Effecten van calcium en alcohol op botten.* 

Oudere vrouwen die een calciumrijkdieet volgen en af en toe een glaasje drinken hebben minder botontkalking dan zij die dat glaasje weglaten. Niet roken en het vermijden van cafeïne is ook goed voor de botten.

- Elderly women who consume a calcium-rich diet and occasionally drink small amounts of alcohol may be less likely to have bone thinning than their peers, researchers report. Avoiding cigarettes and caffeine can also be beneficial for older women's bones, according to researchers at the University of Connecticut School of Allied Health. Some studies have suggested that moderate alcohol consumption can have a beneficial effect on bone mineral density, but others have not. It is known that excess alcohol can damage bone, and that alcoholics are at greater risk of bone thinning and fractures. In a small study published in the Journal of the American College of Nutrition in December, the researchers looked at the effects of alcohol, caffeine and smoking on the bone mineral density of 136 post-menopausal white women between the ages of 57 to 89. The women responded to a survey asking about calcium, alcohol and caffeine consumption as well as their history of smoking and exercise habits. Women who consumed a moderate amount of wine, beer or liquor had a higher bone mineral density than those who did not drink. The average drink size was one beer or one glass of wine a day. Dr. Jasminka Ilich-Ernst, director of the Bone and Mineral Metabolism Lab at the University of Connecticut, told. "A small amount of alcohol actually promotes osteoblasts, or bone forming cells; on the other hand, alcohol also inhibits osteoclasts, which are bone resorption cells."  Bone is constantly making and replacing lost cells. In post-menopausal women the balance is off and bone formation declines because estrogen is no longer produced. Estrogen is a powerful stimulator of bone formation. In the study, calcium intake proved to be the most influential factor in bone mineral density. The women whose diets provided 750 milligrams (mg) of calcium or more a day had a higher bone mineral density overall, even if they were former smokers or coffee drinkers. "That amount of calcium attenuated the advanced effects of smoking and caffeine," said Ilich. But women with a history of smoking had lost more bone than women who never smoked. By maintaining an adequate calcium intake, "you probably can't reverse the effects completely and come to the bone mineral density level you had as a young person, but you can definitely slow down the bone loss," said Ilich. She recommends 1,200 mg of calcium a day for post-menopausal women, 1,000 mg a day for young adults and 1,300 mg daily for teenagers. Ilich notes that weight-bearing exercise actually increases bone mineral density, especially early in life. Strengthening the muscles puts pressure on the bones, which stimulates new bone growth. "Later in life exercise is also beneficial, but it's very hard to increase bone mineral density only with exercise," said Ilich. Women in the study who reported higher levels of past physical activity from the age of 18 had stronger bones, particularly if they were getting the right amount of calcium. "For older adults it is not necessary that they engage in high-intensity exercise, especially if they don't tolerate it well" said Ilich. "Ten to 15 minutes of activity like housework, gardening, walking or climbing stairs would be beneficial for them." SOURCE: Journal of the American College of Nutrition 2002;21:536-544.