When was the last time you drank or ate something that contained an artificial sweetener (AS)?  I remember it well and my most striking recollection was the way it ‘hit the spot’ just like I would have expected sugar to, making me immediately suspicious of the effects it would have on my body.  It seemed implausible that it could mimic the taste/the sensation/the mood effects of a major sugar hit but not evoke any of the physiological responses of sugar…whether that be in my brain, my pancreas, my whatever!  We’ve been sold the concept that AS offer the western world an exit point from our collective march towards metabolic syndrome for decades but sweet relief (pardon the pun ;)), new scientific studies are piecing together the real impact of AS consumption.

“‘We found that artificial sweeteners may drive…an exaggerated elevation in blood glucose levels, the very same condition that we often aim to prevent by consuming them,’ Eran Elinav, MD, PhD, from the Department of Immunology at the Weizmann Institute of Science, Rehovot, Israel, said at a press briefing.” Medscape

There’s building evidence that from an appetite and brain perspective, AS intake, while reducing the kJ content of that actual item, encourages preferential selection of higher kJ foods and general over-consumption in both the short & long-term (Ferreira A, Generoso S, Teixeira A. Do low-calorie drinks ‘cheat’ the enteral-brain axis? Curr Opin Clin Nutr Metab Care. 2014 Sep;17(5):465-70. Hill S, Prokosch M, Morin A, Rodeheffer C. The effect of non-caloric sweeteners on cognition, choice, and post-consumption satisfaction. Appetite. 2014 Aug 13;83C:82-88).  So it’s not surprising then that there have been large studies linking AS consumption with impaired glucose tolerance – not as in people who are overweight and have diabetes are more likely then to choose AS containing products but in fact that the consumption of AS items precedes the glucose intolerance! Shock horror!

Much more mind-blowing than that is the new evidence from both animal and human studies suggesting that the effect is in part induced via changes in the microbiome of individuals consuming for example aspartame, sucralose and saccharin.  A thorough & well-designed study by Suez et al 2014 (Artificial sweeteners induce glucose intolerance by altering the gut microbiota) demonstrated that glucose intolerance didn’t occur in every animal or human consuming artificial sweeteners but what differentiated ‘responders’ from ‘non-responders’ was the bacterial population in their gut.  This theory was rigorously verified by the use of antibiotics (stopped the glucose intolerance) and fecal transplants (germ-free mice receiving fecal matter from humans who had demonstrated glucose intolerance secondary to AS consumption began to demonstrate glucose intolerance!)

Ultimately it’s another reminder about our individual responses to food and nutrition, a big part of which rests very much upon the shoulders of our mysterious microbiome….watch this space!

Medscape did a good overview of the Suez et al. paper that’s worth reading