It’s been suggested for a good while by a wide range of studies that inadequate sleep is linked to memory loss. But new research is offering the strongest implication yet that poor sleep leads not only to general memory problems, but even to the specific buildup of toxic proteins that trigger Alzheimer’s disease.
A study published in Nature Neuroscience points to strong evidence that without enough of the deep, restorative (non-REM) sleep that helps the brain preserve memories, beta-amyloid proteins, which build up in “tangles” as Alzheimer’s develops, can take hold in the brain. While killing off brain cells, these protein snarls cause the devastating memory loss characteristic of the disease.
Chicken or egg
Excess deposits of beta-amyloid have been found in Alzheimer’s patients and also, independently, in some people who have sleep disorders. What hasn’t yet been figured out is the chicken or the egg. Does missing out on restorative deep (non-REM) sleep cause the protein to collect in the brain, or does the protein buildup cause the loss of deep sleep?
“It’s a vicious cycle,” reported Matthew Walker, a University of California at Berkeley neuroscience professor and the study’s lead author. “But we don’t yet know which of the two factors—the bad sleep or the bad protein—initially begins this cycle. Which one is the finger that flicks the first domino, triggering the cascade?”
The research team has received a major grant from the National Institutes of Health to conduct a long-term study that will try to clarify the connection.
How about now?
A longitudinal study takes years. But waiting for conclusive medical proof shouldn’t be necessary to improve your chances against Alzheimer’s, given what is already known about sleep and memory problems.
Fortunately, there are many ways to improve your sleep right now, so you can benefit from more of its memory-storing, deepest stages as they occur in cycles throughout the night.
Sleep hygiene is brain hygiene
Adequate sleep helps your brain cleanse itself of toxic byproducts, including protein buildup. And the starting point for adequate sleep is good sleep hygiene. Here’s how to practice it.
- Stick to a schedule. Your body likes routine, so get up and go to bed at the same time daily, even on weekends. When you’re tempted to sleep in, limit extra sleep to one hour.
- Design a bedtime ritual. Wind down with the same steps every night, which helps cue your brain to sleep.
- Use the right light at the right time. Seek out bright light (sunlight’s best) first thing in the morning, and minimize your exposure to blue light (screens, devices, CFL bulbs) at night.
- Maintain an exercise routine. It tires you in a positive way. Any time is fine for working out except shortly before bed, when it’ll make you more wakeful.
- Skip evening stimulants and alcohol. Smoking, caffeine or alcohol in the evenings all undermine your sleep. The first two rev you up, and while a drink may help you drift off, alcohol causes shallower sleep later. (Stop all liquids by 8pm, to avoid waking to use the bathroom.)
- Eat lightly at night. Large or spicy meals can lead to indigestion, which interferes with deep sleep—even when it doesn’t wake you up.
- Maintain bedroom basics. Keep it cool (60-67 degrees), dark, and quiet. Declutter, too. If you can’t sleep, go be awake in another room and return when you’re drowsy again.
- Nix the nap habit. An occasional “power nap” (20 minutes) is fine but regular napping promotes insomnia.
- Create a comfortable bed. Choose a high-quality natural mattress and pillows, with allergy protection if you need it. You’ll sleep best on a customized mattress made just for your body.
Don’t avoid the doctor
If your sleep hygiene is in good shape but you’re still not getting enough regular, deep sleep, see your doctor. An underlying condition might be part of the problem, and the sooner you have your sleep issues evaluated, the sooner you’ll get more of the brain-preserving rest you need.
