Does an apple a day keep the doctor away — even for people with diabetes?

A new study published today in PLOS Medicine concludes that not only does fresh fruit help prevent diabetes, it also lowers risk of death and vascular complications for those already living with the disease.

“This is the first large prospective study demonstrating similar inverse associations of fruit consumption with both incident diabetes and diabetic complications,” the study authors wrote.

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Half-million people studied

Between June 2004 and July 2008, researchers recruited half a million adults aged 30 to 79 throughout different regions of China to take part.

Participants answered questionnaires and had their health monitored over the four-year period, allowing researchers to investigate links between diet and health.

“Among individuals who were free of diabetes at the start of the study,” the researchers wrote, “daily consumption of fresh fruit was associated with a 12 percent lower relative risk of developing diabetes.”

For those diagnosed with diabetes before the start of the study, eating fresh fruit more than three days a week produced a 17 percent lower risk of death from any cause.

The diet also produced a 13 to 28 percent decrease in risk of developing major complications from the disease such as heart disease and stroke, compared with individuals who didn’t consume as much fresh fruit.

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The sugar content in fruit

Sugar content in fruit can be high.

For example, a cup of figs can have up to 27 grams of sugar, while a cup of grapes can have 16 grams.

Therefore, medical opinion on fruit and diabetes has been mixed.

The study authors point out that previous medical literature shows contradictory conclusions. One study concluded that “higher fruit consumption was significantly associated with diabetes incidence.”

A separate European study concluded that there was no association between the two.

Finally, a recent meta-analysis of the issue said that higher fruit consumption was actually associated with a lower risk of diabetes.

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Different definitions of fruit

It can be perplexing, but there are reasons for the confusion.

Diets vary across the globe. That means the role — and even the definition — of fruit can change from place to place.

The authors note that many earlier studies were primarily conducted with Western populations, where fresh fruit consumption was often combined with processed fruit (think canned peaches).

Processed fruit can also include fruit juices, which have been shown to be a risk factor for diabetes. In fact, because of its sugar content — which is comparable to soda pop — even “100 percent” fruit juice is linked to weight gain and obesity, especially in children.

Another study, reported by The Guardian in 2013, said that individuals who replaced fruit juice with fresh fruit were able to significantly lower their risk of diabetes.

Current USDA guidelines recommend 1.5 to 2 cups of fruit per day for adult men and women in the United States. However, the recommendations do not specifically say “fresh fruit” — fruit juices, dried fruit, and processed fruits can also be included.

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Important distinction

Nutritionist Kristin Kirkpatrick told Healthline that the difference between fresh fruit and refined sugars comes down to one important thing: fiber.

When eating fresh fruit, sugar is attached to fiber and, “that makes a big difference in how aggressive the body responds to the carbohydrate.”

Under USDA guidelines, a cup of juice is equivalent to a cup of fresh fruit.

In healthy individuals that may be OK, but for people at risk for diabetes and obesity, comparing the two is like comparing apples and oranges.

The American Diabetes Association (ADA) has its own guidelines for fruit consumption, separate from the USDA. When contacted by Healthline, ADA officials pointed to the 2017 version of their publication Standards of Medical Care In Diabetes.

“As for all Americans, individuals with diabetes should be encouraged to replace refined carbohydrates and added sugars with whole grains, legumes, vegetables, and fruits,” the association wrote.

However, the ADA also does not make a significant distinction between the consumption of fresh and processed fruit as long as the final product doesn’t contain too much extra sugar.

On its website, fresh, frozen, and canned fruit are in the same category, and even fruits in “light syrup,” are included.