Diet and cancer - the story so far
Diet is responsible for up to 80,000 cases of cancer each year in the UK, according to a leading researcher speaking at Cancer Research UK's conference in Harrogate.
Dr Tim Key, a principal scientist on the European diet study EPIC, says that around a third of these can be put down to alcohol and obesity alone.
However, Dr Key says that the exact causes of the remaining two thirds are largely unknown.
Dr Key, who is based at Cancer Research UK's Epidemiology Unit in Oxford, explains: "Research suggests that diet is second only to smoking as a cause of cancer. But the effects of our eating habits are complicated and we are only beginning to understand which foods contribute to the disease.
"What we do know is that alcohol consumption and obesity are important causes of cancer and, while alcohol consumption is increasing in UK women, obesity is on the rise in both sexes."
Overall, alcohol consumption is responsible for six per cent of cancers in the UK, while obesity is believed to cause five percent of cases.
Alcohol is known to cause cancers of the mouth, throat, food pipe and liver and the risk with alcohol is much higher if you also smoke. Alcohol also causes a small increase in the risk for breast cancer. Obesity contributes to breast, womb, kidney and bowel cancer.
Dr Key adds: "Other factors, such as red meat, preserved meat and salty foods may also increase the risk of certain cancers but the relationship is not yet clear."
Cancer Research UK along with the Medical Research Council are funding the English arm of EPIC, a Europe wide study of the effects of diet on cancer rates.
The study, which began in the 1990s, has enrolled half a million people in ten different countries, including 90,000 in England.
Dr Key says: "The EPIC study represents a major step forward. We have already been able to measure large differences in diet across Europe. Over the next five to ten years we can compare the diets of those who get cancer with those who don't.
"Our research is already suggesting some potential links and as time passes, we will find out more."
Cancer Research UK's Director of Clinical and External Affairs, Professor Robert Souhami says: "After giving up smoking, having a healthy diet and lowering alcohol intake are the most important ways of reducing the risk of cancer.
"The EPIC study is a very valuable project because it is beginning to tell us exactly which foods can help to prevent cancer and which should be avoided."
Notes to Editor
On average women are drinking an extra unit of alcohol each week compared to ten years ago. Obesity has increased by 39 per cent in women and 67 per cent in men over the last 10 years.
Advice on diet from Cancer Research UK:
- Eat a balanced diet that is low in fat and red meat and rich in fruit, vegetables, starchy foods and fibre.
- Try to eat at least five different portions of fruit and vegetables every day - they are excellent sources of vitamins and fibre.
- Eat high-fibre foods like wholemeal bread, wholegrain breakfast cereals and pasta, beans, peas and lentils.
- Eat smaller and fewer portions of red and processed meat - try poultry, seafood or beans instead.
- Be cautious with supplements - they do not add to a healthy balanced diet and high doses of supplements can cause harm.
- Try to maintain a healthy body weight by combining a balanced diet with regular exercise.
- Try to do half an hour's moderate activity at least five times a week.
- If you are a woman, drink no more than two units of alcohol each day.
- If you are a man, drink no more than three units of alcohol each day.