Could resetting the body's clock help cure jet lag?
'On a four-hour flight, [the method] can modify your circadian rhythm by two hours,' says expert
*Originally published on April 29, 2024.
In a repurposed aircraft hangar at Downsview Airport in Toronto, Kritika Vashishtha pursues her cure for jet lag.
She shines specially created lights onto study participants as they sit inside a grounded former jet, now converted into a science laboratory.
Participants must remain seated in the plane for four hours. They may not consume caffeine, watch a movie, or even close their eyes. Trips to the bathroom are discouraged, but if they absolutely must go, they must wear sunglasses that block out blue colours of light.
Vashishtha, who completed her PhD in Aerospace Engineering this spring at Toronto Metropolitan University, has created a trick of light that fools human bodies into switching time zones while aboard an aircraft.
"It's a fundamental framework that I've created," explained Vashishtha. "It could be used in medical fields where you would create a personalized light schedule to treat circadian rhythm disruption."
The trick requires real-time measurements, artificial intelligence, and a window that regulates how much sunlight passes through. There is also a set of LEDs bathing the the eyes of the passengers in a colour of light that delivers the maximum stimulus to the pineal gland without causing discomfort.
Each of us has a pineal gland inside our heads. One of its most important jobs is to react to the light hitting our eyeballs, and accordingly convert the brain chemical serotonin into melatonin, the so-called 'sleep hormone.'
"If you're flying from L.A. to London, depending on when you fly, when you [arrive], you will have a jet lag of approximately eight hours," Vashishtha told CBC's IDEAS.
"Your internal body clock cannot really shift with the speed we are flying, so our body clocks remain still in the local time zone, whereas we are physically in our destination time zone. Essentially, you're going to have those two circadian rhythm curves."
Adapting to Mars
Vashishtha's research has proven that if an airplane can alter the type and quantity of light reaching a particular person, on a schedule adapted to that person's idiosyncratic internal clock, it can minimize the gap between those two circadian rhythms.
"The beauty of Kritika's research is that she proved that this system works," said Bruce Malek, an industrial designer at Bombardier Aerospace, which contributed to the direction and funding of the project.
"On a four-hour flight, she can modify your circadian rhythm by two hours. It's like your body has adjusted to the light at the destination by two hours," Malek added.
The newly graduated Vashishtha has joined a research laboratory at Harvard Medical School, where she plans to direct her discoveries towards making space travel easier on astronauts.
For instance, a future human settlement on Mars would need to reckon with the problem that our bodies expect a 24-hour day, while a day on Mars is closer to 25 hours long.
A lighting system geared towards helping the body reset its internal clock more easily could make this experience less disturbing to digestion, sleep, and other cyclical functions.
Listen to the full episode by downloading the IDEAS podcast from your favourite app.
Guests in this episode:
Kritika Vashishtha is a PhD graduate from Toronto Metropolitan University, and post-doctoral researcher at Harvard Medical School.
Bruce Malek is an industrial designer at Bombardier Aerospace.
Jamie Zeitzer is a professor of psychiatry and behavioural sciences at Stanford University. His research into sleep and circadian rhythms gave rise to a commercial product called the Lumos Smart Sleep Mask.
Jeanne Duffy is a professor of medicine at Harvard Medical School.
Rosemary Braun directs the Braun Lab within the department of molecular biosciences at Northwestern University, Illinois.
*This episode was produced by Tom Howell and Pauline Holdsworth. It is part of the series IDEAS from the Trenches, which showcases fascinating new work by Canadian PhD students.
