Starchy diet 'linked to cancer'

Researchers in the United States believe women who combine this diet with being overweight and exercising rarely are most at risk of developing the disease.

They believe that this kind of diet boosts insulin levels in the body. High levels of insulin have been linked to pancreatic cancer.

The disease is difficult to treat and is one of the most lethal cancers. Around 7,000 people are diagnosed with the disease each year in the UK.

Dr Charles Fuchs and colleagues of Harvard School of Public Health in Boston, made the link after analysing results from the US Nurse's Health Study.

This study was established in 1989. It involves 89,000 nurses who carefully record their diet and habits and whose health is monitored.

Increased risk

The Harvard researchers found that women who ate lots of unrefined starches, such as white bread and potatoes, increased the risk of pancreatic cancer by 57%.

However, some nurses were at a higher risk of developing the disease.

Dr Fuchs said: "If you took women who were both overweight and sedentary, their risk was 2.5 times higher."

He urged women to look at their diets and to switch to healthier alternatives if necessary.

"The take-home message for women who are overweight and sedentary is that a diet high in starchy foods may increase their risk of pancreatic cancer," Dr Fuchs said.

"Substituting less starchy vegetables such as broccoli for potatoes and rice and snacking on fruit are some simple steps they can take to reduce this potentially serious health risk."

Dr Fuchs added that diets high in starchy foods have also been linked to heart disease and diabetes.

"There are good reasons to avoid diets that are rich in these foods because they are not only associated in this cohort with pancreatic cancer - they are also associated with and increased risk of cardiovascular disease, heart disease and diabetes," he said.

Studies have shown that high levels of insulin increase the risk of pancreatic cancer.

Dr Fuchs said: "In the laboratory, insulin promotes the growth of pancreatic cancer cells. We suspect that body states that maintain high levels of insulin increase pancreatic cancer's ability to survive and grow."

Further research

Dr Tim Key of Cancer Research UK welcomed the study but said further research is needed.

"It's a very plausible hypothesis. The rationale that there might be an association makes a lot of sense.

"It seems to be in line with what we do know about the effects of diet on the function of the pancreas.

"However, their results were not statistically significant and it needs to be replicated in other studies."

The study is published in the Journal of the National Cancer Institute.