The National Cancer Institute (NCI) at the National Institutes of Health affirms that the formation and advancement of cancer is linked to an ‘energy balance’, which is the collective and qualitative effect of factors, such as food, body weight, physical activity, and genetics, on our body. Health is influenced by fitness, which according to NCI is a key component of energy balance.
Most of us may not get the kind of physical exercise that our body requires through normal and routine daily activity. Numerous researches have established that regular exercise has potential health benefits that include providing an immunity boost, fighting various health conditions and diseases, helping to prevent cancer, and keeping one physically and mentally fit and healthy.
The U.S. Cancer Statistics Working Group in their 1999-2011 report says that colorectal cancer, which affects both men and women, is a leading cancer killer accounting for over 50,000 deaths in 2011. Various studies (Lee et al, 2006 and McTiernan et al, 2006) have reported that about 30-60 minutes per day of vigorous physical activity may help offer colon cancer protection. An increase in the duration, intensity, and frequency of physical activity seem to decrease the risk of such cancers by as much as 30-40%. It is believed that increased exercise and physical activities may assist in the better metabolism of hormones, balance the body’s energy, regulate insulin, and modify certain inflammatory and immune factors that may be linked to colon cancer.
Numerous researches all around the world (America, Europe, and Asia) highlight and affirm that women (both pre-menopausal and post-menopausal women), who are physically active throughout their life, have lowered risks of breast cancer. Moreover, the risk seems to decrease with parameters such as intensity, frequency, and duration of exercise. A moderate to high level of intense exercise or physical activity for about an hour is linked to decreased breast cancer risk. The same correlation holds true for endometrial cancer too, where greater physical activity is associated with reduced cancer risk in women; with the reduction percentage in the range of 20-40%. Women after menopause generally have a higher risk for endometrial cancer, and in such cases, may benefit from more physical activity.
NCI informs that although there is a positive correlation between lung cancer and increased physical activities and exercise, the relationship is unclear in the case of women when compared to men. In the case of prostate cancer, current studies are unable to establish a direct link between physical activity and cancer of the prostate. However, in one particular study (Giovannucci et al, 2005), it was suggested that vigorous physical activity, when performed on a regular basis, may help slow the progression of prostate cancer.
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Giovannucci EL, Liu Y, Leitzmann MF, Stampfer MJ, Willett WC. A prospective study of physical activity and incident and fatal prostate cancer. Archives of Internal Medicine 2005; 165(9):1005–1010.
http://www.cancer.gov/cancertopics/factsheet/prevention/physicalactivity (accessed on 12/19/2014)
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Helpful Peer-Reviewed Medical Articles:
Shann, F. (2000). Does physical activity prevent cancer. British medical journal, 321, 1424-1425.
Kushi, L. H., Byers, T., Doyle, C., Bandera, E. V., McCullough, M., Gansler, T., ... & Thun, M. J. (2006). American Cancer Society Guidelines on Nutrition and Physical Activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity. CA: a cancer journal for clinicians, 56(5), 254-281.
Thune, I., Brenn, T., Lund, E., & Gaard, M. (1997). Physical activity and the risk of breast cancer. New England Journal of Medicine, 336(18), 1269-1275.
Byers, T., Nestle, M., McTiernan, A., Doyle, C., Currie‐Williams, A., Gansler, T., & Thun, M. (2002). American Cancer Society guidelines on nutrition and physical activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity. CA: A Cancer Journal for Clinicians, 52(2), 92-119.
McTiernan, A., Kooperberg, C., White, E., Wilcox, S., Coates, R., Adams-Campbell, L. L., ... & Ockene, J. (2003). Recreational physical activity and the risk of breast cancer in postmenopausal women: the Women's Health Initiative Cohort Study. Jama, 290(10), 1331-1336.
Friedenreich, C. M., & Orenstein, M. R. (2002). Physical activity and cancer prevention: etiologic evidence and biological mechanisms. The Journal of nutrition, 132(11), 3456S-3464S.