Posts Tagged ‘duration’

Can Working Night Shifts Increase Your Breast Cancer Risk?

Wednesday, July 10th, 2013

logo1267406_md New research published in online Occupational and Environmental Medicine concluded that working night shifts for 30 or more years doubles the risk of breast cancer and is not confined to nurses. Researchers assessed 1134 women with breast cancer and 1179 without the disease but of the same age to assess whether working night shifts increased the risk of breast cancer. Women who did various jobs were asked about their shift work over their entire work period and hospital records were used to determine tumor types. Around one in three women in both groups had worked night shift and results showed that those who worked up to 14 years or between 15 and 29 years did not have an increased risk of developing breast cancer.  However, those working 30 or more years were twice as likely to develop breast cancer after accounting for potentially causal factors regardless of being in health care or not,. The numbers of breast cancer cases involved in these results were small, however.  Factors accounting for these results may include melatonin, sleep disturbances, upset body rhythms, vitamin D and lifestyle differences. . The authors concluded “As shift work is necessary for many occupations, understanding which specific patterns increase breast cancer risk, and how night shift work influences the pathway to breast cancer is needed.?

Further Research on Exercise and Breast Cancer Risk.

Wednesday, July 4th, 2012

Recent research published in early online Cancer concluded that mild or intense  exercise and  either before or after menopause may reduce the risk of breast cancer. However, substantial weight gain many negate these results. This information adds to the existing information on exercise and breast cancer by elaborating on such questions as duration, frequency, and intensity and the influence of body type.

The study included 1,504 women with breast cancer (233 noninvasive and 1,271 invasive) and 1,555 women women without breast cancer who acted as controls. All were between age 20 and 98 years of age.

Results showed that women who exercised during reproductive or postmenopausal years had a reduced risk of developing breast cancer with those exercising 10 to 19 hours a week experiencing the greatest benefit of about 30% reduced risk. Exercise at all levels of intensity reduced the risk of breast cancer and seemed to preferentially reduce the risk of hormone receptor positive breast cancer (ER or PR positive) that is the most common type of breast cancer among American women.  When researchers looked at the joint effects of phy6sical activity, weight gain, and body size, they found that women who were active but who gained a significant amount of weight, especially after menopause, had an increased risk of developing breast cancer indicating that weight gain eliminates the beneficial effect of exercise on breast cancer risk.