Regularly eating white rice can significantly increase the risk of type 2 diabetes, a study claims.

Researchers at the Harvard School of Public Health studied the connection between the rice, which is the most commonly eaten worldwide, and the risks of contracting the illness.

The authors of the paper, published in the British Medical Journal, analysed the results of four studies, two in China and Japan and two in the US and Australia.

They found a significant trend in both Asian and Western countries, with a stronger association among women than men.

White rice has high GI values (a measure of carbohydrate effects on blood sugar levels) - often connected with type 2 diabetes - and is eaten in far greater quantities in the East, with an average of four portions a day eaten in Asian countries. In the West the average is five portions a week.

The authors argue that white rice also increases risks because it lacks nutrients such as fibre, magnesium and vitamins, which are found in brown rice.

"A dose-response analysis showed that each serving per day of white rice consumption was associated with an 11 percent increase in risk of diabetes in the overall population," the study claims.

"The recent transition in nutrition characterised by dramatically decreased physical activity levels and much improved security and variety of food has led to increased prevalence of obesity and insulin resistance in Asian countries."

The authors recommend that people eat whole grains and avoid refined carbohydrates in an effort to cut down on the risks.

"The dose-response relations indicate that even for Western populations with typically low intake levels, relatively high white rice consumption may still modestly increase risk of diabetes," they add.

Bruce Neal, senior director of the George Institute for Global Health, Sydney, said: "Although over-consumption of energy and accumulation of excess body fat is a common cause of type 2 diabetes, diet almost certainly has other unknown effects and specific food with particular adverse effects may have a direct role in the development of type 2 diabetes."

However, although he claimed that the study shed new light on the relation between diet and diabetes he warned that determining causality was "problematic". He argued that much deeper analysis would be required.