With the holidays almost upon us, there's likely to be jet lag or other sleep pattern disturbances in your near future. But new research shows that jet lag health effects are more serious than we may have realized — sleep disruptions like jet lag contribute to Alzheimer's symptoms like memory and learning loss, so you might want to do whatever you can to stay on track. It's no secret that regular, good-quality sleep is critical for your health, but the health consequences of missing out on it are even more serious than you might have thought.
Research led by the University of California at Irvine's biomedical engineering professor Gregory Brewer hoped to shed light on the direction of causality between sleep disturbances and Alzheimer's symptoms. In other words, do people develop messed-up sleep habits because they're already coming down with Alzheimer's? Or do abnormal sleep habits (developed for whatever other reason) contribute to the onset of Alzheimer's and its symptoms? It could be a little bit of both, but figuring this out matters because it helps us to know more about who's at risk for Alzheimer's, and which health interventions are likely to strike at the root of this disease.
Brewer and his team separated mice into two groups, and inflicted one group with circadian rhythm disturbances by intermittently shortening the dark period in their environment. Essentially, the treatment mice became super jet lagged, whereas the control mice slept normally. The jet lagged mice showed a large drop in a critical, protective antioxidant in their brains, and became much worse at a water maze test of memory. The antioxidant, glutathione, is believed to play an important role in brain metabolism and inflammation, so a long-term deficiency would be very likely to alter the physical properties of the brain for the worse.
Does any of this mean that you should skip that long-awaited trip to Europe? Definitely not — a short-term lack of sleep might make you temporarily worse at daily activities, but it's not going to give you Alzheimer's overnight. Nonetheless, you should be careful not to let a chaotic period turn into a long sleep-disturbed stretch, or even your new normal. Many of the avoidable health problems we develop are the result of chronic suboptimal conditions (junk food, smoking, drinking), and days turn into weeks turn into years before you know it. And probably none of the things you're staying up late for are worth years of cognitive disability in the future.