I wasn’t planning on writing another piece on nutrition science for a while, but then along came an artificially-sweet spider: New York Times published an op-ed called “The Evidence Supports Artificial Sweeteners Over Sugar” and it blew up social media. Full disclosure, I shared it without reading it carefully, intending to go back to it later. As I’ve mentioned before, I like picking fights about science almost as much as I like the science itself, and I figured this was a good way to get some discussions going. Now that I’ve had a chance to read the article, and read some of the rebuttals to it, let’s break it down and look at what’s going on.
First, I have to give props to the author, Aaron E. Carroll, a pediatrics professor at Indiana University School of Medicine, for making one point with which I unequivocally agree:
“[Artificial sweeteners] have, for decades, been attacked as harmful chemicals. But everything is a “chemical,” and not all of them are bad for us.”
This is a great point, and one I cannot emphasize enough: calling a food a “chemical” is meaningless nonsense.
However, here is Carroll’s central thesis:
“The available evidence points to the fact that there appears to be a correlation between sugar consumption and health problems; none can be detected with artificial sweeteners.” (emphasis mine)
Obviously, Professor Carroll has not seen Revenge of the Sith, or he would know that only a Sith speaks in absolutes. This thesis is not saying there is less of a risk, or that the risk of artificial sweeteners has been overstated, it says that artificial sweeteners have absolutely no health drawbacks whatsoever. Let’s take this statement apart a bit, and dig in to the problems of sweeteners.
The primary focus of the article is the idea that the risk of cancer or other neurological diseases as a result of artificial sweeteners (in this case, saccharin or aspartame) has been overstated. This is actually true, as described by the National Cancer Institute (NCI), part of the National Institutes of Health (NIH). The primary source of concern here is studies in the early 1970s, which indicated that saccharin caused bladder cancer in lab rats. These results were so compelling, Congress mandated cancer warnings on all food products containing saccharin. However, epidemiological studies show no correlation between saccharin and bladder cancer in humans, and the mechanism that caused bladder cancer in the rats does not apply to humans. Due to this new evidence, Congress overturned the warning mandate in December 2000. Aspartame followed a similar pattern, but instead of cancer concerns coming from an actual study, concerns came from a rhetorical question in a single article that attempted to use aspartame to explain trends in brain tumor rates. No actual conclusive cancer risk has ever been found from aspartame. Other artificial sweeteners have been approved for use by the FDA after over 100 individual studies on safety were conducted.
This is not to say that artificial sweeteners have no side effects whatsoever. Recent studies have shown that artificial sweeteners can alter the intestinal microbiome, causing glucose intolerance and other metabolic effects. This can lead to an increase in food cravings, specifically having a “sweet tooth”, which in turn can lead to higher risks for obesity and Type 2 diabetes. While the exact mechanism by which the microbiome is affected remains unknown, multiple studies show similar correlations. However, added sugar — in any form — can lead to higher risk of obesity and Type 2 diabetes. Having a beverage sweetened with added sugar can add 200-300 calories to your daily consumption, whereas artificial sweeteners add no calories but can lead to metabolic changes causing food cravings and, in turn, higher caloric consumption.
What can we make of all this? First off, making an overly precise thesis is bad science, and the New York Times article is extremely misleading. However, it is on point that the risks of artificial sweeteners, particularly as related to cancer, have been overstated. But added sugar of any kind, whether natural sugar or artificial, can increase risks of obesity and Type 2 diabetes. Like anything else, I recommend that you know the risks and make your own choices. However, the best thing you can do is to avoid food that has any added sugar, regardless of the source of the sugar. Instead of worrying about where the sugar comes from, worry instead about where it’s going.