How are you sleeping in these days of Covid? A straw poll on a recent Zoom call with friends revealed everything from ‘sleeping like a baby’ to ‘I’m up at 3am every night sanitising door handles’. Much to my surprise, I’m sleeping better than I’ve done for years, with less traffic noise and work-related stress to keep me awake.
Quality sleep is vital both to the ageing body and to our immune systems. Don’t ever think that our bodies ‘shut down’ when we go to sleep. The reality is that they’re as busy as ever, healing and repairing while we’re in the land of nod, we’re just not aware of it.
SLEEP AND VIRUSES
Research published last year revealed that a good night’s sleep can boost the effectiveness of specialised immune cells called T cells. These cells go into battle to protect us when a potentially harmful foreign body, like a virus, enters our system. When the going gets tough, T cells call in reinforcements – a sort of Panzer division of immune cells – known as integrins, to help out. Integrins help T cells attach to and tackle their targets. Scientists found that participants in the study who had slept well had higher levels of integrin activation that those who’d stayed awake.
SPRING CLEANING OUR BRAINS WHEN WE SLEEP
When we’re asleep our immune systems can also get to work ‘spring cleaning’ our brains. In deep, or slow-wave, sleep the glymphatic system clears out toxins which accumulate during the day. Recent research shows that microglia – immune cells which act as brooms to sweep accumulated toxins out of the brain – work much more effectively while we sleep. This makes the sleeping brain better at removing the beta amyloid implicated in Alzheimer’s. As we enter deep sleep, the brain physically alters, with cells shrinking up to 60% to allow cleaning between them – the neurological equivalent of shifting the furniture around when you give the house a spring clean! Isn’t that extraordinary? I find it mind-blowing.
With that deep cleaning process in mind, it’s unsurprising that poor sleep quality has been linked to a build-up of amyloid beta plaques. Research on people in their 70s found that those who reported sleeping less had increased build-up of beta amyloid. And when participants in one study were allowed to sleep, but disturbed enough to prevent them entering deep sleep, there was more amyloid in their systems after just one night. To make things worse, amyloid plaques build up in the area of the brain that triggers deep sleep, creating a cascade effect: the poorer our sleep quality, the harder it is for the body to flush out amyloid, the more amyloid in the brain, the less able we are to sleep.
HOW ARE YOU SLEEPING?
The lighter evenings mean that we’ve a longer window in which to get our allotted daily exercise. Do read Annabel’s blog about how evening exercise can increase deep sleep to help give your brain a spring clean, and boost your T-cells. If you’re struggling to sleep, I wrote a post on what worked – and what didn’t – when I decided to spend a lot of money on improving my sleep quality. (Clue: the best things in life are often free) I’ve listed a few other posts on sleep, and immunity, below and let us know how you’re sleeping in the comments.
Photo: Dominic Morel