Osteoporosis is a deterioration of bone tissue resulting in porous, fragile bones which are vulnerable to fractures. It affects both women and men, though women are more at risk, and it typically occurs later in life, affecting people 50 and over more than younger people.
Calcium and Osteoporosis
Because bones are made from calcium, and bone tissue is being constantly remodeled by the body, ensuring an adequate intake of dietary calcium is important for long term bone health. It is important to remember that osteoporosis can be caused partly by a lifelong deficiency of calcium; prevention must take the form of a regular balanced diet consumed habitually over the course of an entire lifetime.
Calcium is readily available in dairy products of all kinds, such as milk, yogurt, cheese, and even ice cream, though many of these products are also high in fat. Many people take a vitamin supplement in order to increase their calcium intake: a combined calcium and vitamin D supplement is particularly effective for bone health. Some prepared foods such as cereal and orange juice are also fortified with calcium. But there are many sources of dietary calcium which are overlooked, and which contribute to overall health; dark green vegetables such as broccoli and spinach are excellent sources of dietary calcium, as are tofu, almonds, and some fish (such as sardines or salmon).
Exercise and Bone Density
Bone is not a static framework, but is actually made up of living tissue which is constantly being remodeled. Two kinds of specialized cells keep bones healthy. Osteoclaths break down old bone tissue and osteoblaths build new bones using calcium as a building material. When these two activities do not balance out, obviously, bone loss will result.
Exercise, especially exercise which places stress or weight on a bone, increases the activity of osteoblaths in that bone. This means that weight bearing exercise plays an important role in preventing osteoporosis and maintaining healthy bones. Calcium is just the raw material for bones: active osteoblaths are needed to turn that calcium into new bone. This mechanism may partly explain why rates of osteoporosis are high in the U.S. even though Americans also consume a lot of dairy products.
Alcohol and Bone Health
Drinking alcohol, at least more than moderate amounts of alcohol, may also have a negative effect on long-term bone health. Alcohol can upset the body's relationship to calcium, both by interfering with the hormone that regulates calcium levels, and by lowering the amount of calcium the body can absorb from food. Alcohol may also reduce the activities of bone-building osteoblaths and even stimulate the osteoclaths that break down old bone. Like a lack of exercise, then, heavy alcohol use can contribute to bone loss. Finally, people who drink more than two or three alcoholic beverages a day may have poorer diets than those who drink moderately or do not drink at all, meaning less calcium intake.
Smoking is also correlated with osteoporosis, though whether this is because smoking directly affects bone health, or because of shared or indirect effects is unknown.
