Brain 'not fooled' by sweeteners1st September 2009
The brain does not appear to be fooled by artificial sweeteners designed to mimic the taste of sugar, according to a new study in the Netherlands.
Using a brain scanning technique called functional magnetic resonance imaging (fMRI), researchers observed the ways peoples’ brains responded when they ingested four different artificial sweeteners mixed as a cocktail.
The four sweeteners contained in the cocktail were aspartame, acesulfame K, cyclamate and saccharin.
They were mixed in proportions that researchers said would help them to mimic the taste of sugar.
Subjects drank orange drink sweetened with sugar and the four sweeteners on alternate days, so that the two tastes would become less distinct in their minds.
Paul Smeets, a neuroscientist at University Medical Center Utrecht and the leader of the study, said that when the drinks were administered on alternate days, the subjects were unable to tell the difference between their tastes.
However, even though the subjects reported not knowing which drink was which, the fMRI scans showed different brain activity depending on which sweetener was ingested.
And whereas the artificially sweetened orange drink only activated the amygdala, the drinks flavoured with sugar activated both the amygdala and the caudate nucleus.
The caudate nucleus is a region of the brain involved in learning and memory, whose activity in the study subjects Smeets surmises represented an unconscious estimate of caloric value.
Smeets said that his team believes the brain can distinguish between a caloric and a non-caloric sweet drink, even if people cannot.
The study raises questions about how useful artificial sweeteners are for people who are on a diet, in line with conclusions some studies have drawn that artificial sweeteners do not reduce calorie consumption.
Some studies have shown that drinking diet soft drinks or other artificially sweetened beverages can actually stimulate appetite and food consumption, while others have shown that this only occurs in people who do not drink the beverages regularly.
Guido Frank, a psychiatrist who studies brain responses to sweeteners at the University of Colorado at Denver, said that if people could manage to replace all of their sugared drinks with a combination of a glass of water, a can of diet soda and three carrots, that would be one example of a good dietary routine.
He said that instead, people could argue that using large amounts of artificial sweeteners is not helpful for people on a diet because the brain cannot be tricked.
Smeets said he was unsure if an artificial sweetener would ever truly fool the body’s response system.
Share this page
There are no comments for this article, be the first to comment!
Post your comment
Only registered users can comment. Fill in your e-mail address for quick registration.
Title: Brain 'not fooled' by sweeteners
Author: Luisetta Mudie
Article Id: 12518
Date Added: 1st Sep 2009