Research showing that sugar consumption may fuel the obesity epidemic has triggered the upsurge in popularity of non-nutritive sweeteners (artificial sweeteners), such as aspartame, stevioside, and sucralose. In fact, in 2008, more than 30 percent of U.S. adults consumed artificial sweeteners daily, and this proportion is on the rise.
Emerging evidence indicates that artificial sweeteners may have an adverse effect on metabolism, gut bacteria, and appetite. What is more, studies suggest that chronic exposure to artificial sweeteners may result in increased food consumption and weight gain.
According to the Academy of Nutrition and Dietetics, artificial sweeteners can be used as a strategy to manage weight or blood sugar by helping to limit energy intake. However, artificial sweetener consumption has been correlated with weight gain and obesity.
Dr. Ryan Zarychanski and Dr. Meghan Azad, assistant professors of the Rady Faculty of Health Sciences at the University of Manitoba, and colleagues aimed to determine whether regular artificial sweetener consumption is associated with adverse long-term effects on weight and heart disease. Their research was published in CMAJ.
The team conducted a systematic review that included 37 studies that followed more than 400,000 individuals for around 10 years. In total, seven of the studies were randomized controlled trials, which are considered the gold standard in clinical research. The randomized controlled trials followed 1,003 people for around 6 months.
Artificial sweeteners linked to weight gain
The randomized controlled trials with a short follow-up period indicated that intake of artificial sweeteners is not consistently linked to a decrease in body weight, body mass index (BMI), or waist circumference.
In the longer observational studies, however, findings pointed toward a significant association between consumption of artificial sweeteners and increases in measures of body weight, BMI, and waist circumference.
Moreover, the researchers reported a link between artificial sweetener consumption and a higher risk of obesity, high blood pressure, type 2 diabetes, stroke, and heart disease. The authors note that there is no data available from randomized controlled trials to confirm these observations, however.
"Despite the fact that millions of individuals routinely consume artificial sweeteners, relatively few patients have been included in clinical trials of these products. We found that data from clinical trials do not clearly support the intended benefits of artificial sweeteners for weight management."
Dr. Ryan Zarychanski
Lead author Dr. Azad follows on by saying, "Caution is warranted until the long-term health effects of artificial sweeteners are fully characterized." Dr. Azad and her collaborators at the Children's Hospital Research Institute of Manitoba are researching how consumption of artificial sweeteners by women in pregnancy may influence their infant's weight, metabolism, and gut bacteria.
"Given the widespread and increasing use of artificial sweeteners, and the current epidemic of obesity and related diseases, more research is needed to determine the long-term risks and benefits of these products," Dr. Azad concludes.