14 DAY TRIAL // About 55 % of Americans, mostly women, are at risk of developing osteoporosis, a disease characterized by a demineralization of the bones, which become porous and fragile, this causing a higher susceptibility to fractures.
Katherine Tucker, PhD, director of the Epidemiology and Dietary Assessment Program at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, and her team found that cola may contribute to the bone demineralization in older women. The scientists analyzed dietary questionnaires and bone mineral density measurements at the spine and three different hip sites of a study sample of more than 2,500 people with an average age just below 60.
Regardless of factors such as age, menopausal status, total calcium and vitamin D intake, consume of cigarettes or alcohol, cola proved to be linked to a lower bone mineral density in women at all three hip sites. In men, cola was not linked with lower bone mineral density at any bone site and in women' spine neither. The negative results found in women were not dependent on the type of cola (normal, non sugar, decaffeinated, even if in this case were a little weaker).
The research reported a consumption average of five cola drinks per week for men, and four for women. "The more cola that women drank, the lower their bone mineral density was," says Tucker, who is corresponding author of the study.
"However, we did not see an association with bone mineral density loss for women who drank carbonated beverages that were not cola."
"Carbonated soft-drink consumption increased more than three-fold between 1960 and 1990,' cite the authors.
The researchers noticed that all cola drinks contain phosphoric acid, not found in non cola carbonated drinks. They determined that women who consumed higher amounts of cola did not have a lower intake of milk than women who consumed fewer colas.
Anyway, the team determined that the women who drank more cola had a lower calcium intake from all sources, including non dairy sources. The daily calcium intake was 1,000 mg for women and 800 mg for men, both less than 1,200 mg daily recommended for adults over age 50.
"Physiologically, a diet low in calcium and high in phosphorus may promote bone loss, tipping the balance of bone remodeling toward calcium loss from the bone. Although some studies have countered that the amount of phosphoric acid in cola is negligible compared to other dietary sources such as chicken or cheese," Tucker says, "further controlled studies should be conducted to determine whether habitual cola drinkers may be adversely affecting their bone health by regularly consuming doses of phosphoric acid that do not contain calcium or another neutralizing ingredient."
Scientists forewarn that, for the moment, the results should be taken with caution. "We are not certain why women who drank more cola also had lower bone mineral density," says Tucker.
Also the higher amount of cola consumption was linked to a lower consumption of fruit juice. Many studies proved that low fruit and vegetable intake may affect bone mineral density. Nutritional choices can affect bone health, but "there is no concrete evidence that an occasional cola will harm the bones," says Tucker.
"However, women concerned about osteoporosis may want to steer away from frequent consumption of cola until further studies are conducted."