For decades, people with prediabetes have been told to avoid high-sugar fruits like mangoes. But new research suggests that this tropical fruit, despite its natural sweetness, may actually help lower the risk of diabetes.
A randomized controlled trial led by clinical nutrition researcher Raedeh Basiri at George Mason University found that adults with prediabetes who ate one mango per day for six months showed improved blood glucose control, greater insulin sensitivity, and reduced body fat compared to those who consumed a lower-sugar granola bar daily.
The results, published in Foods in August 2025, challenge long-held assumptions about fruit sugar and metabolic health.
More than just sugar content
“It is not just the sugar content that matters, but the overall food context that matters,” said Basiri, an assistant professor in the Department of Nutrition and Food Studies. “The sugars naturally found in mangos are complemented by fiber, vitamins, and other nutrients that may provide protective health benefits.”
Mangoes contain about 32 grams of natural sugar per fruit—three times more than the 11 grams in a low-sugar granola bar. But unlike processed snacks with added sugars, mangoes deliver nutrients that appear to support blood sugar regulation rather than harm it.
The study is the first long-term clinical trial to demonstrate both metabolic and body composition benefits of mangoes in adults with prediabetes.
What the trial found
Researchers divided participants into two groups. One group ate a fresh mango daily, while the other consumed a low-sugar granola bar. Over six months, the team tracked glucose levels, insulin response, and body fat.
By the end of the trial:
- The mango group showed improved glycemic control
- Insulin sensitivity increased
- Body fat levels decreased
Meanwhile, the granola bar group saw no comparable benefits.
Implications for diabetes prevention
Nearly 100 million adults in the United States live with prediabetes, according to the CDC. For many, the focus on cutting sugar leads to avoiding fruits altogether. Basiri hopes her research will shift the conversation toward whole foods.
“The goal is to encourage people to include whole fruits, like mango, as part of healthy eating behaviors and practical dietary strategies for diabetes prevention,” she explained.
Her findings highlight the importance of looking beyond sugar grams alone. Processed foods marketed as “low-sugar” may not carry the same protective benefits as nutrient-rich whole fruits.
The study was funded by the National Mango Board, though the authors note the funders had no role in study design, data analysis, or publication.
