We have just kicked off the holiday season enjoying a Thanksgiving feast with our family and friends. After bantering and overindulging on turkey and sides, drowsiness gets the better of many of us and we can think of nothing more than sitting back and falling into a nice post-meal snooze – a “food coma”. While we’ve managed to avoid the post-feast cleaning, much to others annoyance, we may actually have some evidence rendering our slothful behavior a physical condition.
Although many have speculated the link between food and sleepiness there is little scientific evidence to back it up. However, a recent study conducted by a team of researchers at The Scripps Research Institute, are unraveling this mystery. Using a common fruit fly model, Associate Professor William Ja and his team, showed that food consumption had a positive effect on post-meal sleepiness, and the larger the meal consumed, the longer the fly slept – flies generally slept for 20 to 40 minutes with the longest time seen in flies consuming more food. However, not all food is equal – foods that were protein-rich and salty promoted sleep while sugary foods did not.
By switching neurons on and off in the flies brain, Ja and his team were able to take their investigation a step further and reveal a number of the circuits responsible in controlling this post-meal sleepiness, and thus highlight a number of different ways the post-meal sleepiness can be regulated – including the flies’ own circadian rhythm and the influence of protein on the leucokinin system. More research still needs to be conducted to reveal the extent to which these circuits have an effect on post-meal sleepiness and why this behavior is seen in animals. “This behavior seems conserved across species, so it must be valuable to animals for some reason” said Ja.