Milan: Refined foods such as bread increase the risk of kidney cancer, according to new reaserach from Milan’s Institute of Pharmacological Research.

People who eat five slices of bread each day, for example, are nearly twice as likely to develop the disease compared to those who eat 1.5 slices.

The elevated risk is caused by an increase in blood sugar and insulin as a result of eating refined cereals which result in the growth of cancer cells. The researchers, whose work is reported in the International Journal of Cancer, recommend replacing refined cereals with whole cereals.

The researchers studied more than 2,300 Italians – 767 who had the disease and 1,534 who did not – and asked them detailed information about their diet over the previous two years.

The scientists found a clear link between eating lots of bread and the risk of getting the cancer.

Overall those in the group that ate the most bread – equivalent to 35 slices weekly or five a day – were almost twice as likely to develop the cancer as those who had just 11 slices a week – around one and a half a day.

In contrast, those who ate a high proportion of poultry, meat and vegetables had a lower risk of getting the kidney cancer.

The study did not establish exactly what in bread may be to blame, however the researchers believe it may be linked to the high Glycaemic Index of many types.

Foods with a high GI cause a draondmatic rise in blood sugar levels which leads to the release of insulin and in turn chemicals that can fuel cell growth.

The theory is that cancer cells use these chemicals and the glucose to fuel their own unchecked, and therefore dangerous, growth.

Past studies have also found women who follow a low GI diet after the menopause have a lower risk of breast cancer than those who have lots of high GI foods.

The diet is also advised for people with diabetes to help prevent peaks and troughs in blood sugar levels.

Lead researcher Dr Francesca Bravi said her study suggested a diet with fewer cereals and more vegetables may help reduce the risk of renal cell carcinoma.

‘On the basis of the study we can also suggest reducing the consumption of refined cereals and increase that of wholegrain ones’ she added.