Could sleep and fasting be the missing pieces of the puzzle?

If you were thinking… well what’s the link between sleep, fasting and my immunity? think again! It’s now well established that eating a healthy and balanced diet, exercising regularly and reducing your stress levels can help the immune system. While an important element in looking after your immune function, sleep is often overlooked. Fasting can be extremely beneficial too, but this one is a little bit more complicated, so I will come to it a bit later.

How does sleep affect my immune system?

A lot happens when you sleep. As well as emotional wellbeing regulation, weight maintenance and protecting from certain conditions like heart disease and depression, sleep has a role in strengthening the immune system.

Just after one night of getting only four or five hours sleep, your natural killer cells drop by as much as 70%!

Your body works hard whilst you sleep, producing a number of proteins and immunity cells to fight off infections and inflammation. A German team found that a good night sleep can boost the effectiveness of certain specialised immune cells called T cells. T cells are a type of white blood cells which are essential to the functioning of the immune system. So, skimping on sleep can make you more prone to falling ill after being exposed to a virus.

Even a modest sleep disruption for a single night can adversely affect the immune system. Just after one night of getting only four or five hours sleep, your natural killer cells drop by as much as 70%! Natural killer cells can kill cancer cells or cells infected with a virus, so they are an important weapon in the armoury of your immunity. In fact, they are part of the first response of our immune system to external attacks. Think of them as sentinels.

Burning the candle at both ends can have a detrimental effect on your health in the long run too. Sleep loss has been linked to long-term health problems like Alzheimer’s disease, cancers, diabetes, obesity and poor mental health.

If you’re well rested, you’ve got a better chance of responding to vaccines. In a joint US and French study, people who were sleep deprived at the time of having a flu jab, had a lower immune response to the vaccine. After 10 days from the vaccination, they only had half the amount of antibodies compared to people who kept to normal sleeping times.

So how can I get a good night’s sleep?

Most of us need seven to nine hours of shut-eye every night. Check out these tips to help you get the amount of sleep you need:

Stick to regular sleeping hours. This means going to bed and waking up at roughly the same time every single day (yes this means the weekends too!). This helps your brain and internal body clock to get used to a set routine. 

Try to wind down before you sleep. Switch to sleep mode by doing something relaxing to prepare for bed. Have a warm bath, read a book, or listen to some soothing music.

Practice mindfulness meditation. Doing some breathing exercises before going to bed can help you relax and unwind. If you can afford it – it costs around £300 – the upgraded Muse S meditation headband may be just the thing to try! It’s built with sleep in mind and helps you drift off by adapting the Go-to-Sleep Journey you hear to your biometrics – like your brain activity and heart rate the band picks up. Clever stuff!

Optimise your bedroom for sleeping. Think dark, quiet, tidy and cool – a temperature between 18 and 24 C is ideal. Don’t forget about your mattress. It should be a comfortable one, not too hard and not too soft.

Dim the lights. Opt for red lights in the evening, as these don’t interfere with the production of melatonin – a natural hormone which controls your daily sleep-wake cycles. Avoid using smartphone and tablets at least an hour before you sleep, as the blue light they give off can interfere with sleep.

How about fasting, can it help my immunity?

Fasting has been linked to several health benefits, including improved blood sugar control, heart health and brain function. Fasting can take many shapes and forms and it’s probably one of the least talked about strategies when it comes to giving the immune system a helping hand.

Fasting reduced the number of white cells, which in turn triggered the immune system to start producing new white cells

In 2016 a Japanese scientist Yoshinori Ohsumi won a Nobel prize for his work on autophagy. Autophagy literally means self-eating. Cells destroying themselves may not sound like a good thing, but autophagy is a natural process by which cells regenerate themselves. Ohsumi found that fasting activates autophagy which has a positive effect on cell renewal and slowing down the aging process. When cells starve, they break down components from faulty cells and recycle them, so they’re used as energy and for cell repair. During autophagy, cells also destroy viruses and get rid of damaged proteins. 

Even though we know that fasting is beneficial, we don’t exactly know how long we should be fasting to reap the benefits. One of the most known fasting strategies is intermittent fasting, in particular the 5:2 diet plan, where you eat normally for five days and fast for two days, limiting your calorie intake on the days you fast. A study done on mice in 2014 showed that fasting for at least two days a week regenerates the immune system. Fasting reduced the number of white cells, which in turn triggered the immune system to start producing new white cells.

During a fast, your immune system could temporarily become weaker, but it bounces back with newer better cells after you start eating – provided you’re eating healthy.

Fasting is not for everyone. It may not be suitable if you have a long-term health condition like diabetes or a heart condition, are pregnant or have an eating disorder. If you’re thinking about giving fasting a go, chat to your doctor first. 

Want to learn more?

If you’d like to learn more about sleep, I recommend ‘Why We Sleep’ by Dr Matthew Walker. The book is beautifully written, packed with scientific evidence and real eye opener (so to speak!).

For more on fasting, have a look at ‘The Complete Guide to Fasting’ by Dr Jason Fung and Jimmy Moore. The book has a wealth of information about different types of fasting and their benefits, all backed by scientific evidence.

And there you have it! So, sleep well, eat less and stay healthy!