Food and drink cause as many as 80,000 cases of cancer each year in the UK, researchers warned today.
A third of the cases could be blamed on obesity and over-consumption of alcohol, according to experts.
But the remaining two-thirds are linked to diet aspects which are as yet largely unknown, a leading diet researcher said.
Delegates at the Cancer Research UK (CRUK) Senior Researchers Meeting in Harrogate were given the latest information about links between cancer and diet.
Dr Tim Key, a principal scientist on the European diet study EPIC, said it was possible that foods such a red meat and salty products might increase the risk of certain cancers, but the evidence was unclear.
‘Diet second only to smoking’
“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,” the researcher said.
Alcohol is said to be responsible for 6 per cent of cancers in the UK, such as cancers of the mouth, throat and liver.
Obesity is believed to be responsible for 5% of cancer cases, and is linked to breast, womb, kidney and bowel cancer.
Dr Key, from CRUK’s epidemiology unit at Oxford University, said: “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.”
The EPIC study, which started in the 1990s, is looking at the effects of diet on cancer rates across Europe.
Dr Key said that over the next five to 10 years they hoped to compare the diets of people who contracted cancer with those who did not.
“Our research is already suggesting some potential links and as time passes, we will find out more,” he said.
Professor Robert Souhami, CRUK’s director of clinical and external affairs, said: “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.”
Revision date: July 8, 2011
Last revised: by David A. Scott, M.D.