Souring on Sweeteners: Why Diet Sugars Don’t Work
Sweet Serendipity: It was 1878, when a beaker of coal tar compounds boiled over in the chemistry laboratory of Ira Remsen at the newly founded Johns Hopkins University. Researcher Constantine Fahlberg cleaned up the mess, but later at dinner, his hands tasted surprisingly sweet as he put a piece of bread in his mouth. And this is how the first artificial sweetener was discovered! Named saccharin, it was 300 times sweeter than sugar. Soon, it was being prescribed to President Theodore Roosevelt, to counter his corpulence. More low-calorie sweeteners followed: sucralose, stevia and neotame, the last one being 10,000 times sweeter than table sugar. Today, 30% of adults and 15% of children in the U.S. consume low calorie sweeteners. A sweet deal, right?
Caloric Contradictions: Unfortunately, counterintuitive to expectations, studies show that people who consume large amounts of artificially sweetened drinks gain more weight and body fat compared to those who don’t. Could this be a case of reverse causation? Perhaps, increased body weight encourages people to turn to non-caloric sweeteners. However, this has been ruled out by (i) controlling for baseline body weight at the start of the study and by (ii) looking at weight changes in people who are not overweight to begin with. Another possibility is cognitive distortion: because non-caloric sweeteners are perceived to be healthy, we take that as permission to consume more high-calorie foods. Imaging studies of the human brain reveal a metabolic cause: unlike ordinary sugar, non-caloric sweeteners do not trigger the reward circuits that initiate satiety and fail to activate normal pathways of insulin release needed to deal with caloric loads.
Diet to Diabetes: New research in both mice and humans showed that artificial sweeteners also change our gut microbiome, leading to glucose intolerance, the first step to diabetes. Surprisingly, if the feces from saccharin-fed mice was transplanted into mice whose guts were first cleared of bacteria by antibiotics, the sugar handling defect could be induced in the healthy mice. Oh,
The Archies sang, ♫ Oh honey, sugar, sugar..you are my candy girl and you’ve got me wanting you ♫
REF: Artificial sweeteners produce the counterintuitive effect of inducing metabolic derangements. Susanne Swithers (2013) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3772345/
News Story & Link to Nature paper: http://www.nature.com/news/sugar-substitutes-linked-to-obesity-1.15938