Many people are affected by cancer, either directly, or because they know somebody who has the disease. But thankfully, there are some lifestyle measures you can take to reduce your risk.
Each year in the UK, about a third of a million people are diagnosed with cancer. The four most common cancers (lung, breast, bowel (colorectal) and prostate) make up over half of all these cases. It is estimated that more than one in three of us will develop some form of cancer at some point in our lives.
Cancer is a complex disease and there are many factors that influence whether or not an individual develops cancer. These includes exposure to certain risks such as smoking, a person’s genetic make-up and even the country (and hence the environment) where a person lives. For example, smoking 20 cigarettes a day increases lung cancer risk by 20-40 times (a 2,000-4,000% increase in risk!).
Diet can also affect risk of some types of cancers, although the effect is far less than with smoking. The strongest links are with some cancers of the digestive tract – the mouth, throat, stomach and large bowel (colon) - and some hormone-related cancers such as breast cancer. It is estimated that approximately 30% of cancers in Western countries (such as the UK) could be prevented if people changed their dietary habits.
This section provides a summary of how diet and physical activity can affect your cancer risk. The tips on the next page have been produced to help you reduce your risk of cancer.
Smokers increase their risk of lung, mouth and throat cancers by 20-40 times compared to non-smokers. Smoking is the strongest predicator of risk amongst the lifestyle factors associated with cancer.
Being overweight or obese also increases a person’s risk of developing a number of different cancers, including cancers of the oesophagus (the tube leading from your mouth to your stomach), colorectum (or bowel), pancreas, endometrium (lining of the womb), kidney, gallbladder and breast (in post-menopausal women). For example, obesity increases the risk of colon cancer by 50% in men and 25% in women and about 17,000 cases of cancer in the UK are linked to being overweight. Try to make sure your body mass index (BMI) stays within the healthy range of 20-25; if possible at the lower end of this range. This can be done by eating a healthy varied diet and being physically active.
Not only does being physically active help you to control your weight, but it has additional benefits that can help reduce your cancer risk, such as increasing the frequency of your bowel movements and enhancing your immune system. Research consistently shows that physical activity can help to reduce the risk of colon, endometrial (womb) and postmenopausal breast cancers (independent of body weight), as well as helping to protect against the cancers that are linked to being overweight and obesity.
To help reduce your risk of cancer, aim to include in your daily routine some moderate intensity physical activity, for at least 150 minutes over the week in bouts of 10 minutes or more. Physical activities to improve muscle strength that works all major muscle groups (i.e. legs, hips, back, abdomen, chest, shoulders and arms) should be carried out on at least two days per week. Try and incorporate physical activity into your daily routine: for example take a brisk walk in your lunch break, use the stairs instead of the lift, or get off the bus one stop before you usually do and walk the rest of the way to your destination.
In addition to smoking, alcohol is one of the main risk factors for cancers of the mouth, throat and oesophagus. Alcohol is also one of the main diet-related risk factors for liver cancer, and it can increase the risk of breast cancer in women and colorectal cancer, especially in men. To help reduce your risk of developing these types of cancer, try to limit your alcohol consumption to no more than 14 units of alcohol per week (half a pint of 4% lager,= 1 unit, a small glass of wine (125ml) = 1.5 units, single spirit and mixer = 1 unit). If you do drink as much as 14 units per week, it is best to spread this evenly over three days or more (rather than having one or two heavy drinking sessions).