The Great Diet Soda Debate

The Great Diet Soda Debate

To many weight loss enthusiasts, diet soda is the nutritional equivalent of getting away with murder, a naughty indulgence to be enjoyed without fear of repercussion or, more importantly, weight gain. Some “experts” even go so far as to say diet soda can be a valuable weightless tool.

But are Coke Zero and Diet Pepsi truly the nectar of the gods? Truth is, it’s hard to say. Unlike with trans fat, there is no hard and fast evidence showing that diet soda rots your insides. However, there’s also no credible evidence showing that it benefits you. There are, however, plenty of studies indicating that diet sodas are, in a word, weird. Whether it might cause heart disease, or it might make you eat more junk food, or it might give you cancer, the big question about diet soda is: is it worth it?

A little history
Diet soda bubbled into popular culture in 1952 when Kirsch Beverages of Brooklyn, New York came out with No-Cal Ginger Ale, a saccharine-sweetened drink aimed at diabetics. In 1962, Royal Crown came out with Diet Rite Cola, this time sweetened with saccharine and cyclamate. Coca-Cola rolled out Tab in 1963. Pepsi followed suit in 1965 with Diet Pepsi. And the race was on.

In 1970, the artificial sweetener cyclamate was banned in the United States when it was found to cause cancer in lab rats. In 1977, saccharine came under scrutiny for the same reason. In the 1980s, soft drink manufacturers switched to aspartame. Today, while most diet sodas still contain aspartame, some—Diet Rite and Hansen Natural Sodas—use sucralose, aka Splenda. Others such as Coke Zero and Diet Red Bull throw a little acesulfame potassium into the mix. When the legitimacy of the saccharine/cancer connection came into question in the 1990s, saccharine-sweetened Tab returned to the market.

Some sweet science
If you’re wondering which of these sweeteners are good and which ones are toxic, the answer is hazy at best. For example, one minute saccharine kills on contact, the next minute it’s harmless. Science gets even more wobbly for the other sweeteners, given that most of them have only been around for a few decades. That’s not much, considering it took almost a century for anyone to figure out saccharine’s potential health-risk issues.

Nothing for something
A far more obvious concern with diet drinks is that people think they’ve somehow cheated the system when this is most likely not the case. A study by the University of Alberta published in the August 2007 issue of the journal Obesity found that feeding a diet of low- and zero-calorie food to young lab rats tampered with the body’s ability to recognize calories and regulate food intake, so that later in life, the rats tended to overeat, even highly caloric foods.

Granted, these are rats, not people, so the rules are very different, but this is still food for thought, so to speak. How many times have you ordered diet soda at the movies, thinking that it somehow made the accompanying giant tub of buttered popcorn acceptable? Because you passed on a 150-calorie drink, you’re now “allowed” to eat a 400-plus-calorie fatty snack? Hmmm.

In fact, a 2005 study by the University of Texas Healthy Science Center showed that there’s a 41 percent increased risk of being overweight for every can of soda a person consumes in a day. While the popcorn theory isn’t the proven reason for these findings, it is a definite possibility. Another plausible theory is that diet sodas alert the body of a possible influx of calories without delivering the goods, causing further calorie cravings.

Backing up this study is a July 2007 study by the Boston University School of Medicine. When 6,000 middle-aged men and women were observed over four years, it was found that those who drank one soda or more a day had approximately a 50 percent greater risk of metabolic syndrome—a group of risk factors including excessive fat around the middle section of the body, low HDL (good) cholesterol, high blood pressure, and other health-risk symptoms.

On the other side of the fence, there’s been research trickling in claiming diet soda can work as a diet aid. But don’t get too excited, the studies aren’t that impressive. For example, a study earlier this year in the journal Obesity claimed that artificial sweeteners promoted weight loss. The study compared people drinking water versus people drinking diet soda on a 12-week weight loss program. The soda sippers lost slightly more weight (about 4 pounds, on average).

First of all, you can’t judge the long term health benefits of anything in 12 weeks. Secondly, the study didn’t count calories, therefore the weight loss probably occurred due to increased satiety in the soda drinkers. That’s great, but in order to maintain weight loss, that means they would need to keep drinking diet soda indefinitely to keep from craving more real food. So basically, this weight-loss technique establishes a psychological addiction to a substance for which the long-term health benefits are still in question.

But seriously…
Of course, it’s easy to explain most of the health-related research away with chicken-and-egg logic. Is diet soda making people unhealthy, or are unhealthy people drawn to diet soda in a misguided attempt to turn things around?

And while we’re debunking anti-diet-soda theories, it’s worth noting that, contrary to popular advice (including, in the past, my own), carbonation does not pull calcium from your bones. According to a report in the American Journal of Clinical Nutrition in 2001, the calcium problem only occurred when the carbonated drinks also contained caffeine.

But these two concessions are small potatoes compared to the overwhelming, ever-increasing body of research suggesting that diet sodas are problematic. True, none of the evidence is entirely conclusive and even the researchers involved are quick to admit that their studies need to be taken with a grain of salt. But, at the same time, every time you open a can of Diet Coke, there’s a giant question mark floating among those bubbles. You don’t really know what you’re drinking and you have no idea what it’s doing to your body. It’s up to you to decide, if it’s really worth it when you could have brewed yourself an iced tea (without sugar, of course)?