Published August 29, 2013
Jet lag can put a major damper on big vacations – but there may soon be a way to avoid it.
A new study published in the journal Cell has uncovered the gene responsible for jet lag, potentially paving the way for drugs that might allow the body to adjust more quickly to a time zone change.
A person’s internal clock can only adjust by one hour every day, according to study author Dr. Stuart Peirson. Therefore, when a person lands in a place with a six-hour time difference, it could take up to six days before feelings of tiredness, wooziness and grumpiness subside.
However, researchers have long been baffled by the body’s inability to adjust more quickly.
“The basic premise is (that) the biological clock is based on these clock genes that occur inside all cells,” Peirson, a senior research scientist at the University of Oxford, told FoxNews.com. “…Several of these clock genes are regulated in response to light, and that’s what sets (them to the) right time.”
Theoretically, the body should be able to adjust more easily to time zone changes, as the clock genes sense changes in light exposure and respond accordingly.
Seeking a solution to this traveler’s dilemma, Peirson and his team analyzed patterns of gene expression in the brains of mice exposed to pulses of light during hours of darkness – a technique meant to mimic the effect of time zone changes.
Eventually, researchers were able to identify a gene called SIK1, which appears to act as a regulator for all of the body’s clock genes. When the SIK1 gene is activated, it prevents the body’s clock genes from automatically shifting to adjust to changes in light exposure or differences in time zone.
“When activated by light, levels of expression (in all of these clock genes) go up,” Peirson said. “Then SIK 1 is activated, and the levels go down again.”
Essentially, the SIK1 gene is the sole biological obstacle preventing people from easily adjusting to time zone changes. When Peirson and his colleagues deactivated this gene in mice, their ability to adjust to changes in light exposure changed dramatically.
“What we did in the study was block the activity to that (gene), and if you block that, you effectively do an experiment in a shift of a six-hour time frame difference,” Peirson said. “And animals can retrain in one to two days rather than five to six days.”
This discovery could lead to the development of a drug capable of shutting off the SIK1 gene in humans, improving their ability to adjust to time changes. Researchers believe this could have major health benefits, as the side effects of jet lag can be more debilitating than just an increased urge to nap.
“It’s actually been shown to (cause) quite a number of effects ranging from gastrointestinal problems to disruptions to mood and performance,” Peirson said. “…And there’s also increased risk for metabolic disorders, cardiovascular disease and even cancer… with long term circadian disruption caused by constant jet lag.”
However, researchers acknowledge that while deactivating the SIK1 gene showed no obvious adverse effects in mice, more research will need to be done before a drug is developed to switch off this gene in humans.
“You (do) want some sort of buffering mechanism to stop the clock,” Peirson said. “Your body is full of clocks, and you want to stop them all moving out of phase and responding to stimuli that aren’t really relevant.”