Image: Kenski1970, courtesy Flickr
WASHINGTON — Our culture of sitting may be responsible for 173,000 cases of cancer each year, according to new estimates.
Physical inactivity is linked to as many as 49,000 cases of breast cancer and 43,000 cases of colon cancer a year in the United States, said Christine Friedenreich, an epidemiologist at Alberta Health Services-Cancer Care in Canada.
Breast and colon cancer appear to be the cancers most influenced by physical activity, according to the research we have to date, Friedenreich said, in presenting her findings here today (Nov. 3) at the American Institute for Cancer Research (AICR) conference.
But her findings also suggested that an estimated 37,200 cases of lung cancer, 30,600 cases of prostate cancer, 12,000 cases of endometrial cancer and 1,800 cases of ovarian cancer could be prevented if people were more physically active.
The work adds to a growing body of research indicating that prolonged sitting has lethal consequences, regardless of how active people are the rest of the day.
"It seems highly likely that the longer you sit, the higher your risk [of cancer]," said Neville Owen, head of behavioral epidemiology at the Baker IDI Heart and Diabetes Institute in Australia, who also presented findings at the meeting. Owen's study showed that U.S. adults, on average, sit 15.5 hours a day.
The amount of time we spend standing up and walking "makes up such a tiny sliver of a person's waking hours," Owen said.
However, there's good news. It seems that long, uninterrupted periods of sitting are what is most unhealthy, and that by frequently breaking up long bouts of sitting with just a few minutes of light exercise, a person can lower his or her cancer risk. Owen's study found that one- to two-minute breaks from sitting can reduce levels of molecules in the body that are linked with cancer risk.
[Don't Sit Tight: 6 Ways to Make a Deadly Activity Healthier]
This research reveals that there's more to physical activity than working out on a treadmill. Alice Bender, a spokeswoman for AICR, noted that someone who exercises 30 minutes a day — the recommended amount of physical activity — is really only active for 3 percent of his or her day.
While getting to the gym or doing other regular exercise is still important, it is not the whole story, Bender said. The AICR recommends we take small breaks from sitting during our day to "infuse the remaining 97 percent of [our] day with short periods of activity that can protect against many cancers," she said.
Exercise and cancer
In Friedenreich's study, postmenopausal women who engaged in moderate to vigorous daily exercise had lower levels of C-reactive protein in their bodies after one year compared with women who did not engage in this level of activity. Low levels of this protein have been linked to reduced breast cancer risk.
C-reactive protein is a marker of inflammation, an immune response that normally helps your body fight off infection. Chronically high levels of inflammation may damage cells and possibly increase cancer risk.
Using data from her study and previous work on cancer indicators, Friedenreich estimated that daily exercise reduced the risk of breast and colon cancer by 25 to 30 percent.
"For many of the most common cancers, it seems like something as simple as a brisk walk for 30 minutes a day can help reduce cancer risk," Friedenreich said.
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6 Comments
Add CommentUh-oh. Having been in the computer business for 15 years now, I had concluded definitively that computers are not good for humans. Except, of course, that they offer us the opportunity to google ubekibekibekistanstan and santorum.
Reply | Report Abuse | Link to thisBut I have to ask, what about lying on the couch and reading trash novels? Science never addresses my deepest concerns.
a possible source of this link is lymph flow, which helps dispose of toxic wastes in our bodies. Sitting would impede flow, using muscles promotes it.
Reply | Report Abuse | Link to thisThen how do you figure when i slowed way down because of a herniated disk, and did nothing but sit in front of my puter or TV, my overall health improved? Greatly!!!
Reply | Report Abuse | Link to thisWe would need a lot more information to make any kind of logical judgement. What was your lifestyle and diet like both before and after? What is the history of disease in your family?
Reply | Report Abuse | Link to thisYour post is very much like saying people 200 years ago ate carrots and now they are all dead. Eating carrots may not have anything to do with the deaths and life expectancy may have everything to do with it. Your failure to provide a complete medical history makes your post meaningless noise.
The topic is "sitting". I think my post said it all. When i stopped being active, i felt better. My back and legs stopped aching. Being on my legs all day was not a good thing. Some ppl are in a wheel chair their entire lives and it didn't kill them.
Reply | Report Abuse | Link to thisWhere does this leave bike riding?
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