Dr. Giulia Enders

What happens if we're not getting enough sleep?

Well, quite a lot of things.

One thing, as we were just talking about, is that sleep is the time when most of the immune cells are being produced.

And this is because during sleep, we're not being disturbed by all these foods or having to run or metabolic challenges, stress, signals from the brain disturbing everything.

No, we're in complete harmony with just regulating our insides perfectly well.

And during that time, cells make remarkably less mistakes.

So it's smart of them to pack all their processes and dividing and producing new cells, put a big chunk of that right there in the middle of sleep so that they're not being disturbed and need less energy to fix mistakes later on.

So this is one thing that's happening there and also a thing why, for example, shift work can then be a bit risky for your risk of developing cancer, for example.

Because if you disturb this process all the time and cells don't have this calm space to divide with less mistakes, well, then they can make more mistakes.

It just adds up over many years of working, not within a week or a stressful year even.

We get this vast amount of data from everybody who are Zoe members.

Almost everybody reports the fact that their sleep is not as good as it should be.

I think we all know the things in modern life like phones and TVs and electric lights that I think mean we tend to sleep less than our ancestors would.

Does that mean that if they were able to sleep better, that that would probably help

improve sort of the balance of their immune system?

I mean, it depends on how severe your sleep disruption is.

The immune system needs especially the first half of the night because that is when there's most deep sleep.

And deep sleep is the part of the sleep where the cells have this perfect window to multiply.

And then the second half of sleep is more REM sleep, processing feelings, finding new emotions.

These kind of things happen more there.