New study highlights once again, if necessary, the benefits of a good night’s sleep suggesting that the immune system works more actively at night than it does during the daytime.

The findings were presented Sunday at the American Society for Cell Biology annual meeting in San Francisco.

For the study, researchers at Stanford University used fruit flies to test their theory but there is strong evidence that the same effect can be seen in humans too.

They infected the flies with two strains of bacteria, with some flies getting the bacterial infection during the day and others during the night. The flies that got sick during the night were more likely to survive the infection compared to those getting sick during the day.

“These results suggest that immunity is stronger at night, consistent with the hypothesis that circadian proteins upregulate restorative functions such as specific immune responses during sleep, when animals are not engaged in metabolically costly activities,” Stanford researcher Mimi Shirasu-Hiza said.

This is not the first time when researchers suggest that sleeping is important for our health. Studies have shown that lack of sleep leads to high blood pressure, stroke, heart disease, kidney disease and other illnesses.

Therefore, people should sleep at least 7 to 9 hours per night in general, although some people function well with less while others need as much as ten. Of course, sleep pattern changes with age. For example, adolescents need at least 9 hours of sleep per night, while newborns and infants need lots of sleep because it is important for their health.