Sitting Down Often Could Put You at Risk for Cancer

High levels of sitting time increased risk of some cancers

(RxWiki News) Spending a lot of time sitting down has been found to increase the risk of chronic disease and death. New research says that excess sitting time can be even more detrimental to a person's health.

A recent study review found that high levels of time spent sitting increased the risk of colon, endometrial and lung cancer versus low levels of time spent sitting.

The researchers discovered that TV viewing time was the most detrimental type of sitting behavior.

"Tell your doctor how much time you spend sitting down."

The lead author of this study review was Daniela Schmid, PhD, MSc, from the Department of Epidemiology and Preventive Medicine at the University of Regensburg in Regensburg, Germany.

The review included 43 previously published studies on the association between sitting time and risk of cancer.

All the studies were published through February 2014, with 12 studies focusing on breast cancer, nine on colorectal cancer (colon and rectum), eight on endometrial cancer (lining of the uterus), five on ovarian cancer, three on lung cancer, three on prostate cancer, four on gastric cancer, three on esophageal cancer (stomach and esophagus), three on testicular cancer, one on kidney cancer and two on non-Hodgkin lymphoma.

There were a total of 4,068,437 study participants.

The researchers of the individual studies gathered data on TV sitting time, recreational sitting time, occupational sitting time and total sitting time through questionnaires and interviews.

The findings showed that there were a total of 68,936 participants with cancer.

Sitting time was associated with higher risks of colon, endometrial and lung cancer.

The participants with TV viewing times in the highest levels of sitting time were 54 percent more likely to have colon cancer compared to the participants who had TV viewing times in the lowest levels of sitting time.

The highest levels of occupational sitting time increased the likelihood of having colon cancer by 24 percent versus the lowest levels of occupational sitting time.

The researchers discovered that those with total sitting time at the highest levels were 24 percent more likely to have colon cancer compared to those with total sitting time at the lowest levels.

The participants who watched TV in the highest levels of sitting time were 66 percent more likely to have endometrial cancer compared to the participants who watched TV in the lowest levels of sitting time.

Total sitting time at the highest levels compared to total sitting time at the lowest levels was associated with a 32 percent increased risk of endometrial cancer.

The findings revealed that overall sitting behavior in the highest levels of sitting time was associated with a 21 percent increased risk of lung cancer compared to overall sitting behavior in the lowest levels of sitting time.

With each two-hour increase in sitting time, the risk of colon cancer was increased by 8 percent, the risk of endometrial cancer was increased by 10 percent and the risk of lung cancer increased by 6 percent.

These increased risks were independent of physical activity, suggesting that long periods spent sitting still negatively affected the participants who were otherwise physically active.

Dr. Schmid and colleagues believe that TV viewing time affected the risk of colon and endometrial cancer more than other types of sitting time because people often eat junk food and drink sugary drinks while watching TV.

The amount of time spent sitting did not affect the risk of cancers of the breast, rectum, ovaries, prostate, stomach, esophagus, testes and kidney and non-Hodgkin lymphoma.

"There is much more to developing cancer and chronic disease than sitting. Although inactivity plays a part in our health and wellness, several major factors not considered in this study are diet, smoking and stress management," said Rusty Gregory, a personal trainer and wellness coach in Austin, Texas and author of "Self-Care Reform: How to Discover Your Own Path to Good Health."

"To accurately access time spent sitting as a cancer risk factor, you have to consider other lifestyle behaviors as well. For example, if someone spends a large amount of 'off' time sitting and watching TV in addition to sitting at work, they are more likely to neglect other healthy lifestyle behaviors as well," Gregory told dailyRx News.

"The good news is that if you start practicing healthy behaviors throughout the workday, you are more likely to practice healthy behaviors at night and on the weekends.

Gregory offered some ideas for those interested in boosting their work-day activity level at the office:

  • Run or jog in place
  • Perform jumping jacks for 30 seconds
  • Squats over your chair. Act as though you will sit in your chair. Just before you touch the chair, stand back up, fully erect
  • Walk up and the stairs instead of taking the elevator
  • Hit the floor and do push-ups, either on your feet or your knees.

"These exercises aren't meant to take the place of a regular workout, but to get the heart pumping a little bit and jump-start the metabolism," Gregory said.

The review by Dr. Schmid and team was limited because the definitions of high and low levels of sitting time in each individual study varied, and data was based off of self-report.

Also, some of the individual studies on occupational sitting  were specific to a type of work.

This study review was published on June 16 in JNCI: Journal of the National Cancer Institute.

Review Date: 
June 16, 2014