Australian researchers have discovered that sweeteners have side-effects which are worse than the benefit. Studies have suggested that consuming artificial sweeteners actually make you feel hungry and prompt you to eat more unknowingly, said a new study by the University of Sydney scientists.
Researchers from the University of Sydney’s Charles Perkins Centre and the Garvan Institute of Medical Research have identified a new system in the brain that senses and integrates the sweetness and energy content of food.
"After chronic exposure to a diet that contained the artificial sweetener sucralose, we saw that animals began eating a lot more," said lead researcher Associate Professor Greg Neely from the University of Sydney’s Faculty of Science.
"Through systematic investigation of this effect, we found that inside the brain’s reward centres, sweet sensation is integrated with energy content. When sweetness versus energy is out of balance for a period of time, the brain recalibrates and increases total calories consumed."
In the study, fruit flies that were exposed to a diet laced with artificial sweetener for prolonged periods (more than five days) were found to consume 30 percent more calories when they were then given naturally sweetened food.
"When we investigated why animals were eating more even though they had enough calories, we found that chronic consumption of this artificial sweetener actually increases the sweet intensity of real nutritive sugar, and this then increases the animal’s overall motivation to eat more food," said Associate Professor Neely.
Billions of people worldwide consume artificial sweeteners as a remedy to obesity but in turn it is leading to obesity, said researchers, chaning the previously held view about the entire gamut of sweeteners, which have a global market of millions of dollars.
This is the first study to identify how artificial sweeteners can stimulate appetite due to a complex neuronal network that responds to artificially sweetened food by telling the animals or humans that it hasn’t eaten enough energy.
"Using this response to artificially sweetened diets, we were able to functionally map a new neuronal network that balances food’s palatability with energy content. The pathway we discovered is part of a conserved starvation response that actually makes nutritious food taste better when you are starving," said Associate Professor Neely.
The researchers also have other side-effects, said researchers who found them causing hyperactivity, insomnia and sleeplessness, causing mild starvation among others. When Professor Herbert Herzog’s lab from Garvan replicated the study using mice, they began to consume food in higher volumes.
"These findings further reinforce the idea that ‘sugar-free’ varieties of processed food and drink may not be as inert as we anticipated. Artificial sweeteners can actually change how animals perceive the sweetness of their food, with a discrepancy between sweetness and energy levels prompting an increase in caloric consumption," Professor Herzog said.
The findings are published in the journal Cell Metabolism.