Sugar Leads to More Sugar
The taste of sugar is one of the most basic sensory experiences for humans and other animals. The sweet taste is one of the first sensory pleasures we experience. Our mother’s milk and formula milk taste sweet due to the milk sugar lactose.
Eating sugar activates the brain’s reward system, making us feel good. This was useful when sugar was a good source of calories needed for survival. Sweet foods are generally safe to eat and sweetness indicates calories meaning our ancestors were driven to seek them out. However, in a world where sugar is abundant, this deeply ingrained appetite for the sweet stuff is the cause of many problems. Studies have linked excess sugar consumption to obesity, type 2 diabetes and metabolic syndrome.
Sugar and the Brain
Scientists have known for a while that sugar exerts a special control over the brain. Even mice without the ability to taste sweetness choose sugar. It turns out that not only do sugar and sweet tasting foods trigger taste buds on the tongue they also switch on a neurological pathway that begins in the gut and goes up to the brain. When sugar is eaten sensors in the gut spark a signal that travels via the vagus nerve to the brain. These signals that herald the arrival of sugar nurture an appetite for more sugar.
Previously, scientists speculated that sugar’s energy content, or calories, explained its appeal, since many artificial sweeteners lack calories. However, this study shows this is not the case, since calorie-free, glucose-like molecules also activate the gut-to-brain sugar-sensing pathway.
Discovering this circuit helps to explain how sugar directly impacts our brain to drive consumption. It is hoped that these findings will drive the discovery of new strategies to curtail our appetite for sugar (1).
If you want to find out about an alternative to sugar that has fewer calories and many health benefits read the blog post Sugar – What’s the Alternative? You’ll also find a recipe for a delicious gluten free, vegan Orange and Almond Cake. For info about how sugar may lead to increased fat synthesis in the liver read Sugar and Fat Synthesis.
1. Apr 2020, 580, 511–516. The Gut-Brain Axis Mediates Sugar Preference. Hwei-Ee Tan et al.