Exercise can lower your overall risk of cancer –
but only if you get a good night’s sleep
After my last week’s rant about focusing efforts to PREVENT cancer as well as CURING cancer, I was please to review a research study that did just that! The study examined the link between exercise and cancer risk, paying special attention to whether or not getting adequate sleep further affected a women’s cancer risk.
The U.S. Centers for Disease Control and Prevention calls sleep loss a growing and as yet an under-recognized public health problem, saying Americans are getting less and less slumber. The CDC said the percentage of adults reporting sleeping six hours, or fewer, a night increased from 1985 to 2006. In previous studies reported in “The Inconvenient Women”, the rates of “short duration sleep” are even higher in the female population.
A resent National Cancer Institute study, presented at the American Association for Cancer Research’s Seventh Annual International Conference on Frontiers in Cancer Prevention Research, reported that physically active women, who slept less than seven hours nightly, had a 47 percent higher risk of cancer than those who got more sleep.
James McClain, Ph.D., MPH, cancer prevention fellow at the National Cancer Institute and lead author of the study, said it is unclear exactly how getting too little sleep may make one more susceptible to cancer, but getting adequate sleep has been long associated with maintaining good health. “We think it’s quite interesting and intriguing. It’s kind of a first look into this. It isn’t something that has been widely studied,”, said McClain.
“Greater participation in physical activity has consistently been associated with reduced risk of cancer incidence at several sites, including breast and colon cancers,” said James McClain, and “Short duration sleep appears to have opposing effects of physical activity on several key hormonal and metabolic parameters, which is why we looked at how it affected the exercise/cancer risk relationship.”
The Maryland-based study involving 5,968 women, aged 18 years or older with no previous cancer diagnosis, confirmed previous findings that people who engage in regular physical activity are less likely to develop cancer. The women completed an initial survey in 1998 and were then tracked through the Washington County Cancer Registry and Maryland State Cancer Registry. McClain and colleagues followed the women for almost 10 years to determine the association between physical activity energy expenditure, sleep duration and incidence of overall breast and colon cancers.
First incidence of cancer occurred among 604 women, 186 of which were breast cancer cases. According to McClain, sleep duration altered the association between physical activity and cancer risk among this population. In terms of the amount of physical exercise the women got per week, researchers found that sleep appeared to play an important role in cancer risk.
Even though the exact mechanism of how exercise reduces cancer risk isn’t known, researchers believe that physical activity’s effects on factors including hormone levels, immune function, and body weight may play an important role.
“Short duration sleep” increases all levels of health risk
Sleep experts say chronic sleep loss is associated with obesity, diabetes, high blood pressure, stroke, cardiovascular disease, depression, cigarette smoking and excessive drinking.
McClain J. #B145. Presented at: AACR Seventh Annual International Conference on Frontiers in Cancer Prevention Research; Nov. 16-18, 2008; Washington.