Artificial sweeteners cut calories but may affect glucose control in obese: Study

The findings are a double-edged sword for individuals looking to shed weight and make health gains. The use of low-calorie sweeteners has grown in popularity and is associated with reductions in caloric intake and body weight .

However, this study seems to suggest that the consumption of the artificial sweetener aspartame may be associated with greater glucose intolerance, particularly for those with obesity.

Considering the public health importance of obesity and its consequence, the role of diet in obesity and the cost spent on non-caloric sweeteners, little clinical research has been carried out in this area.

One systematic review on the effect of sweeteners on glycaemic response found no association in observational studies that looked at low-calorie sweetener intake, body weight and fat mass. However a small positive association with BMI was found.

Study details

The study took data from 2,856 US adults from the Third National Health and Nutrition Survey (NHANES III).

Individuals recorded details of their diet over the past 24 hours and were placed in groups of artificial sweetener consumers (aspartame or saccharin), or high/low consumers of natural sugars (sugar or fructose).

Diabetes risk was measured as the ability to manage blood sugars using an oral glucose tolerance test. 

Results indicated that aspartame intake significantly influenced the association between body mass index (BMI) and glucose tolerance.

Those reporting aspartame intake had a steeper positive association between BMI and glucose tolerance than those reporting no aspartame intake. This adverse effect was not found in those consuming saccharin or natural sugars.

"Our study shows that individuals with obesity who consume artificial sweeteners, particularly aspartame, may have worse glucose management than those who don't take sugar substitutes," commented Professor Jennifer Kuk, obesity researcher at York University's Faculty of Health.

The team stressed the need for more research to better understand the weight-management benefits of artificial sweetener consumption over natural sugars against the potential increased diabetes risk, particularly for those with obesity.

What little research has been conducted into the long-term health benefit of low-caloric sweeteners has proved inconclusive particularly when changes in body weight are considered.

Attempts to explain aspartame’s effect on the human body pointed towards associations with changes in gut microbiota. These changes in turn associated with impairments in insulin resistance in lean and obese rodents.

“We observe that aspartame was related to significantly greater impairments in glucose tolerance for individuals with obesity, but not lean individuals. In fact, our results suggest a beneficial effect of aspartame in lean individuals,” the study commented.

The authors believed the lack of lean individuals in the population who reported consuming aspartame meant this observation required further investigation.

Industry Response

The industry has been vocal in the past about the benefits, as well as limitations, that artificial sugar substitutes can offer to the consumer.

In response to a report that claimed artificial sweeteners might not help reduce obesity in children, the International Sweeteners Association said that low calorie sweeteners were not a silver bullet but a tool that could indeed help in the reduction of energy intake and subsequently, weight loss.

“They provide consumers with the choice and the ability to make smart swaps by replacing higher calorie foods and drinks with a lower calorie option and to enjoy sweetness as part of a calorie controlled diet and balanced lifestyle. They are safe for consumption,” it said.