If you make a habit of staying up when you should be sleeping, do your brain a favor and avoid raiding the refrigerator.
That’s what University of California, Los Angeles (UCLA) researchers advise after they studied the effects of odd-hours feedings on laboratory mice. Snacking during sleep time, they found, disrupted the part of the brain that controls learning and memory. The findings were published in the journal eLife.
Building on earlier research showing that shift workers underperform on cognitive tests when compared with their 9-to-5 counterparts, the UCLA team sought to learn what exactly was happening in the brain during those late-night snacking sessions.
“We have provided the first evidence that taking regular meals at the wrong time of day has far-reaching effects for learning and memory,” lead author Dawn Loh said in a statement released by the university. “Since many people find themselves working or playing during times when they’d normally be asleep, it is important to know that this could dull some of the functions of the brain.”
Loh and her team found that the mice that were regularly fed during their normal sleep time were less able to identify new objects introduced into their environment than those who ate at their proper feeding time. Long-term memory was similarly affected.
The off-kilter feeding schedule apparently reduced the activity of a key protein called CREB in the hippocampus, the part of the brain that stores and organizes new memories. At the same time, the part of the brain that controls our circadian system — the suprachiasmatic nucleus in the hypothalamus — is not affected by the feeding change, which creates a misalignment between the two brain regions, leading to the memory problems.
“For the first time, we have shown that simply adjusting the time when food is made available alters the molecular clock in the hippocampus and can alter the cognitive performance of mice,” said Christopher Colwell, a professor in UCLA’s Department of Psychiatry and Biobehavioral Sciences. “Modern schedules can lead us to eat around the clock, so it is important to understand how the timing of food can impact cogitation.”
Late-night snacking can also disrupt sleep patterns, which can lead to a host of health issues. So stay on a healthy sleep schedule with these tips from “Sleep Deficit” in our May 2015 issue.