Aug. 23, 2001 -- If you are like most Americans, you've consumed countless colas and other carbonated beverages since having your last glass of milk. People down bottles, cans, and cups of the fizzy stuff all day long and often drink even more at mealtimes. There was even a marketing effort a few years ago to promote cola as a breakfast beverage.
The latest study finds no direct link between soft drink consumption and bone loss. The researchers warn, however, that the findings are not a license to chug the sweet stuff all day long. Although there is no single soda ingredient seeming to contribute to bone loss, problems still can happen if these beverages replace healthier ones.
Lead researcher Robert P. Heaney, MD, tells WebMD his team found nothing that specifically pointed to soda causing bone loss. "But somebody who is drinking six cans of cola a day and getting no milk at all is going to be in trouble," he adds. "It is not because they are drinking the cola. It is because they are not drinking milk."
Heaney and colleagues at Omaha, Nebraska's Creighton University, evaluated carbonated beverage consumption in a group of 30 women who routinely drank from two to seven, 12-oz cans of soda daily. They evaluated carbonated beverages -- with and without sugar and with and without caffeine -- water, and milk and found small but statistically significant increases the amount of calcium lost in the urine of people who consumed two or more caffeinated beverages each day. However, the calcium lost from the caffeine beverages is unlikely to lead to bone loss, Heaney says, because the body appears to be able to compensate for it.
In this study, a common component of colas and other soft drinks called phosphoric acid did not seem to affect the amount of calcium lost in the urine. Previous research had linked it with bone loss.
"I think this research shows that we can't condemn carbonated beverages," Heaney says. "I don't work for Coca-Cola, and they didn't pay me a penny to do this research, but the fact is that their product is not particularly harmful on the face of it. It is what it doesn't contain, like calcium, and not what it does contain that is the problem."
Connie Weaver, PhD, who heads the department of food and nutrition at Indiana's Purdue University, says children and adolescents have the most to lose by trading in milk and other calcium-rich foods for sugary soft drinks.
"You spend the first part of your life building up bone, and that is the most fruitful time to try and make a difference," she says. "If you build more bone when you are young, you are going to be more resistant to fractures later in life."
It is important for people of all ages to consume a calcium-rich beverage or food with every meal, Weaver says, whether it is milk, fortified orange juice, cereal, yogurt, cheese, or something else.
Parents often give up trying to influence food choices about the time their children hit their teens. But Weaver says adolescence is the most critical time of life for building strong bones.
"Parents often pick their battles with teens, and food doesn't seem all that important," she says. "Hopefully, their kids will make it through all of the other issues of adolescence without too many scars. But they will live with the diet choices and exercise patterns they set up for the rest of their lives."