Drinking cola may increase risk to women's bones

Drinking cola may increase risk to women's bones

Last Updated: Friday, October 6, 2006 | 6:49 PM ET
CBC News

Women who drink cola may be increasing their risk for low bone mineral density linked to osteoporosis, researchers say.

A study of 2,500 people concluded that drinking the carbonated beverages was linked with low bone mineral density in three different hip sites in women, regardless of age, menopausal status, calcium and vitamin D intake and use of cigarettes or alcohol.

Similar results were seen for diet pop and less strongly for decaffeinated pop.

In men, there was no link with lower bone mineral density at the hip, and both sexes showed no link for the spine.

The report by Katherine Tucker, director of the epidemiology and dietary assessment program at Tufts University in Boston, and her colleagues, appeared in this week's issue of the American Journal of Clinical Nutrition.

"The more cola that women drank, the lower their bone mineral density," Tucker said in a release.

"There is no concrete evidence that an occasional cola will harm the bones. However, women concerned about osteoporosis may want to steer away from frequent consumption of cola until further studies are conducted."

Calcium, phosphorus intake

While previous studies suggested cola consumption may be linked to poor bone health because it replaces milk in the diet, Tucker's study found that women who drink pop did not consume less milk than those who drink fewer colas.

But calcium intake from all sources, including non-dairy sources such as dark, leafy greens and beans, was lower among women who drank the most cola.

On average, men reported drinking five cola drinks a week, and women said they drank four. The average age of participants was just below 60.

No association was found between bone mineral density loss and consumption of other carbonated drinks.

Cola, but not other carbonated beverages, contains phosphoric acid. The ingredient could be responsible for the bone density link, but researchers don't understand how.

"Physiologically, a diet low in calcium and high in phosphorus may promote bone loss, tipping the balance of bone remodelling toward calcium loss from the bone," Tucker said, adding more controlled studies are needed to investigate the phosphorus link.

The soft drink industry says the drinks are not a major source of dietary phosphorus.

Osteoporosis is a condition that occurs when bone tissue thins or develops small holes. The condition can cause pain, broken bones and loss of body height.

Adequate calcium intake and regular weight-bearing exercise are recommended to prevent osteoporosis.