A population-based Australian study found that adults who ate two servings of fruit a day had a 36% lower chance of developing diabetes within 5 years compared to those who ate less than a half serving of fruit a day.
The findings by Nicola P. Bondonno, PhD, and colleagues, were published online June 2 in the Journal of Clinical Endocrinology & Metabolism).
The study also showed that a higher fruit intake was associated with higher insulin sensitivity, which can help lower your blood sugar.
And eating more apples — but not citrus fruit or bananas, the two other fruits studied — was also associated with better outcomes.
“This indicates that people who consumed more fruit [especially apples] had to produce less insulin to lower their blood glucose levels,” Bondonno, from the Institute for Nutrition Research at Edith Cowan University in Perth, Australia, said in a statement from the Endocrine Society.
“This is important since high levels of circulating insulin (hyperinsulinemia) can damage blood vessels” which is”related not only to diabetes, but also to high blood pressure, obesity, and heart disease,” she said.
Fruit Juice Doesn’t Have Same Effect
The study supports the recommendation of the Australian Food Guidelines — two servings of fruit a day, where one serving is 150 grams, or roughly amedium sapple, orange, or banana, Bondonno said in an email.
However, fruit juice was not associated with better blood sugar or insulin levels, or lower risk of diabetes, possibly because of its relatively high sugar load and fewer beneficial fibers, the researchers said.
“Promoting a healthy diet and lifestyle which includes the consumption of popular fruits such as apples, bananas, and oranges, with widespread geographical availability, may lower [type 2 diabetes] incidence,” they concluded.
Lower 5-Year Odds of Diabetes
It is not clear how eating fruit may help to protect against developing diabetes, the researchers said.
They aimed to examine how fruit and fruit juice is related to blood sugar, insulin and diabetes at 5 years and 12 years in study participants.
Participants said how often they ate 10 different types of fruit, any type of fruit juice, and other foods, on a scale of 0 (never) to 10 (three or more times/day). The researchers then divided participants into groups based on their answers.
The most commonly eaten fruit was apples (23% of total fruit intake), followed by bananas (20%) and citrus fruit (18%). The other fruits each accounted for less than 8% of total fruit eaten, so they were not studied separately.
Compared with participants who ate less fruit, those who reported eating moderate and high amounts of fruit were more likely to be female and report exercising at least 150 minutes a week. There were also fewer smokers in this group While those who reported a moderate to high fruit intake also ate more vegetables and less red meat and processed meat, they consumed more sugar, according to the study.
Of 4,674 participants who had 5-year follow-up, 179 participants developed diabetes.
After adjusting for age, sex, physical activity, education, socioeconomic status and other factors, the researchers found that compared to participants who ate less fruit, those who ate a moderate amount had 36% lower odds of developing diabetes within 5 years.
Of the 3,518 participants with 12-year follow-up, 247 participants had diabetes, but there were no significant associations between fruit consumption and this longer-term risk of diabetes, possibly due to the small number of participants and events..