In recent years, expert opinions on things once considered unhealthy, such as eggs, meat and dairy, have changed to embrace foods previously scorned. Now, one doctor says yet another item we’ve been told to avoid actually isn’t that bad: diet sodas.
Aaron Carroll, MD, professor and leading pediatric researcher at the Indiana University School of Medicine, takes a provocative stance in his new book “The Bad Food Bible: How and Why To Eat Sinfully”, arguing that the occasional Diet Coke isn’t so bad, and that it’s better than the real thing.
“When you’re going to have a soda once in a while, I would choose the artificial sweetener,” Carroll tells The Post. “And I would make the same choice for my kids.”
‘If there is a danger, it’s incredibly small.’
He spends a great deal of one chapter discussing Diet Coke and why it might not be so bad. He says the real danger is sugar — which has been strongly linked to diabetes and obesity. Artificial sweeteners, on the other hand, have not been proven to be harmful to humans, he argues.
Carroll was completely unprepared for the backlash and scrutiny he experienced after first writing on the subject in a 2015 New York Times column.
“There were people who thought that I should have my [medical] license revoked [and] people who questioned why I hadn’t had my children taken away from me.” One California-based reader went so far as to invoke open-records acts in Indiana to go through his e-mail. “They were convinced I’d been paid off,” says Carroll.
He hadn’t been. He just believes the notion that artificial sweeteners are the enemy is misguided — and often perpetuated by the misinterpretation and misrepresentation of scientific studies.
For example, just because artificial sweeteners have been shown to increase the likelihood of bladder cancer in second-generation rats (meaning the offspring of rats that actually receive high doses of sweeteners), it doesn’t mean they have the same effect on humans.
“If you give rats a lot of things, they get bladder cancer, including things like vitamin C,” says Carroll.
And history proves his point: “Billions of people are drinking [artificial sweeteners], and we’re not seeing increased rates of bladder cancer,” he says.
There’s also the public’s perceived reluctance to ingest anything deemed a “chemical.”
“We get worried about what’s a chemical and what’s not — [but] everything’s a chemical,” he says. “People [are] concerned that these are chemicals made in a lab, so they must be dangerous.” But that’s just not the case, according to Carroll, who says trials on the subject haven’t shown artificial sweeteners to be a public health threat.
“If there is a danger,” he says, “it’s incredibly small.”
But not every expert shares Carroll’s views.
Susan Swithers, Ph.D., a professor of behavioral neuroscience and lead researcher on the effects of artificial sweeteners at Purdue University, suggests that people avoid Diet Coke and similar products.
While she agrees that “a [diet soda] every two weeks … probably doesn’t matter,” she cites studies in humans that show links between the regular ingestion of artificial sweeteners and unhealthy conditions such as Type 2 diabetes, high blood pressure, strokes, dementia and obesity.
But even these data sets can’t definitively prove artificial sweeteners are to blame: “With the human data, we can’t make causal attributions because they’re not experimental studies — they’re observational studies,” she admits.
But while research hasn’t directly linked artificial sweeteners with these conditions in humans, she says there is plenty of evidence from animal studies that suggests there are “mechanisms” that could hypothetically lead to these negative outcomes.
“The best data we have says that the diet soft drinks don’t reduce your risk for these outcomes, and potentially increase your risk.”
‘When you’re going to have a soda once in a while, I would choose the artificial sweetener. And I would make the same choice for my kids.’
Swithers is especially concerned that overly sweetened foods and beverages might be warping children’s perception of what’s healthy.
“When we introduce these sweetened beverages to kids, they no longer recognize what food is supposed to taste like,” she says, “And we set them up … to have this ongoing battle with what healthy food should look and taste like.”
There are several kinds of artificial sweeteners, with the most well-known being saccharin (Sweet’n Low), sucralose (Splenda) and, of course, Diet Coke’s aspartame. According to Swithers, how the sweetener is processed by the body all depends on its chemical makeup, with some sweeteners not metabolizing at all: “We consume it and it just passes through,” she says. But aspartame might have a lasting effect on the body even if it isn’t metabolized.
“Some [studies] suggest that the metabolic byproducts [of aspartame] could be one of the things that changes the gut microbiome,” says Swithers. Such changes could leave the body less able to regulate blood sugar levels, potentially contributing to diabetes.
But both experts can agree on one thing. Consuming 12 Diet Cokes every day — as it was recently reported that President Trump does — isn’t healthy.
Carroll says: “I wouldn’t recommend it, but that’s just because I wouldn’t recommend too much of anything.”