Millions of Americans guzzle diet drinks in order to protect their waistlines and themselves from the health problems caused by extra pounds.
But could this strategy backfire?
In one large new study, people who drank artificially sweetened beverages actually had a higher type 2 diabetes risk than those who drank water or other unsweetened beverages; fruit juice; or even regular sodas or other sugary beverages.
But don't spit out your diet drink just yet–scientific research is usually a work in progress. However, it is an interesting study, because although sugary drinks like soda have long been associated with a higher risk of diabetes, not as much research has been done on the diet versions.
In the new study in the American Journal of Clinical Nutrition, researchers analyzed diet diaries kept by 66,118 French women who were followed for 14 years.
They found diet-beverage drinkers consumed about 19 ounces a week, or less than two soda cans, while those who liked the sugary version consumed 11 ounces a week, or about one soda can. Compared to drinkers of unsweetened beverages (say, water), women who consumed sweetened drinks had a 1.3 times higher diabetes risk and diet-beverage drinkers had twice the risk. There was no link between type 2 diabetes and 100% fruit juice.
One take-home message of this study is that the French don't drink much soda, diet or otherwise. (Check out this map of soda consumption around the world; hands down, Americans consume the most.)
A Gallup poll last year found 48% of Americans drink soda every day, and soda drinkers have an average of 2.6 glasses a day. So the study doesn't shed light on the risks of heavy diet-drink consumption, if any.
However, some people have speculated that the sweet taste of aspartame or other artificial sweeteners could actually trigger a craving for more sweets. Although that's one theory, Joel Goldman, MD, chairman of endocrinology at Brookdale University Hospital and Medical Center in Brooklyn says he hasn't seen enough evidence to conclude that's true. People who veer towards artificially sweetened drinks may already have a predisposition towards sweets.
"People have a sweet tooth," says Dr. Goldman, who is also associate professor of clinical medicine at SUNY (State University of New York) Downstate Medical Center in Brooklyn. "They are probably going to be eating cakes and candies."
And it's possible that people who tend to like diet drinks–say, because they are already overweight–may be at greater risk of diabetes for other reasons. (The researchers found that body mass index, a measure of weight, did explain some, but not all of the diabetes risk.)
If that's the case, it would be hard to isolate diet soda or other diet drinks as the culprit. Having the condition known as prediabetes can also make you want sweet things, Dr. Goldman says.
Is drinking diet soda going to give you type 2 diabetes? Probably not.
"There are all kinds of possible explanations," says Dr. Goldman. "If it plays a role, it plays a very minor role compared to other things like eating all kinds of things you shouldn't like sugar and the genetics of diabetes."
On the other hand, Goldman points out, nobody is actually saying that artificially sweetened drinks are good for you either.
"If you ask anybody, they will be happy to tell you that the best thing is water, bottled water, tap water, Seltzer water," he said. "The question is, if you have a patient with diabetes who drinks a glass of diet soda, if that will keep him from eating a candy bar or drinking his coffee with sugar in it, I think that's beneficial in the long run."