While there are many factors that play into your predisposition towards certain cancers – genetics, environment, and lifestyle factors all can heavily influence whether or not you develop some form of the disease – there have been many studies on the role that regular exercise can play in preventing specific forms of cancer.
The results of these studies are often mixed, but it has become clear that there are certain types of cancer for which regular physical activity is a viable preventative measure that anyone can take.
Let’s have a look at what science can tell us about the relationship between exercise and cancer prevention.
1. Endometrial Cancer (Uterus)
Many studies have been done on the relationship between endometrial cancer development and regular exercise. About 20 recent studies have been dedicated to exploring the role that physical activity has on reducing endometrial cancer risk.
“The results suggest an inverse relationship between physical activity and endometrial cancer incidence,” say researchers at the National Cancer Institute.
“These studies suggest 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.”
Researchers believe that the relationship is primarily due to how changes in body mass and metabolism levels can affect hormones such as oestrogen(1).
2. Colorectal Cancer
A recent paper published in the journal Recent Results In Cancer Research outlines the discoveries made in the past two decades of colorectal cancer research, including the discovery that diet and exercise can play a major role in preventing colorectal cancer.
“Physical inactivity and to a lesser extent, excess body weight, are consistent risk factors for colon cancer,” the author writes.
“Diet and nutritional factors are also clearly important.”(2)
Current research indicates that between lifestyle factors and regular screening, early detection and prevention of colorectal cancer is feasible in many cases.
3. Prostate Cancer
While some researchers remain divided on whether or not exercise can have a preventative effect on the development of prostate cancer, there is research to back up the claim that it does.
Prostate cancer has the distinction of being the most commonly diagnosed cancer in men, so there has been much focus in recent years on potential preventative measures that individuals might be able to take to lower their risk for developing the disease.
A recent review in the West Virginia Medical Journal examines the evidence to date that exercise can result in an overall improvement in quality of life, which in turn can lead to more favourable outcomes in cancer treatment, and improving cancer survival outcomes.(3)
4. Breast Cancer
While family history and environmental factors remain significant in the development of breast cancer, exercise can go a long way to delaying the onset of the disease and even preventing its development.
A 2011 review found that across studies on exercise and breast cancer prevention, “there was a 25% average risk reduction amongst physically active women as compared to the less active women.”(4)
Even women with mutations in the BRCA-1 gene, which predisposes some women to breast cancer, may be able to delay the onset of the disease with a regular exercise regiment.
5. Lung Cancer
Lung cancer has one of the highest cancer mortality rates world wide, so any means of reducing its impact are definitely important.
A 2011 review of recent research in the journal Recent Results In Cancer Research discusses the emerging evidence that physical activity has a role to play in reducing the risk of lung cancer, especially in smokers.
“Several plausible biological factors and mechanisms have been hypothesized linking physical activity to reduced lung cancer risk,” the authors write, “including: improved pulmonary capacity, changes in growth factor levels, and possible gene-physical activity interactions.”(5)
6. Ovarian Cancer
A 2011 review of epidemiological studies of the associations of physical activity with gynaecologic cancers – including ovarian cancer – from the journal Recent Results In Cancer Research found that physical activity, including low-level physical activity like gardening and housework, may reduce one’s risk of developing various gynaecologic cancers.
“There is mounting evidence that sedentary behaviours such as sitting time probably increase risk of endometrial and ovarian cancers,” the review states.
“The biologic evidence provides strong support for a protective role of physical activity on cancer of the endometrium, and moderate support for cancer for the ovaries, as these cancers have a strong hormonal etiology.”(6)
Obviously there are many health benefits to leading an active lifestyle. But until recently, science hadn’t been able to provide us with hard evidence that cancer prevention was one of those benefits.
Now it’s clear that, while an active lifestyle won’t completely eliminate your risk of all cancers, it does have a role to play in helping prevent or delay the development of some of the most common – and deadly – forms of the disease.