When it comes to sweet foods, many weight-conscious consumers reach for diet or sugar-free options because they contain fewer calories. But according to a new review, regular consumption of artificial sweeteners like aspartame or stevia may have little benefit on the scale, and are actually linked to long-term weight gain, obesity and several cardiovascular health conditions.
Meghan Azad, lead author and professor of community health sciences at the University of Manitoba, conducted her review using 30 observational studies that included over 400,000 people with a median follow-up of 10 years, and seven randomized trials (the gold standard in clinical research) that included over 1,000 people with a median follow-up of six months.
Based on her results and the growing body of literature around the effects of artificial sweeteners, Azad cautions that sweeteners may not be a harmless alternative to sugar.
Weight management aside, Azad found that routine sweetener consumption was linked to higher rates of diabetes, high blood pressure and heart disease. Because the majority of evidence is based on observational studies, sweeteners may not be a direct cause, but there is still a potential for harm.
Azad believes that many factors are at play. From a psychological perspective, dieters who choose a sugar-free soda might compensate by eating more, shifting their calories elsewhere. This can be particularly destructive when justified as a reward for making a low-calorie choice.
There could also be biological responses to sweeteners as the body responds to the taste of the sweetener. Consumers could develop even greater cravings for sweeter foods, and a distaste for more nutritious foods that aren’t as sweet. Sweeteners may also affect metabolism, as the body expects sugar even in the absence of calories. They could also affect digestion by altering the gut microbiome: the collection of natural gut microbes that help keep us healthy.
Unfortunately, in today’s market, sweeteners may be difficult to avoid. They are hundreds of times sweeter than sugar, making them so widely used in processed foods that traces are even showing up in urine samples from people who report not consuming them. In other words, people are eating artificial sweeteners without even knowing it.
With obesity and heart disease on the rise, it makes a lot of sense for public health programs to promote lower sugar consumption, but not all sugar alternatives are equal. Even in the face of expanding waistlines, encouraging healthy eating needs to shift consumer and market focus away from calorie counts, as these can be deceiving.