Learning About Osteoporosis
by Patrick McCarty
Osteoporosis is a bone disease that affects millions of Americans as they age. At around age 32 we reach our maximum adult bone mass. After this our bones absorb less calcium and begin degenerating. Menopause speeds up this process. In people who suffer from osteoporosis, this process becomes so advanced that bones fracture easily, leading to sometimes life threatening debilitation.
Dietary protein increases urinary calcium losses and has been associated with higher rates of hip fracture. This phenomena has been observed in many cross-cultural studies. (Such bone fracture rates are considered a barometer of overall bone strength and health). Now a study of 85,900 women reported in American Journal of Epidemiology (1996;143:472-9) has found that protein was associated with a 22 percent increased risk of forearm fractures for women who consumed more than 95 grams per day compared with those who consumed less than 68 grams per day. (The Recommended Dietary Allowance of protein for women is 50 grams per day.) This increased risk was observed for animal protein only, not for women eating larger-than-recommended quantities of vegetable protein. For this and other reasons, soybeans may make it possible to stop bone breakdown, and even increase bone strength, despite age.
Researchers also calculated that women who consumed at least 5 servings of red meat per week had a 23 percent increased risk of forearm fracture compared with women who ate red meat less than once per week.
With consideration of the above mentioned information, in the American culture where protein is considered king, we can expect high rates of osteoporosis.
The Value of Soy
Although weak estrogenic activity is found in whole foo
ds such as grains, vegetables, legumes, nuts and seeds, soy is the only food that contains sufficient amounts of active components to approximate the effects of estrogen. Soybeans are rich in isoflavones. There are several different kinds of isoflavones in soybeans. Diadzein and genistein are the two soy isoflavones of interest to osteoporosis researchers. Additionally, these two elements have been shown to reduce the severity of hot flashes and even promote the growth of vaginal cells, counteracting the tendency of this tissue to thin after menopause.
The possible link between soy isoflavones and women's health has been noted. In Japan, where soy consumption is much higher than in the United States, women report fewer menopausal symptoms. Japanese women also live longer and have fewer cases of osteoporosis and heart disease.