Dementia

Tips for a good night’s sleep to head off dementia.

Our brains are very active when we are asleep and there is mounting evidence that deep sleep plays a vital role in memory and may even protect us against Alzheimer’s.

Deep sleep is one of the four main stages of our sleep cycle.   It’s also known as slow-wave sleep because it’s when millions of neurons in your brain start firing together, producing big waves that slowly travel through your brain.   In deep sleep you’re at your most relaxed, and difficult to rouse, but below the surface there is plenty going on.   Your pituitary gland in the brain starts to secrete more growth hormone, vital for cell growth and repair, for instance.

Deep sleep also boosts production of cytokines, a type of protein that’s key for helping fight infections, which is partly why a lack of deep sleep makes you more vulnerable to colds and reduces the efficacy of vaccines against infections such as the flu.     Deep sleep is when a network of channels in your brain known as the glymphatic system, opens, allowing fluid to pour though it, washing away the toxin waste that’s built up during the day.   Which in turn can protect us from the impact of diseases such as Alzheimer’s.   This was demonstrated in a new study by the University of California (UC), Berkeley.   The results showed that despite having high amounts of amyloid in their brain, the participants who got plenty of deep sleep did far better in memory tests than those who had less.   Researchers think deep sleep could help explain why some people, despite their brains being clogged with amyloid, continue to thrive into old age, while others develop signs of dementia.

Matthew Walker, a professor of neuroscience at UC Berkeley and a leading sleep expert explained:  “Think of deep sleep almost like a life raft that keeps your memory afloat, rather than memory getting dragged down by the weight of Alzheimer’s disease.

Adults typically get around one to two hours of deep sleep a night, but this tends to drop off as we get older.   So how can we boost it? Apart from obvious things, such as cutting back on booze and getting to bed reasonably early, cutting down on junk food and eating a higher fibre Mediterranean-style diet.    Numerous studies have shown that people who follow a Mediterranean-style diet (one that is rich in nuts, olive oil, oily fish and vegetables) have better quality sleep, while those who each junk food tend to struggle.