Why a Lack Of Sleep Makes You Hungry — And Other Sleep Questions, Answered

person sleeping

A Mayo Clinic expert shares important insights and sleep tips

May is Better Sleep Month — and this year, it happens to coincide with a time marked by stress, uncertainty, and health worries stemming from the Covid-19 pandemic. We all know, at a base level, that sleep is important… but why exactly is it so vital for our health and performance? And how can we actually get “better” sleep, especially during a time like this?

To help us find out, we turned to Virend Somers, MD, PhD, the Alice Sheets Marriott Professor of Medicine and a physician in Cardiovascular Medicine at Mayo Clinic, as well as a member of Sleep Number’s advisory board. He offered up some important insight and tips.

Wake-Up Call: Why, through all this uncertainty, is sleep more important than ever?

Dr. Virend Somers: This is obviously a different time — and then we have to think about what people are doing right now. Generally, they’re more anxious than ever, for understandable reasons. The anxiety and the stress is often raising their blood pressures. Depression and suicide is worrisomely high, and likely to increase as the fallouts and lockdowns continue. But there are some natural cures here from sleep — because sleep helps mitigate all of these.

Sleep lowers your blood pressure, and it makes us less likely to be depressed. So we have to think of sleep as nature’s medicine. Then the other aspect, paradoxically, about this very strange time is that people should see this as an opportunity to get more sleep — because more sleep is feasible. People are working from home home. They don’t have to commute. They have more time in which they can sleep. So this is a time to improve sleep habits.

Can you elaborate on how exactly sleep could help us manage our anxiety during this time?

Anxiety and sleep is a vicious cycle. The less sleep you have, the more anxiety you have during the course of the day — and then the more anxious you get, the less sleep you get because then you start ruminating on all kinds of real and imagined issues, problems and occurrences. We could break the cycle by taking medication that blunts our anxiety, or alternatively, we could try to get more, healthier and restful sleep.

The other thing that they want to be careful about: Where is this anxiety coming from? It’s often coming from the news. So you don’t want to have a TV or a radio in your bedroom — or be listening to that just before you go to sleep. You want a gap period, or a cooling down period, between watching the news and trying to get to bed. That’s one way of decreasing the anxiety around sleep.

When we think about REM sleep — that’s when we dream. During REM sleep, what seems to be happening is that channels open up in the brain that wash away the cellular waste products. Think about how in New York at night, you’ve got all these trucks coming around and washing the streets and the sidewalks and getting rid of the trash. That’s kind of what’s happening to us at night when we sleep — the brain’s cleaning itself. So you have to think about dreams as a way that the mind cleans house. This is why sleep is so important: If you can clean away all that anxiety that’s bouncing around in your mind, you will be less anxious through the baseline. And that’ll give you an opportunity to sleep better at night.

That makes sense. Now, as an expert, can you tell us, briefly, about the link between sleep and cardiovascular health?

In a nutshell, better sleep is linked to lower blood pressures and lower long-term cardiovascular risk. There’s all of this evidence that longer sleep, better sleep, and higher quality sleep is accompanied by improvements in very concrete measures of cardiovascular health and cardiovascular disease.

Can you explain why sleep is important in weight management?

The short answer is we don’t know for sure, but we can make some guesses. We think, perhaps, that sleep affects the production of certain hormones. One is leptin and the other is ghrelin. Leptin is produced by the fat cells and it kind of talks to the brain — telling the brain, “Okay, you can stop eating now.” Ghrelin, on the other hand, makes you hungry.

So there is some evidence that people who sleep less produce more ghrelin and less leptin — and if you sleep more, you produce more leptin and less ghrelin. We don’t know for sure. All we do know, at least from the data from our lab (as well as other people’s work), is that if you compare people who are randomized to sleeping less, to those who are randomized to sleeping more, the ones who are randomized to sleeping less eat several hundred calories more per day than the ones who have longer sleep.

In what other ways does quality sleep help keep us healthy — particularly in regards to our immune system?

The field of immunology is very complex, and the field of sleep is also very complex. It’s just been the last decade or so that we’ve begun to understand how closely the two are linked. Here, an example of how important sleep is: If you sleep more, you tend to have a more robust response to vaccination. So with the flu vaccine, there’s something about getting longer sleep that allows the body to mount a greater immune response. The details of that we’re still working out, but that is what we know — your immune response is improved by sleeping more.

Great. So, our last question: What tips do you have for ensuring we all get quality sleep right now?

Before we sleep, what can we do to ensure that the sleep period is going to be as high quality as possible? The first is let’s avoid taking naps. If you take a nap during the daytime, particularly if you’re older, you are less likely to sleep well during the night — because you’ve already had some sleep. The second is phones. We have to avoid all of the artificial light sources that we’re exposed to, especially in the last two to three hours before bed, because the light from the phones and screens shuts down our melatonin — and melatonin makes us sleep. So the less blue light we’re getting, the better.

Then the obvious thing is to avoid wine, avoid coffee, and avoid eating within a couple hours of going to bed. So that’s all the prep that you need before sleep. Now what happens when you’re sleeping? You need to be sure that you have a very quiet bedroom, with no ticking clocks. You need to be sure that there’s no lights in the bedroom. One quote that I always think of: “Sleep is the rock upon which you build your day.” That’s the way that I like to talk to patients about sleep.

This interview has been edited and condensed.

This originally appeared on Medium.