What’s sleep got to do with your memory?

In this blog post, we are sharing key points on the connection between sleep and memory:

Sleeping six hours or less

Sleeping six hours or less puts you at a higher risk for dementia as you age. The likelihood of you being diagnosed with dementia is 30% more than if you sleep seven hours per night.  

Seven to nine hours of sleep

It is important to sleep seven to nine hours each night. Why? When we sleep, we go through the four stages of sleep (light non-REM sleep or falling asleep; light non-REM sleep; deep non-REM sleep; and REM sleep or dream sleep) in approximately 90-minute sleep cycles.  Each has restorative qualities important to the healthy functioning of our mind and body. We need to experience five to six cycles per night to fully benefit from each sleep stage, and 7-9 hours are needed to complete those sleep cycles.  

The hippocampus

The hippocampus is a key part of the brain. It is where new memories are formed, and it is negatively affected by lack of sleep. While we’re awake, we collect memories every moment… but most of those are mostly forgotten rapidly. When we sleep, we strengthen some memories. To quote Dr. Robert Stickgold of Harvard Medical School, “Sleep seems to be a privileged time when the brain goes back through recent memories and decides both what to keep and what not to keep.” (maybe use a photo of the hippocampus for this item)

Sleep patterns

Our sleep patterns change as we age and our memory-strengthening deep sleep stages start to decline as we reach our late 30s. Sleep experts led by Dr. Matthew Walker of UC Berkeley found that adults beyond age 60 lose 70% of deep sleep compared to young adults ages 18 to 25.  Memory impairment among older adults, manifested in difficulty remembering things the following day, is linked to reductions in sleep. Improving deep stages of sleep in older people is an important area of continuing study among sleep researchers. 

Improving sleep duration

For you to improve your sleep duration, here are a few tips:  

  • Doing exercise and intense physical activity during the day can help with sleep, but leave at least an hour between exercise and bedtime to enable your body to lower its temperature and heart rate before sleeping.
  • Take a hot bath or shower 1 to 2 hours before bed to decrease your body temperature. 
  • Put on pink noise (random noise having more low-frequency components than white noise) as background as you doze off and throughout the night.  Pink noise is available for free on many smart speakers and streaming apps & websites.
  • Stay away from caffeine later in the day… try to avoid it within 8 hours of your bedtime.   
  • Choose meals with fewer carbohydrates and more fats.
  • Avoid alcohol within 4 hours of your bedtime.  Alcohol can make you drowsy, but it can also increase your heart rate and interfere with REM sleep.

References:

  1. https://newsinhealth.nih.gov/2021/06/lack-sleep-middle-age-may-increase-dementia-risk
  2. https://recharge.energy/en/sleep-cycles/#The_Science_of_Sleep_-_Understanding_Sleep_Stages_and_Sleep_Cycles 
  3. https://newsinhealth.nih.gov/2013/04/sleep-it#:~:text=Lack%20of%20sleep%20affects%20a,%2C%E2%80%9D%20says%20sleep%20expert%20Dr
  4. https://newsinhealth.nih.gov/2013/04/sleep-it#:~:text=Memories%20seem%20to%20become%20more,may%20help%20with%20problem%2Dsolving
  5. https://recharge.energy/en/deep-sleep/#Tips_and_strategies_to_improve_deep_sleep