8 January 2013
People should cut the number of hours spent watching television – which add up to 13½ years over an average lifetime – to reduce their risk from chronic disease, World Cancer Research Fund (WCRF) has said.
As New Year resolutions are considered, the cancer prevention charity has warned that sedentary behaviour could lead to obesity, an important factor in increased risk of developing cancer. It is also associated with type-2 diabetes and heart disease.
Sedentary behaviour – when minimal energy is spent, such as when sitting or lying down – is not just the absence of physical activity but is a separate behaviour in its own right. It is prevalent in all aspects of life: workers can spend most of the day sitting at a desk; leisure time often consists of long hours in front of a television; and modern transport, whether public or private, also encourages sedentary behaviour.
Kate Mendoza, Head of Health Information at WCRF, said: “People often assume that sedentary behaviour is the same as physical inactivity. But someone can do the recommended amount of daily physical activity but still be sedentary – for example, by spending an hour at the gym, then sitting at their desk all day and on the sofa in the evening.
“With a labour-saving device for most tasks, a large proportion of the UK population spends a significant part of the day sitting down. If people were to reduce prolonged periods of sedentary behaviour they would reduce their risk of serious diseases, including cancer.”
WCRF’s Second Expert Report, published in 2007, found convincing scientific evidence that sedentary living causes weight gain and obesity, the second biggest cancer risk factor after smoking.
Other research estimates that up to 15½ hours a day are spent engaging in sedentary behaviour in developed countries and that the link to cancer lies in the physiological changes when the body is inactive for long periods.
A recent study by the British Heart Foundation National Centre for Physical Activity and Health (BHFNC) found that sedentary behaviour generally rises with age, with a marked increase from approximately 60 onwards. Studies have also shown that women are more sedentary up to the age of 40 but men have higher levels after 60.
Research into sedentary behaviour is a relatively new field, but interrupting prolonged periods of sitting or lying down is the key to avoiding unhealthy patterns. At work, regular breaks such as getting up to speak to a colleague or making a drink will reduce sitting time, while at home setting ‘quotas’ for watching television or using a computer can also help.
World Cancer Research Fund (WCRF) raises awareness that cancer is largely preventable and helps people make choices to reduce their chances of developing the disease.
This includes research into how cancer risk is related to diet, physical activity, and weight management, and education programmes that highlight the fact that about a third of cancers could be prevented through changes to lifestyle. For more information on the charity’s work, visit www.wcrf-uk.org
The WCRF report, called Food, Nutrition, Physical Activity, and the Prevention of Cancer: a Global Perspective, was launched in November 2007 and is the most comprehensive report ever published on the link between cancer and lifestyle. For more information, visit www.dietandcancerreport.org