The war between sugar and artificial sweeteners rages on, and the last battle didn't go well for artificial sweeteners. A recent study by a team of researchers at The Yale University School of Medicine and published in The Journal of Physiology has found that when given the choice of either real sugar or an artificial sweetener, laboratory mice responded more favorably to the “real thing”. The study raises an important question about whether artificial sweeteners will keep our appetites satisfied – or if they are likely to create more cravings down the road.
An artificial sweetener - like sucralose, saccharin, and aspartame - is a food additive substituted in place of sugar that replicates the effect of sugar in taste, usually with less food energy (ie, calories). All artificial sweeteners are synthetic. Non synthetic (or natural) replacements for sugar - like agave, xylitol, and sorbitol - are called sugar substitutes.The researchers, led by Professor Ivan de Araujo, put hungry mice through a number of tests involving artificial sweeteners vs. real sugars (glucose) and then monitored their responses and the dopamine levels in their brains. Dopamine, (the “reward signal” in our brain) is a chemical messenger that affects behavior, emotional responses and our ability to feel pleasure. Even with artificial sweeteners many times sweeter than sugar, the mice consistently preferred the real thing, suggesting that sweetness alone was not enough to determine their preference. Could it be that their brains knew that the sweet substitutes were not going to provide the necessary calories their cells craved?That is exactly what the mice's behavior suggests to Dr. Araujo and his team. Their brains chose real food rather than being tricked by “energy-less” artificial ingredients devoid of calories. When real sugar is broken down and used as fuel, our reward signals are happy and we feel satisfied. De Araujo refers to this as the “sugar-to-energy pathway”. With artificial sweeteners offering low or no calories and thus no energy component, the brain is not getting the message that it is full, and there is then no experience of satiation. With no satiation, the brain craves more. This is when the sweet tooth becomes, according to Dr. David Katz, Founding Director of the Yale Prevention Research Center, the ravenous sweet fang.Although these studies were conducted on laboratory mice, the researchers feel confident that the findings can be applied to humans as well.Nature World News recently reported that nearly 30% of the people in the United States currently consume low calorie food or drinks with artificial sweeteners, yet obesity is continually on the rise. This study helps make sense of this apparent incongruity. De Aroujo and his team suggest that we may be more likely to “relapse and choose high calorie options with real sugar to make us feel more satisfied in the future”. While we might enjoy the flavor of a substitute, without the overall feeling of being satisfied we might then look for other options – possibly with high calories to make up for the loss. “We believe that this discovery is important because it shows how physiological states may impact our choices between sugars and sweeteners.”While this research does not suggest that we add more sugar in our diets, it does make us look at our overall food consumption, our choices, and how our bodies respond to them. By only consuminglow calorie options, we may believe that we are living a healthier lifestyle. This study suggests there are other factors to consider when deciding what is best for our overall health.