Our brains consume over 20% of all metabolic activity (mainly oxygen & glucose) in the human body, even though the average brain comprises only 2% of body weight. This outsize power usage produces a host of byproducts, including amyloid beta protein, one of the hallmarks of Alzheimer’s disease.
The first study, published in the journal Science, looked at how the brain clears metabolic debris from a busy day. During sleep, researchers found that the interstitial volume (the fluid filled space between brain cells) increased by 60%, which allowed the brain to clear amyloid beta and other waste products at a much faster rate than during waking hours.
In other words, the brain’s garbage disposal system kicks into high gear when we are sleeping, clearing toxic amyloid beta, and getting us ready for the new day.
This leads us to the second study published in JAMA Neurology, which found a strong correlation between poor quality sleep (both short & disturbed sleep patterns) and a chronic buildup of amyloid beta protein in the brain. It’s unclear whether poor sleep triggers the amyloid accumulation in the brain, or if the amyloid beta buildup prevents quality sleep – it’s probably a cascade process that triggers a harmful feedback loop.
Bottom line: get a solid 8 hours of sleep each night for good brain health. Keep in mind these sleep hygiene tips:
- Associate your bed and bedroom with sleep. It’s not a good idea to use your bed to watch TV, listen to the radio, or read.
- Avoid stimulants such as caffeine, nicotine, and alcohol too close to bedtime. (Alcohol metabolizes into glucose, which is a stimulant to the body.)
- Ensure adequate exposure to natural light during waking hours – use a lamp that simulates sunlight if necessary.
- Daytime exercise can promote good sleep. A relaxing exercise, like yoga or meditation, can also be done before bed to help initiate a restful night’s sleep.
See also: Linking Exercise to a Healthy Brain