People who eat more fruits and vegetables may have a slightly lower risk of type 2 diabetes than people who don't, and getting a wide variety of those healthy foods may be key to avoiding the disease, according to a UK study.
The findings, reported in the journal Diabetes Care, do not prove that eating fruits and vegetables will ward off the condition, which is associated with obesity and old age, but researchers said it should give people yet more incentive to improve their diet.
The study of over 3,700 UK adults found that those who ate the most servings of fruits and vegetables in a week had a lower risk of developing type 2 diabetes over 11 years versus people who ate the fewest.
The diabetes risk was also lower among people who consumed a wider variety of fruit and vegetables, regardless of the actual quantity they ate.
This suggests that people should focus not only on how many servings they get each day, said senior researcher Nita Forouhi, of the Institute of Metabolic Science in Cambridge, UK.
“The finding on variety of intake is new and exciting, because it demonstrates that independent of the quantity consumed, we have the potential to gain additional and important benefits from choosing a mixture of different fruits and vegetables as part of a balanced diet,” she said.
One serving is equal to a half-cup of cooked vegetables or a medium-sized piece of fresh fruit.
For the study, her team looked at data from 3,704 adults aged 40 to 79 who were part of a larger study on nutrition and chronic diseases. Of those people, 653 developed type 2 diabetes over 11 years.
All of the study participants kept a week-long food diary at the study's start, and Forouhi's team found that those who reported the highest combined fruit and vegetable intake were less likely to develop diabetes over the coming year.
Of the one-third with the highest intake - typically about six servings of fruit or vegetables a day - 16 percent were diagnosed with type 2 diabetes compared with 21 per cent of the one-third of participants with the lowest fruit and vegetable intake, about two servings a day.
That low-intake group closely matches the average US diet.
Of course, people who eat a lot of fruit and vegetables may be different in a number of ways, Forouhi said, including weight, exercise levels, smoking habits and education.
But when her team accounted for those factors, a high intake of fruit and vegetables was still linked to a 21 percent lower risk of developing type 2 diabetes.
The researchers found a similar pattern when it came to variety. People who consumed 16 different types of fruit and vegetables per week, on average, were about 40 per cent less likely to develop diabetes than people who averaged eight types.
Variety may be key because that helps ensure getting a wide range of nutrients. This includes not only vitamins and minerals, but also fiber and plant compounds called phytochemicals, which are thought to help protect cells from damage that can lead to chronic disease.
To get a good variety, Forouhi suggested incorporating a range of colors into your fruit-and-vegetable repertoire - but this all needs to be part of a generally healthy lifestyle.