A good night’s sleep is not just vital for resting and repairing your body, but is crucial for brain health too. While your body’s lymphatic system carries away cellular toxins while you sleep, helping to ward off disease, it was recently discovered that your brain has its own separate system to do this, called the glymphatic pathway. As toxins are cleared, it frees up your brain to consolidate the day’s memories so you wake up sharper. Sleeping on your left optimises this, due to the flow of cerebral fluid.

What’s more, it’s now been discovered that vital immune cells called microglia are at their most active when you sleep. This leads to better cognition, a reduction in brain disorders such as autism, schizophrenia and dementia, plus an improved ability for your brain to fight off infection and repair damage after trauma from things like a stroke or an accident. Microglia are essentially first responders, patrolling the brain and spinal cord and reacting as soon as they spot infection or debris from dead cell tissue that needs getting rid of.

Another thing your brain needs deep sleep for is hormone regulation. Cortisol, the stress hormone falls when you sleep deeply, while growth hormone increases. If cortisol stays low it keeps insulin low too, which helps with memory formation. And you need growth hormone for brain cell repair and improved attention.

So how do you get that all-important, restorative deep sleep? Routine is key – when you fall asleep is as important as how much you get, so wait until you’re really sleepy and stick to that time every night. Magnesium and omega-3 supplements will help you fall asleep as well as enhance brain repair. It helps to avoid caffeine after 2pm, as well as reducing phone or TV use an hour before bed, as the ‘blue light’ from gadgets keeps your brain awake.