A week of bad sleep could "switch off" hundreds of genes and raise the risk of a host of illnesses including obesity and heart disease, scientists have claimed.
According to the new study, getting fewer than six hours' sleep per night deactivates genes which play a key role in the body's constant process of self-repair and replenishment, the Telegraph reported.
Our bodies depend on genes to produce a constant supply of proteins which are used to replace or repair damaged tissue, but after a week of sleep deprivation some of these stopped working.
The findings suggest that chronic lack of sleep could prevent the body from fully replenishing itself and raise the risk of a host of diseases, the researchers said.
Scientists from Surrey University divided 26 volunteers into two groups, one of which slept for less than six hours per night for an entire week, and one which slept for ten hours per night.
At the end of the week each group was kept awake for 40 hours and donated blood samples, which were studied to examine the effects of their sleep regimes.
The week of sleep deprivation was found to have altered the function of 711 genes, including some involved in metabolism, inflammation, immunity and stress.
Inadequate sleep also interfered with genes which are designed to become more or less active at certain points in the day, by throwing off the body's 24-hour internal clock.
Although a week's normal sleep was enough to restore the affected genes to their normal pattern, researchers said that prolonged periods of sleeplessness could lead to serious health problems including obesity and heart disease.
Studies have also shown a lack of sleep can lead to cognitive impairment, for example limiting our ability to drive a car safely.
Prof Colin Smith, one of the authors of the new paper, said: "This is only a week of sleep restriction and it is only five and a half or six hours a night. Many people have that amount of sleep for weeks, months and maybe even years so we have no idea how much worse it might be."
The study is published in the Proceedings of the National Academy of Sciences journal. (ANI)