Email Print Share
November 5, 2020

Chronic jet lag impairs immune response, accelerates tumor growth

A new study sheds light on how circadian disruptions impact the body's ability to curb cancer growth. The research was performed by scientists at Virginia Tech and the National University of Quilmes in Argentina. It was supported by the National Science Foundation in the United States and the National Science Agency in Argentina.

Credit: National Science Foundation/Karson Productions

Off the clock.

I'm Bob Karson with the Discovery Files, from the U.S. National Science Foundation.

(Sound effect: jet flying sounds) When flying across time zones or working staggered shifts, most of us have experienced the dreaded (Sound effect: voice slows down) J E T L A G. Our natural circadian rhythms get (Sound effect: sproinggg) outta whack. Our internal clocks go out of sync with the environment, and that can (Sound effect: spaghetti western sting) (Sound effect: old west accent) cause a ruckus down in cell town.

An NSF-funded study out of Virginia Tech shows that for cancer patients, chronic jet lag can hamper the body's immune defenses and actually accelerate tumor growth.

(Sound effect: ticking) Every cell has its own set of molecular clocks that call the shots: When to grow, divide, decay. In cancer cells these often go (Sound effect: cuckoo! Cuckoo clock sound) cuckoo. Leaving tumor cells to their own devices -- to grow unchecked.

To shed light and dark on all this, the team tested 2 groups of mice with tumors. The control group got normal 12-hour day/night light cycles. The other group had their light conditions shift by 6 hours every 2 days that's like jet-lagging across 21 time zones a week! (Sound effect: cartoon mouse: "whew!") After a month, tumors in the jet-lag group grew 3 times the size of those in the control group.

The study helps explain why some tumors win the race when the environment and the body's clocks are misaligned.

My circadian clock has a 'snooze' button.

"The discovery files" covers projects funded by the government's National Science Foundation. Federally sponsored research -- brought to you, by you! Learn more at or on our podcast.

Images and other media in the National Science Foundation Multimedia Gallery are available for use in print and electronic material by NSF employees, members of the media, university staff, teachers and the general public. All media in the gallery are intended for personal, educational and nonprofit/non-commercial use only.

Images credited to the National Science Foundation, a federal agency, are in the public domain. The images were created by employees of the United States Government as part of their official duties or prepared by contractors as "works for hire" for NSF. You may freely use NSF-credited images and, at your discretion, credit NSF with a "Courtesy: National Science Foundation" notation.

Additional information about general usage can be found in Conditions.