Women who spend a lot of their leisure time sitting may be at increased risk of multiple myeloma, breast and ovarian cancers, according to a study published in Cancer Epidemiology, Biomarkers, and Prevention.
The link between sitting time and cancer risk is relatively unstudied, despite extensive evidence suggesting a link between cancer prevention and physical activity.
Research is increasingly investigating the adverse consequences of spending a lot of time sitting, as our sitting time has increased in recent decades, due in part to changes in transportation and the widespread use of computers and video games.
The American Cancer Society say in their guidelines that while it is not clear how excess body fat, consuming too many calories and not getting enough exercise raise cancer risk, "there is no question that they are linked to an increased risk of many types of cancer and that they are a serious and growing health problem."
The society recommends that adults should get at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity activity each week, and that it is preferable if these bouts of exercise are spread throughout the week.
Children and teens, meanwhile, are advised to get at least 1 hour of moderate or vigorous intensity activity each day, with vigorous activity on at least 3 days each week.
The society adds that physical activity above anyone's usual level of exercise also carries many health benefits.
The American Cancer Society Cancer Prevention Study II Nutrition Cohort
The new study analyzed data from 69,260 men and 77,462 women who had not been diagnosed with cancer and who were enrolled in the American Cancer Society Cancer Prevention Study II Nutrition Cohort.
During this study, between 1992 and 2009, 18,555 men and 12,236 women were diagnosed with cancer.
The authors of the study found that the women in the study were more likely to develop multiple myeloma, invasive breast cancer or ovarian cancer if they spent longer times sitting. However, they did not find a link between the length of time men spent sitting and their risk of cancer.
"Longer leisure-time spent sitting was associated with a higher risk of total cancer risk in women, and specifically with multiple myeloma, breast and ovarian cancers, but sitting time was not associated with cancer risk in men. Further research is warranted to better understand the differences in associations between men and women."
However, Medical News Today reported on a study yesterday that found prolonged standing is also associated with health problems, such as fatigue, leg cramps and back ache. The authors warned that these types of sustained muscle fatigue can lead to serious joint problems and back pain.
Also yesterday, we looked at a study that examined why breast cancer survivors are more prone to weight-gain than cancer-free women. The study suggested that exposure to chemotherapy and a family history of breast cancer were potential drivers of this increased weight gain.