Many of us think of diet soda as a way to have our soda and drink it, too. You get the experience of drinking soda, but not the calories and sugar that come with it. And while health experts aren’t exactly gung-ho about diet soda, researchers are still working to understand exactly what it does to the human body.
First things first: Drinking one to two cans of diet soda per day likely won’t hurt you — and contrary to popular belief, there isn’t credible evidence that diet soda causes cancer, although a possible connection is still being studied continuously.
But it can be helpful to know just how diet soda could be affecting your body in some not-so-great ways, especially if you’re a regular consumer of it. Here’s everything you need to know.
Diet Soda Could Contribute To Weight Gain
If you think diet soda can help you lose weight, you may want to think twice about that theory. Even though diet soda doesn’t contain sugar or calories, it can actually make you crave sugar. According to a 2021 study, beverages that are made with sucralose — a no-calorie sweetener used in many diet sodas — may stimulate appetite in some people. Another study found that the artificial sweeteners aspartame and saccharin are linked with an increase in appetite and an increased risk of obesity.
Additionally, an older study from 2010 found that aspartame and sucralose could increase sugar cravings.
Diet Soda May Increase Your Risk Of Heart Disease
There’s some research to suggest that diet soda could be detrimental to your heart health. “Diet sodas are often loaded with artificial sweeteners, which can have harmful effects on blood sugar levels and insulin sensitivity. In addition, diet sodas tend to be acidic, which can promote inflammation and contribute to heart disease,” explained Dr. Alice Williams, a physician.
Williams also noted that one study found drinking diet soda daily was associated with an increase in “vascular events” ― meaning vascular death, stroke and myocardial infarction.
Diet Soda Could Harm Your Gut Health
If you’re working to keep your gut health on track, you may want to be wary of diet soda. Nutritive sweeteners found in diet drinks, like polyols, could negatively impact your gut health, according to Divya Nair, the head of microbiology at probiotics company Sun Genomics.
“One study looked at the effect of polyols on both healthy and IBS patients,” Nair said. “Gastrointestinal symptoms were observed in both healthy individuals and irritable bowel syndrome (IBS) patients including symptoms such as bloating, abdominal discomfort, and laxative effects when consumed in healthy volunteers and patients with IBS.”
Diet Soda Could Cause Headaches
If you’re headache-prone, you may want to examine your diet soda habit. “Diet soda [often] contains caffeine, and caffeine can causes headaches in some people as it constricts blood vessels,” Williams said. “Additionally, caffeine is a diuretic, which can lead to dehydration, another possible cause of headaches.”
If you’re one of those people who gets headaches without caffeine, there is also some evidence that artificial sweeteners like aspartame and sucralose are correlated with headaches.
Diet Soda May Negatively Impact Brain Health
When diet sodas are consumed on a regular basis, they can have a detrimental impact on short- and long-term brain health, according to Dr. Annie Fenn, a physician, culinary instructor and founder of Brain Health Kitchen.
“In one of the most compelling studies to date, published in the journal Stroke, Boston University researchers analyzed the drinking habits of over 4000 healthy participants between 1998 and 2011,” she said. “After correcting the findings for confounding factors like age, sex, education, caloric intake, diet quality, physical activity, and smoking, the diet soda-drinking men and women ended up getting Alzheimer’s disease 2.89 more times and stroke 2.96 more times when compared to those who did not drink diet sodas.”
And the results show that the risks went up with each serving of diet soda consumed, she added.
Diet Soda Can Make Blood Sugar Stabilization Difficult
One small study published in August found that the artificial sweeteners sucralose and saccharin can interfere with the body’s insulin response.
“When an impaired insulin response plays out multiple times a day over years, it can lead to insulin resistance—meaning target organs (like your brain) no longer respond to insulin,” Fenn said. “The result? Glucose roams freely in the bloodstream, creating inflammatory particles that seep across the blood-brain barrier and damage the tiny blood vessels there.”
Diet Soda Could Decrease Bone Density
Diet sodas may be correlated with decreased bone density, due to the fact that diet sodas contain high levels of phosphates, which can leach calcium from bones, according to Williams. “As a result, regular consumption of diet soda may increase the risk of osteoporosis,” she said.
Additionally, one study found that intake of both regular cola and diet cola ― but not other carbonated beverages ― is associated with a lower bone mass density in women.
While this information may not be the best news for the diet soda drinkers among us, keep in mind that what diet soda actually does to the body is still being studied. But if you want to err on the side of caution, it’s probably best to keep your diet soda consumption on the moderate side.