Not getting enough sleep might be way worse for you than we thought

Losing one night of sleep may do far more damage to your body than simply making you groggy the next day.

A few years ago, scientists figured out which genes are associated with your biological clock - the thing that wakes you up in the morning and tells you when you need to get some sleep.

These so-called "clock genes" make proteins that rise and fall throughout the day and control various bodily functions, including when we sleep and and when we wake up. Our body clocks also help regulate many other things, from our body temperature to our heart rate, blood pressure, and metabolism.

In a small study published earlier this month, researchers at Uppsala University in Sweden found out that our "clock genes," like many of our other genes, may be negatively affected by external factors in our environment, a field of research known as epigenetics. And these changes, they hypothesized, could take place over the course of just a single night of missed sleep.

While epigenetics itself is still a pretty new field, scientists are discovering that the genes that are altered in this way - known collectively as our epigenome - are affected by everything from what we eat to how stressed we are.

It's important to keep in mind that the effects the researchers observed didn't involve changes to the genes themselves, but rather in how they were expressed. Researchers liken these effects to switching genes on our off. And not sleeping - even for just a single night - appeared to switch some genes off.

To get their results, the researchers had 15 healthy men in their early 20s spend two nights in a lab. On one of the nights they got to sleep a full eight hours, but on the other night they had to stay awake, which the researchers ensured by keeping a close eye on them and not letting them get into bed.

On both mornings, the researchers collected samples of connective tissue below the skin and skeletal muscle to get a look at their genes.

In just one night of not sleeping, some genes appeared to have been hypermethylated, or essentially switched off. That could be bad news for the metabolism, since some of the genes that are affected by lack of sleep are also the genes that break down the sugar from the food we eat. If these blood-sugar-processing-genes are silenced, they can't to do their job.

Christopher Payne, a professor of human molecular genetics at Northwestern's Feinberg School of Medicine who was not involved in the study, expressed some concerns over the limitations of the study: particularly the small sample size, the fact that they only looked at two samples of tissues and only studied four genes. But, there's one positive thing the study did find, Payne said:

"The study does provide evidence that there are measurable changes to the circadian clock from just one lost night of sleep."

The researchers haven't figured out if these changes are permanent yet. Payne said from what we know about epigenetics, the changes are likely reversible, so long as they're not consistently repeated.