Adopting a diet rich in whole grains, vegetables and fiber while cutting back on red meat and fats may reduce the risk of developing diabetes, results of a new study suggest.

"We now have some solid evidence to give dietary recommendations to help reduce risk of diabetes," study co-author Dr. Teresa T. Fung, of Simmons College in Boston, Massachusetts, told Reuters Health.

Fung and her colleagues hypothesized that certain dietary changes may be important for preventing diabetes. To investigate, they followed some 80,000 participants in the ongoing Nurses' Health Study from 1984 to 2002. During that time, the women completed five questionnaires about their eating habits, which were used to create a so-called "Alternate Healthy Eating Index" score.

The index measures diet quality according to nine components: fruits, vegetables, cereal fiber, nuts and soy, moderate alcohol drinking, the ratio of white meat to red meat, trans fat, the ratio of polyunsaturated fat to saturated fat, and the long-term use of multivitamins.

Overall, 5183 women in the study developed type 2 diabetes during the 18-year follow-up period. Women with the highest scores on the Alternate Healthy Eating Index, however, were 36 percent less likely than those with the lowest scores to develop diabetes, Fung and her team report in the medical journal Diabetes Care.

What's more, women whose scores on the index improved during the follow-up period, even within the last four years of the study, also had a lower risk of developing diabetes than did those with a consistently low score.

"Since a reduction of risk is seen after only a few years of changing from an unhealthy diet to a healthy one, it shows that it is never too late to try to reduce diabetes risk," Fung commented.

"However," she added, "it doesn't mean that people can put off improving their diet because it is difficult to predict the progression of diabetes development and the longer a person has been eating healthy, the more benefit."