IN SHOCKING REVERSAL, NATION’S SCIENTISTS DECLARE THAT CORRELATION DOES, IN FACT, PROVE CAUSATION!
A couple of studies on artificial sweeteners presented at the American Diabetic Association’s Scientific Sessions in San Diego last week are being hailed as new evidence that diet soda can make you fat. For example, under the headline “2 New Studies: Diet Soda Leads to Weight Gain,” the blog Fooducate declares:
Not only will diet soda NOT help you lose weight, it may actually cause weight gain and diabetes!
Study #1 tracked the waist circumference and diet soda consumption of 474 people between the ages of 65 and 74 over an average of 3.5 years. In general, everyone got fatter between their baseline and follow-up appointments, but diet soft drink “users” got 70% fatter than “non-users.” Frequent users (those who consume more than 2 diet sodas per day) got significantly fatter: their waists grew, on average, 500 percent more than non-users.
What’s that? A correlation, you say? Why, the only possible explanation is that the variable randomly assigned to the x axis must have caused the differences in the variable plotted on the y-axis! It’s SCIENCE!
Sorry, soda lovers – even diet drinks can make you fat. That’s the word from authors of two new studies, presented Sunday at a meeting of the American Diabetes Association in San Diego.
Bad News, Your "Diet" Soda Is Making You Fat Too
More bad news, diet soda drinkers: data presented recently at the American Diabetes Association’s (ADA) Scientific Sessions suggest that diet drinks may actually contribute to weight gain and that the artificial sweeteners in them could potentially contribute Type 2 diabetes.
Because there’s no chance there’s some confounding factor, or that the causal arrow points in the other direction. After all, people who are getting fatter wouldn’t have any reason to be more likely to drink diet soda, would they?
The study’s authors are somewhat more modest about what their research shows:
“These results suggest that, amidst the national drive to reduce consumption of sugar-sweetened drinks, policies that would promote the consumption of diet soft drinks may have unintended deleterious effects.”
However, it still seems irresponsible to me that they claim their research shows that diet soft drinks have “effects,” deleterious or otherwise. Correlations are not effects. All they’ve shown is that, in general, people over 65 are more likely to consume “diet” drinks if they are also gaining more weight. Which is not especially surprising, if you think about it.
I wish people who write headlines and story leads like the ones quoted above would have “Correlation =/= causation” tattooed across their foreheads, backwards, so they’d be reminded of it every time they look in the mirror.
Study #2 and more incredulous owls below the jump:
20 MICE WHO ATE ASPARTAME SHOWED SOME POTENTIAL EARLY SIGNS OF DIABETES (MAYBE). ALSO, SIGNS OF DEATH.
Study #2 involved 40 mice, half of whom were fed chow + corn oil and half of whom were fed chow + corn oil + aspartame (6 mg/kg/day, which seems to be approximately equivalent to a 132 lb person drinking 20 oz of aspartame-sweetened soda per day). After three months on the diets, the mice on the aspartame diet had fasting glucose levels 37% higher than the mice only getting chow + oil. The fasting insulin levels in the aspartame-fed mice were also 27% lower, but that wasn’t statistically significant.
I’m not sure how biologically significant 37% higher average fasting glucose is, or what the range for each group was, or whether the aspartame-fed mice went on to develop diabetes. The latter is especially hard to answer because apparently, by 6 months after starting the diet, at 18 months of age, only 50% of the aspartame-fed mice and 65% of the control group mice were still alive—which, the researchers note, was not a statistically significant difference and is apparently about par for the course with mice, whose average lifespan seems to be between 1-2 years.
This study is intriguing, and does offer one possible mechanism by which aspartame could independently cause weight gain—if aspartame consumed in sufficient quantities has a biologically meaningful effect on blood sugar levels, then diet sodas could indeed be causing people to store more fat than they would if they consumed another calorie-free beverage. But this is far from a smoking gun. It’s not clear if all artificial sweeteners have the same effect. Or if it would also occur in mice not eating a high-fat diet. Or if the blood sugar effects only happen above a certain level of aspartame consumption. Or if it works the same in humans. Or if it does lead to diabetes or negative health outcomes or just produces some biological markers of pre-diabetes. And what this study also showed was that rats who eat aspartame are not significantly more likely to die early than rats who don’t eat aspartame.
BUT WAIT I HAVE MORE CORRELATIONS FOR YOU
Fooducate has one more piece of evidence to submit—the clincher, it seems, if you’re still not convinced by those two studies that diet sodas make you fat:
Still sipping away at your Diet Sprite?
Need more evidence that drinking diet soft drinks is bad for you?
Consider this – ever since diet soft drinks were introduced into the market, obesity and diabetes rates in this country have skyrocketed.
Consider this—ever since aerobics became a nationwide trend, obesity and diabetes rates in this country have skyrocketed! Consider this—ever since sushi became popular in America, obesity and diabetes rates have skyrocketed! STOP DOING AEROBICS AND EATING SUSHI. FOR THE LOVE OF GOD, THINK OF THE CHILDREN.