A variety of genetic and environmental factors influence peak bone mass. It has been suggested that genetic factors (those you were born with and cannot change, such as gender and race) may account for up to 75 percent of bone mass, and environmental factors (such as diet and exercise habits) account for the remaining 25 percent.
- Gender - Peak bone mass tends to be higher in men than in women. Before puberty, boys and girls acquire bone mass at similar rates. After puberty, however, men tend to acquire greater bone mass than women.
- Race - For reasons still not known, African American females tend to achieve higher peak bone mass than Caucasian females. These differences in bone density are seen even during childhood and adolescence.
- Hormonal factors - The hormone estrogen has an effect on peak bone mass. For example, women who had their first menstrual cycle at an early age and those who use oral contraceptives, which contain estrogen, often have high bone mineral density. In contrast, young women whose menstrual periods stop because of extremely low body weight or excessive exercise, for example, may lose significant amounts of bone density, which may not be recovered even after their periods return.
- Nutrition - Calcium is an essential nutrient for bone health. Calcium deficiencies in young people can account for a 5- to 10-percent difference in peak bone mass and can increase the risk for hip fracture later in life. Surveys indicate that teenage girls in the United States are less likely than teenage boys to get enough calcium. In fact, fewer than 10 percent of girls age 9 to 17 actually get the calcium they need each day.
- Physical Activity. Girls and boys and young adults who exercise regularly generally achieve greater peak bone mass than those who do not. Women and men age 30 and older can help prevent bone loss with regular exercise. The best activity for your bones is weight-bearing exercise. This is exercise that forces you to work against gravity, such as walking, hiking, jogging, climbing stairs, playing tennis, dancing, and weight training.
- Lifestyle Behaviors. Smoking has been linked to low bone density in adolescents and is associated with other unhealthy behaviors, such as alcohol use and a sedentary lifestyle. People who begin smoking at a younger age are more likely to be heavier smokers later in life. This fact worsens the negative impact of smoking on peak bone bass, and puts older smokers at additional risk for bone loss and fracture.
The impact of alcohol intake on peak bone mass is not clear. The effects of alcohol on bone have been studied more extensively in adults, and the results indicate that high consumption of alcohol has been linked to low bone density. Experts assume that high consumption of alcohol in youth has a similar adverse effect on skeletal health.