By Dr Cory Couillard
Cancer is one of the most pressing health challenges, yet about one third of the most common cancers could be prevented through eating a healthy diet, being physically active, and maintaining a healthy body weight.
Scientists are still investigating how being physically active prevents some cancers but numerous studies show that it balances hormones, strengthens one’s immune system, and promotes a healthy digestive system. Experts agree that maintaining a healthy body weight throughout life is one of the most important ways to protect against cancer as well as a variety of other chronic diseases.
According to the World Cancer Research Fund (WCRF), being overweight or obese increases the risk of some cancers. Overweight and obesity also increases the risk of conditions including high cholesterol, high blood pressure, stroke, type 2 diabetes, and coronary heart disease.
In their report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective, there is convincing evidence that physical activity protects against colon cancer, post-menopausal breast cancer and endometrial cancer.
The World Health Organisation’s website states that physical inactivity is the main cause of up to 25 per cent of breast and colon cancers. Additionally, a series of studies that were published in The Lancet describes how physical inactivity levels cause 1 in 10 deaths worldwide.
Harvard researchers state that between 500 000 and 1.3 million lives could be saved each year if physical inactivity rates were to go down by even 10 to 20 per cent. These staggering statistics demonstrate how physical inactivity should be considered a pandemic and that it should be treated like any other infectious-disease pandemic would be.
To address this growing concern, it’s important to try to understand why certain people and groups of people are physically active while others are not.
Studies show that being physically fit balances hormones, strengthens one’s immune system and promotes a healthy digestive system. PHOTO/AFP/Getty Images
Adrian Bauman, a researcher from the University of Sydney in Australia, found one’s health status, being male, young or wealthy tend to make people more physically active, as does family and societal support for physical activity.
Time spent watching television and on the computer is another significant concern. Children often watch television for more than three hours a day, and they are likely to be exposed to the heavy marketing of high-energy foods. Statistics indicate that overweight that starts in childhood is likely to be followed by overweight and obesity in adulthood.
Urbanisation, rapidly growing cities, and poverty are other significant challenges that have caused people to become increasingly sedentary. As with overweight and obesity, sedentary ways of life are now common, if not usual, in most countries.
It has been estimated that physical inactivity levels could be reduced by 31 per cent through improved environmental interventions, including pedestrian- and bicycle-friendly urban land use and transport, leisure and workplace facilities, and policies that support more active lifestyles.
Moderate physical activity is needed for all – regardless of weight, health condition or age – to achieve optimal health and fight off cancer. People whose work is sedentary should take special care to build moderate and vigorous physical activity into their everyday lives.
Strive to get at least 30 minutes of moderate physical activity on most days of the week – the more the better. As fitness improves, aim for 60 minutes or more of moderate, or for 30 minutes or more of vigorous physical activity every day.
Dr Couillard is an international health columnist that works in collaboration with the World Health Organization's goals of disease prevention and control. Views do not necessarily reflect endorsement.
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