It's the third biggest cause of death in Australia (and now among the leading causes of death globally). And while death rates are coming down for some cancers, cancers are difficult to treat unless they're caught in the early stages. This is because by and large, we're still using surgery as the main treatment approach and when the cancer spreads, surgery is much less effective.
But a lot of cancer is preventable, according to a panel of experts who've reviewed the available scientific evidence about cancer, diet and exercise, and come up with some guidelines as to how we can lower cancer rates.
Over five years, scientists working for the World Cancer Research Fund (WCRF) from nine universities in four countries looked at the available research and published their findings in a report called Food, Nutrition, Physical Activity, and the Prevention of Cancer. There's a summary of it and an editorial in last month's British Medical Journal by a professor of cancer research at Oxford University. But if you don't have time to read that, or the report itself, here follows a summary.
What emerges is that for all our progress in medical science and technology, we still don't know much about cancer. We know how it happens – a genetic mutation in a cell's DNA causes it to reproduce out of control. But why it happens, and why some organs in some people and not others, is largely a mystery.
We do know that our lifestyle has a lot to do with whether this happens and in whom – very few cancers are actually inherited. So modifying our lifestyle will reduce our chances of cancer by up to a third.
First, we need to do something about obesity – it's a major cause of cancers of the oesophagus, colon and rectum, pancreas, breast, endometrium, and kidneys. Our body mass index should ideally lie between 21 and 23. Instead, the Australian average is about 27 – too high, and it's been that way since the 1940s. So we need to shed those kilos with exercise and caloric restriction – a weight loss diet.
Secondly, exercise. Quite apart from helping to lose weight, being fit seems to have an anti-cancer effect in itself. The researchers recommend 30 minutes of moderate physical exercise – like brisk walking – a day, and once we're fit, then 30 minutes of vigorous physical activity or 60 minutes of moderate exercise a day.
Next, our dietary intake. We need to be careful about how much alcohol we drink – it increases the risk for cancers of the mouth, pharynx, larynx, oesophagus, colon and rectum, and breast; and also causes cirrhosis, which raises the risk of liver cancer. Men shouldn't drink more than two standard drinks of alcohol a day and women no more than one a day.
What about fruit and vegetables? They probably protect against several cancers, though it's hard to say just which ones or why fruit and vegetables are protective. We should eat at least five portions of vegetables and fruits each day, the researchers say. The Australian dietary recommendations suggest five serves of vegetables and two serves of fruit each day. Most people eat only about three portions a day.
Probably the most surprising finding was that red meat and processed meat were convincingly linked to colorectal cancer. On average, if you eat large amounts of red or processed meat you have about a 30 per cent increased risk of colorectal cancer compared with someone who eats little or none. And the more meat you eat, the greater the risk. On average you shouldn't eat more than 300 grams of red meat a week. But Australian men eat more than 700 grams of red and processed meat a week, and Australian women almost 500 grams.
So we need to eat less, and instead eat mostly foods of plant origin. (Cutting down meat intake is also good for the environment – meat production uses large amounts of agricultural land and water, the researchers say.) On the other hand, meat is a terrific source of protein, as the meat industry never tires of reminding us, so there is a role for meat in the diet, but it should be limited.
Legumes such as beans, lentils and soybeans, which contain protein, are good substitutes. Cut out processed and preserved meats such as bacon, sausages, pate and salami as much as possible. The sulfites and other additives may cause colorectal cancer.
Foods high in folate may reduce the risk of cancer of the pancreas, and diets high in calcium may reduce the risk of bowel cancer, say the researchers. Other recommendations include:
limit consumption of salt
don't take vitamin supplements – you don't need them and some have been linked to cancer
mothers should breastfeed babies for the first six months: breastfeeding protects women against breast and other cancers.
Getting people to adopt all of the lifestyle measures won't be easy, the researchers conceded. But do what you can. It beats palliative care.
Link: http://www.abc.net.au/health/thepulse/stories/2007/12/13/2117657.htm
NOTE: This information was provided by the website above. All comments in this publication are in brackets and not in the original publication. I hope it helps you live a healthy life.
