
Risk factors that can be controlled:
• Physical inactivity- Physical inactivity lowers peak bone mass, decreases BMD at
all ages, and is linked to an increase in fracture risk, especially in the elderly.
Regular exercise can help individuals achieve greater peak bone mass, prevents
bone loss for women and men age 30 and older, and maintains strength and
balance to help prevent falls later in life. The best activities for stimulating new
bone are weight-bearing exercise, such as walking, hiking, and dancing, and
resistance exercises like weight lifting.
• Nutrition- Ensuring adequate nutrition is a key component in maintaining bone
health. Having low dietary intakes of calcium and vitamin D are strong risk factors
for developing osteoporosis. Protein is also important during childhood and
adolescence for proper bone development, and in older age to preserve bone
mass. 4
• Smoking- Smoking cigarettes has long been known to correlate to a decrease in
bone mass and an increased risk of osteoporosis and fractures. However, because
people who smoke are more likely to be physically inactive and have poor diets, it
is difficult to determine whether smoking itself causes osteoporosis. Smoking is
also linked to earlier menopause, and therefore the increased risk of developing
osteoporosis among female smokers may also be attributed, at least in part, to
having reduced estrogen production at an earlier age. However, studies have also
shown that tobacco smoke and nicotine can directly impact bone metabolism. 5