Most Queenslanders know that avoiding sugar-laden food and getting regular exercise is good for their health. But what if scientists could quantify the actual health benefit to be derived by the average person depending on potentially modifiable lifestyle factors, or their environment?
A new study by researchers at QIMR Berghofer has done just that, finding a sobering 38 per cent of cancer deaths in Australia each year are potentially preventable.
‘Cancer is the biggest cause of death in Australia,’ says QIMR Berghofer’s Deputy Director and head of the Cancer Control Group, Professor David Whiteman.
‘It claimed more than 44 000 lives in 2013 and caused untold grief and heartache to many more.
‘And while in many cases, cancer is tragically unavoidable, this study highlights what we’ve known for some time: cancer isn’t always a matter of genetics or bad luck.’
Scientists found about 16 700 deaths from cancer each year could potentially be avoided, the vast majority through lifestyle changes.
The study sourced cancer incidence and mortality data from the Australian Institute of Health and Welfare and the Australian Bureau of Statistics, with researchers calculating the risk of cancer dependent on exposure to one or more of eight modifiable factors.
‘By far the biggest preventable cause of cancer deaths in Australia is tobacco smoke,’ says Professor Whiteman.
‘Cancer caused by smoking and passive smoking killed 9921 people in 2013 and accounted for 23 per cent of all cancer deaths.’
Aside from both smoking and passive smoking, other factors that heightened the risk of cancer were a poor diet – low fruit, vegetable and fibre intake or eating too much red or processed meat – and drinking too much alcohol.
Scientists found being overweight or obese, not doing enough exercise and too much sun exposure all contributed significantly to the burden of cancer.
Infections like Hepatitis C and Human papillomavirus, and hormone therapies, such as menopausal hormone therapy, were also linked to an increased risk of cancer.
‘The other major factors were poor diet, being overweight or obese, and infections. Each of those factors was directly responsible for about five per cent of all cancer deaths in
2013,’ Professor Whiteman said.
‘Poor diet caused 2329 deaths from cancer, being overweight or obese 1990 deaths, and infections 1981 deaths.
‘In line with these findings, the cancers responsible for the largest numbers of potentially preventable deaths were lung, bowel, cutaneous or skin melanoma, liver, and stomach cancers.’
Professor Whiteman said the eight modifiable factors were responsible for 41 per cent of cancer deaths among Australian men and 34 per cent of cancer deaths in women.
‘The proportions of potentially preventable cancer deaths were higher among men than women because, on average, men smoke and drink more, spend more time in the sun, and don’t eat as well as women,’ he adds.
But Professor Whiteman said there was good news to be taken from the findings.
‘This study shows that in theory, about 17 000 cancer deaths could be prevented each year if people followed accepted guidelines to minimise their exposure to risk factors,’ he said.
‘There is a lot people can do to reduce their risk of developing and dying from cancer.’
Professor Whiteman said smokers should try to quit, while regular exercise was a big plus.
‘If you currently smoke, seek advice on how to quit,’ he says.
He said most Australians weren’t getting enough daily exercise.
‘Start introducing some simple physical activity into your routine and aim to maintain a healthy body weight,’ he said.
“Limit your intake of red and processed meats and look for opportunities to incorporate extra fruit, vegetables and fibre into your diet.”
‘Finally, always remember to protect yourself from the sun.
‘Even small improvements in these areas would substantially reduce the number of people who die prematurely from cancer each year.’
Percentage totals do not sum to 38% as lifestyle factors co-occur to cause cancer. Imagery is illustrative only and not to scale.