Even a Little Exercise Could Cut Your Cancer Risk

To reduce your cancer risk, you don’t need to make it all the way to the gym: You could start by bringing in the groceries. 

People who recorded just under four minutes of vigorous movement every day had a roughly 17% reduced cancer risk compared with people who didn’t log any high-intensity movement, a study published Thursday in the journal JAMA Oncology concluded. The link was stronger for cancers in which exercise has previously been connected to lower risks, including breast, colon, endometrial and bladder cancer. 

The study followed more than 22,000 people who reported that they didn’t exercise but logged minute-long bursts of activity such as walking uphill or carrying shopping bags. It adds to evidence connecting physical activity to better health, even when the movement is modest.

“Short bursts of vigorous activity are clearly important for cancer risk at the population level,” said Elizabeth Salerno, a biobehavioral scientist at the Siteman Cancer Center at Washington University in St. Louis, who wasn’t involved in the research. “It’s never too late to get moving in small ways, whether that be parking farther away at the store or taking the stairs.”

Study participants who moved vigorously throughout the day might have been at lower risk for cancer to begin with, said William McCarthy, adjunct professor of health policy and management at the UCLA Fielding School of Public Health, who wasn’t involved in the study. 

“I would not assume that adults adverse to structured physical activity should be satisfied with running up the stairs several times a day as an effective cancer-prevention alternative,” he said. 

Exercise has been linked to lower risk of several cancers, and health groups recommend that adults get at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise each week to see a benefit. 

But many adults don’t work out regularly, and less is known about how movement in everyday life might influence a person’s risk. Past studies also often relied on people to report how much they exercised, making smaller bouts of activity hard to track. 

For the new study, researchers used activity data from UK Biobank, a database of health information from people in the U.K., including data from wearable fitness trackers. The average age of the 22,000 nonexercisers tapped for the study was 62. About 6% of participants didn’t record any spurts of high-intensity movement. 

Some 2,300 cancer cases, hospitalizations or related deaths occurred among the group over about seven years. The researchers found that logging around 4½ minutes of daily intense activity was associated with a more than 30% reduction in risks for cancers where a link has been established between exercise and lower incidence. The more movement, the lower the risk. 

“People do not have to do vigorous activity to get benefit,” said Dr. Anne McTiernan, a professor of epidemiology who studies cancer prevention at the Fred Hutchinson Cancer Center in Seattle, who wasn’t involved in the study. “The best exercise is something that people will do, and do regularly.” 

The study didn’t explore whether daily movement benefits people who are already hitting the gym, researchers said. 

The study participants were mostly white and the results might not apply to the general U.S. population, McTiernan said. People need a baseline of activity to be able to move vigorously even for a short time, she said, and people moving more could be healthier in general, explaining their lower cancer risk. 

Researchers accounted for risk factors including smoking status, diet, alcohol consumption and family cancer history but might not have fully disentangled the influences, said Dr. I-Min Lee, an epidemiologist at Brigham and Women’s Hospital and professor of medicine at Harvard Medical School, who co-wrote the paper.

“We need several pieces of the puzzle to make a jigsaw picture. This is a start,” Lee said. “What I hope comes through clearly is that physical activity does lower cancer risk.”

The team plans to continue researching whether the impacts differ by sex and how short bursts of activity compare to intentional exercise, said Emmanuel Stamatakis, a professor of physical activity and population health at the University of Sydney and lead author on the study.

Write to Brianna Abbott at [email protected]