Personal Injury Law

Immunity Stronger At Night During Restorative Sleep

By Jane Akre

A good night's sleep helps the body fight invading bacteria - at least Stanford researchers found that to be the case in fruit flies.

Both humans and the fruit fly operate on circadian rhythm which paces the living bodies through day and night, setting the rest/activity cycles that cues us when to eat, sleep and mate over a 24-hour cycle.

A good night's sleep might mean that the body has the ability to fight invading bacteria at night while the body is restoring the immune response.

"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," said Stanford researcher Mimi Shirasu-Hiza in a statement. 

The research was to be reported Sunday at the American Society for Cell Biology annual meeting in San Francisco.

In phagocytosis, the innate immune response targeted by the Stanford researchers, specific immune cells engulf and destroy the bacteria invading the body.

In this experiment, the flies were infected with two different types of bacteria. Those infected at night were more likely to survive than those who were infected during the day. Flies that had a low immune response also have a corrupt circadian clock.

In previous experiments, the researchers saw that flies that will sick with bacterial infections lost their circadian rhythm. Flies that lacked a circadian rhythm were highly susceptible to infection.

Not having your internal clock working properly may disable your immune response making you more susceptible to bacterial infection. There are also implications that may apply to a number of human diseases such as cancer and neurodegenerative disorders. 

Researchers have identified several genes that may regulate human circadian rhythms.

According to studies, there may be a genetic reason why some people are night owls and others are early birds. Stanford University research and the University of Wisconsin have identified a gene mutation that seems to account for a person's preferred time of day. 

Genetics may also determine why some people suffer from insomnia. Mild brain injuries may disturb circadian rhythms. #

Full post as published by InjuryBoard on December 15, 2008 (boomark / email).