HOW TO CUT YOUR RISK OF BOWEL CANCER
Diet and lifestyle changes could prevent up to 20,000 of the 42,000 cases diagnosed in the UK each year. Here’s how to reduce the risk, says JO WATERS
bOWEL (or colorectal) cancer is one of the most preventable types of cancer. Scientists have established it has strong causal links to poor diet, lack of activity, obesity, smoking and alcohol – and these are all things you can control.
Although you can’t alter some risk factors for bowel cancer, such as your family history, height (tall people are more likely to develop it) and having inflammatory bowel disease, you can change your diet and lifestyle.
“Just as alcohol can cause liver disease and smoking causes lung cancer, an unhealthy lifestyle and bad diet can raise your risk of cancer, particularly bowel cancer,” says Susannah Brown, senior scientist at the World Cancer Research Fund (WCRF).
“There are definitely things you can do to protect yourself and reduce your risk significantly. Because bowel cancer is so common there’s now a lot of research evidence on the causes.
“Only five to 15 per cent of cancer cases have a genetic cause. You can significantly influence whether you develop cancer or not in four key ways: keeping to a healthy weight, being physically active, not smoking and eating a healthy diet.”
WHO IS AT RISK?
Bowel cancer can occur in people of all ages but 80 per cent of those affected are over 60 and 95 per cent are over 50. Having a close relative with bowel cancer is a risk factor.
Tell your GP if you have/had a parent, brother, sister or child diagnosed with bowel cancer before the age of 50, or two or more of the above who have been diagnosed at any age, or other relatives who have a relevant inherited genetic condition. Other risk factors include being overweight, having Type 2 diabetes, smoking and drinking too much alcohol. A high intake of processed meat (such as bacon, ham and meat pies) may also increase your risk factors.
Those with a history of inflammatory bowel diseases (Crohn’s disease and ulcerative colitis) or those who have had previous polyps removed may also be at higher risk of bowel cancer.
Over the past 40 years survival rates have more than doubled in the UK, thanks to a greater awareness of the symptoms, earlier diagnosis due to screening and improvements in treatments.
According to the latest figures available from Cancer Research UK, the five-year survival rate for men with bowel cancer is 59 per cent and for women it’s 58 per cent. The earlier it’s diagnosed, the greater the chances of survival: those diagnosed with stage 1 bowel cancer (before it has spread beyond the bowel) have a survival rate of 98 per cent, while for those diagnosed at stage 4 (when it has spread) the figure is 40 per cent.
“Early diagnosis is critical for survival,” explains Professor Matt Seymour, Cancer Research UK’s bowel cancer expert, who’s based at the University of Leeds. “GPs and patients are becoming more aware of symptoms and acting more quickly than in the past.
“The national screening programme, introduced in 2006, means some cancers can be cured before they’ve caused any symptoms at all. And in our hospitals better standards of surgery, radiotherapy, chemotherapy, imaging and pathology are all improving patients’ chance of cure.”
DON’T BE SQUEAMISH ABOUT SCREENING
In the UK we have a national screening programme for people aged 60 to 74. You’ll be sent a home faecal blood test kit every two years and you simply send a sample off to the laboratory. This may sound off-putting but it’s perfectly hygienic and easy to do. It’s also a potential
life-saver. If traces of blood are found you’ll be invited for a colonoscopy, where a thin flexible tube with a camera on the end is inserted into the bowel to check for cancer.
The NHS is also rolling out a programme offering 55-year-olds a flexible bowel scope investigation: a 10-minute endoscopic test called a sigmoidoscopy. A camera examines the left side of the bowel (where 70 per cent of tumours are found) and looks for polyps that may develop into cancer.
Experts say the test will eventually have a big impact on mortality rates for bowel cancer. More cases will be prevented and it will allow bowel cancer to be detected at an earlier stage.
TRY THE ANTI-CANCER DIET
A 2017 WCRF report says there is strong evidence that eating the following foods reduces your risk:
FIBRE-RICH FOODS
Research shows that people who eat fibre-rich foods such as wholegrains, fruit and vegetables have lower rates of bowel cancer. “This is because fibre-rich foods reduce the transit time (passage through the gut) of potentially carcinogenic chemicals and reduce insulin resistance, which is believed to raise the risk of cancer,” explains Susannah. In March 2018 the National Diet and Nutrition Survey for the UK revealed that on average adults are eating only 19.1g fibre a day instead of the recommended 30g.
WHOLEGRAINS
“Unprocessed wholegrains break down into short-chained fatty acids in the gut and these have anti-inflammatory effects.
“As with other fibre-rich foods they reduce transit time and help prevent insulin resistance,” says Susannah. “Plus, wholegrains are a source of vitamin E, copper, zinc, selenium and bioactive compounds like phytoestrogens, which have plausible anti-carcinogenic effects.”
Try wholewheat pasta, brown rice, quinoa, buckwheat, millet, spelt and wholewheat couscous.
DAIRY (FOR WOMEN)
Calcium-rich foods such as milk, cheese and yogurt are probably also protective against bowel cancer, says the WCRF report. WCRF can’t recommend dairy products as being protective for men, however, as other research studies have found they raise the risk of prostate cancer.
FRUIT AND VEGETABLES
Studies show that consuming foods containing vitamin C may lower the risk of bowel cancer. Combine this with evidence that a low consumption of non-starchy vegetables and fruit may increase the risk. Citrus fruits, peppers, dark green vegetables, papaya, berries and kiwis are good for vitamin C. Include more fish in your diet for its anti-inflammatory properties (down to the omega-3s, found especially in oily fish). Have two servings a week and make one of them oily, such as salmon or sardines.
FOODS CONTAINING HIGHER LEVELS OF VITAMIN D
These foods (the best sources are oily fish, such as salmon and sardines, and eggs) are associated with a lower risk of bowel cancer. WCRF recommends people get their vitamins from diet rather than supplements. Look for vitamin D-fortified products such as breakfast cereals and bread.