Review on January 12, 2010
Although it is well known that physical activity can benefit the body in numerous ways throughout life, exercise' effects on hormones and the risk of breast cancer has until recently been unknown. Often thought to reduce breast cancer and other hormone based cancers by reducing the movement of ovarian hormones around the body, research about exercise has never been fully address. That is until recently when a review of all the relevant research until today was complied to give a definitive answer to the queries surrounding exercise and breast cancer risk.
With information from Nurses' Health Study, research carried out in1975 and 1980 assessed women's weekly exercise routines and physical activity. All the women involved were aged between 30 and 55 and over the 16 year follow up, 3137 cases of invasive breast cancer were recorded. From this group 1036 cases occurred pre menopause and 2101 occurred post menopause.
The results of this study show that those women that participated in over seven hours of physical activity a week were at a much lower risk of breast cancer than those women who undertook under one hour of physical exercise. Researchers have speculated that this might be due to the reduction in ovarian hormones moving around the body which occurs when a person regularly exercises. A lack of physical activity can encourage such hormones to build up in one region, in some cases in the breasts.
When results were gathered in 1975, 1980 and 1994, the amount of physical activity each patient undertook was recorded in different categories in order to determine whether strenuous activity can better dispel the build up of hormones during menopause. Activity could be moderate, strenuous or vigorous and walking was found to be one of the most common forms of moderate exercise for women both pre and post menopause. Vigorous exercise was usually in the form of aerobics or cycling. The results of this study found that women who only walked but took this form of activity frequently were at the same lowered risk of breast cancer as those who took strenuous exercise frequently. Therefore frequent light exercise has similar benefits of more strenuous workouts, a reduced cancer risk of 15%.
As this review of research shows, there is only a slight reduction in breast cancer risk for women who have regularly exercised throughout their adult lives as opposed to those who don't. However this does not mean that regular exercise should be disregarded as women age. A healthy lifestyle is important to fight against heart conditions and a range of other age related diseases which may threaten a woman's life and it can stabilize hormones, reducing the severity of menopausal symptoms which can mar a woman's later years.