A new artificial sweetener study links its use to possible long-term weight gain and an increased risk of a score of other problems, including obesity, diabetes, high blood pressure and heart disease.
The study, led by researchers from Canada's University of Manitoba and published in the Canadian Medical Association Journal, showed new data indicating that certain artificial sweeteners may have negative effects on such things as metabolism, gut bacteria, and appetite. Researchers cautioned, though, that "the evidence was conflicting."
Researchers completed a review of 37 studies that followed more than 400,000 people for an average of 10 years. Seven of the studies were randomized controlled trials involving 1,003 people followed for an average of six months.
"Despite the fact that millions of individuals routinely consume artificial sweeteners, relatively few patients have been included in clinical trials of these products," said Ryan Zarychanski, a study author at the university. "We found that data from clinical trials do not clearly support the intended benefits of artificial sweeteners for weight management."
Time magazine said the study echoed other studies that have suggested that sugar substitutes have little bearing on helping lose weight.
"Unfortunately, the quality of evidence that would support using sweeteners is not really strong," said Susan Swithers, a professor in the department of psychological studies at Purdue University, who has conducted such artificial sweetener studies. "I think we are at a place where we can say that they don't help."
Meghan Azad, the lead author of the study, said researchers at the university are now examining how artificial sweetener consumption by pregnant women may influence weight gain, metabolism, and gut bacteria in their infants.
"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," she said.