Physically active are less likely to develop cancer
There is convincing evidence that physical activity reduces the risk for specific forms of cancer. A research led by Japanese Health Ministry put forth that individuals who are active physically are less likely to develop cancer than their sedentary counterparts or less active colleagues. The surveyed population was divided into four groups according to their ratio of individual working metabolic rate, or MET (metabolic equivalent), which was determined by the amount of time respondents spent sitting, walking, standing, sleeping and exercising. This research put forth that the men in the most active group of people surveyed had 13 per cent less risk of developing cancer compared with the least active group, and women in the most active group had a 16 per cent lower risk than their sedentary counterparts.
Physical activity reduces risk of various cancers
There is convincing evidence that physical activity is associated with a reduced risk of cancers of the colon and breast. Several studies also have reported links between physical activity and a reduced risk of cancers of the prostate, lung, and lining of the uterus (endometrial cancer).
Three large studies in Italy and the USA estimated that physical inactivity could cause 13-14% of all bowel cancer cases and 11% of breast cancer cases.
Another study published in the British Journal of Cancer showed that people who walked or cycled for an hour a day were 16% less likely to develop cancer, and those who walked or cycled for just half an hour a day were 34% less likely to die of cancer, and 33% more likely to beat the disease. The benefits of a physically active lifestyle go far beyond lowering cancer risk. They include lower risk of heart disease, high blood pressure, diabetes, and osteoporosis.
Reduced breast cancer risk with long-term physical activity
A study published in Archives of Internal Medicine showed that strenuous long-term physical activity decreases a woman's risk of invasive and in situ breast cancer. The findings of this study put forth that women who annually participated in more than five hours per week of strenuous activity had a lower risk of invasive breast cancer compared with the least active women. The biggest risk reduction has been seen in lean women who enjoyed recreational physical activity, as compared with obese women and those whose physical activity was work or housework-related. Researchers also found that women who participated in long-term strenuous or moderate physical activity had a decreased risk of estrogen receptor- (ER-) negative invasive breast cancer, but not of ER-positive invasive breast cancer.
While evidence from a study published in Journal of Cancer and epidemiology Prevention put forth that physical activity reduces breast cancer risk in both premenopausal and postmenopausal women, high levels of moderate and vigorous physical activity during adolescence may be especially protective. Although a lifetime of regular, vigorous activity is thought to be of greatest benefit, women who increase their physical activity after menopause may also experience a reduced risk compared to inactive women.
Exercise improves colorectal cancer outcomes
Many studies in the United States and across the world have consistently found that adults with increased physical activity can reduce their risk of developing colon cancer by 30-40 percent, relative to those who are sedentary, regardless of their body mass index (BMI), with the greatest reduction in risk among those who are most active. It is estimated that 30-60 minutes of moderate to vigorous physical activity per day is needed to protect against colon cancer.
Two new prospective, observational studies published in the Journal of Clinical Oncology offer compelling evidence that regular physical activity in the months following treatment may decrease the risk of cancer recurrence and death from colorectal cancer. In the studies, patients with early- to later-stage colorectal cancer (but not distant metastases) who engaged in regular activity after diagnosis decreased the likelihood of cancer recurrence and mortality by 40 to 50 percent or more compared with patients who engaged in little to no activity.
It is known that physical activity may protect against colon cancer and tumour development through its role in energy balance, hormone metabolism, insulin regulation, and by decreasing the time the colon is exposed to potential carcinogens.
Physical activity reduces endometrial cancer risk
Research suggests that regular exercise as well as routine activities such as walking for transportation or performing household chores can reduce a woman's risk for endometrial cancer. A study published in the Journal of Epidemiology and Prevention suggested that women who are physically active have a 20 percent to 40 percent reduced risk of endometrial cancer, with the greatest reduction in risk among those with the highest levels of physical activity. Changes in body mass and changes in the levels and metabolism of sex hormones, such as estrogen, are the major biological mechanisms thought to explain the association between physical activity and endometrial cancer.
Physical activity reduces lung and bowel cancer risk
Studies suggest an inverse association between physical activity and lung cancer risk, with the most physically active individuals experiencing about a 20 percent reduction in risk. Scientists have found that people who are involved in active jobs are less likely to develop bowel cancer. A large study published in the Journal of Cancer Epidemiological Markers concluded that people who are physically active can reduce their risk of bowel cancer by a quarter.
Thus, the overall risk of cancer can be reduced by physical activity. Keeping active is one of the best things that can reduce risk of many types of illnesses, including cancers and heart disease. The above discussed studies give us even more reason to make physical activity an important part of our lives.