Hop on Pop: Carbonation and Bone Health

I don’t drink soda or allow my kids to have it because I’ve known for years about how bad it is for teeth and bones. I know sugar is the biggest culprit, but when I tell people that the carbonation is nearly as bad because it leaches calcium from your bones, they argue with me. A friend of mine who drinks mostly plain sparkling water says I’m completely batty – who’s right on this?
– Kris

I assume your friend thinks you’re batty because of your beverage opinions and not for other reasons beyond my expertise. Given that, I’d have to side with your Perrier-drinking pal, but also assure you that it is a common misconception that carbonation pulls calcium from your bones. However, to avoid giving him more ammunition, you should probably refrain from also cautioning him against Fizzy Lifting Drinks, like those once served to an unsuspecting Grandpa Joe in a now famous Chocolate Factory (“Atta boy, Charlie, keep burping!”).

Carbonation’s one known attribute is that it speeds the absorption of alcohol into the blood, making your gin and tonic more helpful in producing a big tip for the waitress. Other than that, the little bubbles are harmless. It’s actually the phosphoric acid that many sodas contain, and possibly the caffeine, which have consequences for the calcium levels in the body. In general, only dark cola drinks contain both phosphoric acid and caffeine, while the iridescent green ones have just caffeine, and the clear citrus sodas and seltzers include neither.

The negative effect of phosphoric acid on bone health is pretty well established, especially in children. Quite a bit of research has concluded that cola drinks consumed by kids seriously increase the likelihood of fractures, while consumption of non-cola carbonated beverages do not. Most of this research was done on pre-teen or teenage girls and the effect was considerable even when consumption was less than one cola per day. Toward the other end of the time-line, similar studies of postmenopausal women have almost equivalent findings. The issue of caffeine versus calcium levels, however, is not quite so clear-cut – and the stimulant may not even be a factor in kid’s bone health. Some investigators have concluded that since soda often replaces milk in the child’s diet, lowered calcium intake is the bigger problem. That could change if the dairy industry abandons the lame milk mustaches on B-list celebrities and begins work on lunchbox-sized cartons with built-in mp3 players.

For kids, the problem is compounded by the nearly quarter cup of sugar in a 12 oz. soda. Their teeth get a one-two punch – first an acid bath to soften up the enamel, then a nice coating of liquid sugar. Together, they make plaque bacteria happier than Star Jones on a cruise ship – plenty of nooks to settle into and an all-you-can-eat buffet. In addition, as the bacteria process the sugar, even more tooth-destroying acid is produced. With soft-drink companies signing lucrative marketing contracts with financially strapped school districts, they’ve got a captive audience for their bright and shiny vending machines. It’s a wonder that any teeth at all are visible in high-school graduation photos.

Certainly seltzers and sparkling waters make an excellent option to sugary sodas, but more often than not, they are an acquired taste. A more palatable alternative can be natural sodas found in health food stores and some supermarkets. These get their bite most often from citric or ascorbic acids rather than phosphoric acid. The major drawback is their sweetener, whatever the name – fructose, honey, juice concentrate, rice syrup or barley malt – is still basically sugar and provides nothing but calories and plaque fertilizer. Diet drinks are not much better; cola flavors usually contain both phosphoric acid and caffeine and the artificial sweeteners have their own set of issues. With compromise as a goal, a spoonful of frozen fruit juice concentrate in a glass of seltzer might keep the kids happy (and it’s easier than home schooling).

I hope giving you a qualified OK for carbonated drinks opens a whole new beverage category for you, and an occasional soda won’t harm your children either. I suspect your kids aren’t nearly as demanding as was Veruca Salt in Mr. Wonka’s factory, but if in their teenage sugar-lust they also beg for Everlasting Gobstoppers and Fizzy Lifting Drinks, go ahead and give in. Just save burping for homeroom where it belongs.

Dr. Ed Rabin is a chiropractor practicing at Life Chiropractic Center in Boise. Send your health-related questions to theantidote@edrabin.com (on the Web at www.edrabin.com).