The bitter truth: Sweeteners may lead to diabetes
PROMOTED as an aid to good health, artificial sweeteners may, in fact, be raising the risk of diabetes, said a study that urged a rethink of their widespread use and endorsement.
Called non-calorific artificial sweeteners (NAS), the additives are found in diet sodas, cereals and desserts - a huge market for people worried about weight gain and sugar intake.
Some experts recommend NAS for people with Type 2 diabetes, a disease that has attained pandemic proportions, and for a pre-diabetic condition called glucose intolerance, with elevated blood-sugar levels.
After leaving a sensation of sweetness on the tongue, NAS molecules pass through the intestinal tract without being absorbed. This explains why, unlike sugar, they add negligibly, if at all, to the calorie count.
But scientists reported in the journal Nature that experiments on lab mice and a small group of humans found NAS disrupted the make-up and function of gut bacteria, and actually hastened glucose intolerance.
"Artificial sweeteners were extensively introduced into our diets with the intention of reducing caloric intake and normalising blood glucose levels without compromising the human 'sweet tooth'," the study, led by Eran Elinav and Eran Segal of the Weizmann Institute of Science in Israel, said.
"Our findings suggest that NAS may have directly contributed to enhancing the exact epidemic that they were intended to fight.
"This calls for a reassessment of today's massive, unsupervised consumption of these substances," said Dr Elinav.
Independent commentators praised the work for its innovation, but warned against overreaction. The human trial involved just seven people over a week, and wider and longer trials are needed to draw any firm conclusion, they said.
"Human diets are complex, consisting of many foods, the consumption of which can vary in amounts, and over time," warned John Menzies of the Centre for Integrative Physiology at the University of Edinburgh in Scotland.
"This research raises caution that NAS may not represent the 'innocent magic bullet' they were intended to be to help with the obesity and diabetes epidemics," Nita Forouhi, a University of Cambridge epidemiologist told Britain's Science Media Centre.
"But it does not yet provide sufficient evidence to alter public health and clinical practice."