Drinking lots of cola raises risk for osteoporosis

The next time you pick up a can of cola, think about your bones. That soda may be sucking minerals from your bones, increasing your risk of developing osteoporosis.

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“The more cola that women drank, the lower their bone mineral density was,” said Kathleen Tucker, director of the Epidemiology and Dietary Assessment Program at the Jean Mayer USDA Human Nutrition Research Center on Aging and a co-author of the research published in the October issue of the American Journal of Clinical Nutrition.

Nearly 55 percent of Americans, mostly women, are at risk for osteoporosis, the brittle-bone disease that causes bone fractures, according to the National Osteoporosis Foundation.

Tucker and her colleagues analyzed dietary questionnaires and bone mineral density measurements at the spine and three different places on the hip of more than 2,500 people in the Framingham Osteoporosis Study. In women, cola consumption was associated with lower bone mineral density at all three hip sites, regardless of their age, menopausal status, total calcium and vitamin D intake and whether they used cigarettes or alcohol.

However, cola consumption did not affect bone mineral density in the hips of men, nor was it associated with lower density in the spine for both men and women. Drinking diet cola produced similar results, and bone mineral loss was somewhat less for drinkers of decaffeinated cola.

The men reported drinking an average of five cola beverages a week, while the woman consumed four cola drinks. The serving size was defined as one bottle, can or glass of cola.

The study authors reported that “carbonated soft-drink consumption increased more than three-fold” between 1960 and 1990. They also noted that more than 70 percent of the carbonated beverages consumed by people in the study were colas.

While previous studies have suggested that cola contributes to bone mineral density loss because it replaces milk in the diet, the women in Tucker’s study who consumed higher amounts of cola did not drink less milk than women who drank fewer colas. The authors did conclude that calcium intake from all sources, including non-dairy foods such as dark leafy greens or beans, was lower for women who drank the most cola. On average, women consumed 1,000 milligrams of calcium per day, and men consumed 800 milligrams per day, both lower than the daily recommended 1,200 daily milligrams for adults over age 50.

Before you swear off cola altogether, Tucker says that “there is no concrete evidence that an occasional cola will harm the bones.” But, she adds, “women concerned about osteoporosis may want to steer away from frequent consumption of cola until further studies are conducted.”