Adding one avocado and one cup of mango daily improves vascular health indicators and reduces important cardiometabolic risk factors in people with elevated blood sugar levels. This suggests that simple dietary changes can boost heart health long before diabetes develops.

The burden of type 2 diabetes and prediabetes is large and growing.

More than 1 in 3 people in the United States has prediabetes, and as many as 8 in 10 adults don’t know they have diabetes.

Prediabetes is characterized by elevated blood sugar levels below the diagnostic criteria for type 2 diabetes and hyperinsulinemia due to insulin resistance.

People with prediabetes are at increased risk for type 2 diabetes and are more likely to develop endothelial dysfunction and complications that lead to macrovascular and microvascular disease.

Currently, prevention is the most cost-effective treatment and is a major public health priority.

In a new study, Illinois Institute of Technology professor Britt Barton Freeman and colleagues asked adults with prediabetes to follow an avocado-mango (AM) diet. That means adding one medium Hass avocado and one cup of fresh mango to your daily meals and snacks for eight weeks.

A calorie-matched control group ate a similar diet in which avocado and mango were replaced with calorically equivalent carbohydrate-based foods.

The group consuming the AM diet had significant improvements in blood vessel function, which supports healthy circulation, and diastolic blood pressure, which is an important component of long-term heart health, compared to the control group.

Vascular function significantly improved in participants on the AM diet.

They had a significant increase in flow-mediated dilation (FMD), a key measure of endothelial function (blood vessel health), to 6.7%, compared to a decrease to 4.6% in the control group. This suggests a meaningful improvement.

Diastolic blood pressure also improved significantly, especially in men.

Men in the control group had an average increase in central blood pressure of 5 points (mmHg), while men on the AM diet experienced a decrease of about 1.9 points, a difference that could become clinically significant if it persisted.

These benefits were achieved without changes in caloric intake or body weight, suggesting that nutritious fruits such as avocado and mango may support cardiovascular health without making major lifestyle changes.

“This research strengthens the power of food-first strategies to help reduce the risk of cardiovascular disease, especially in vulnerable populations such as pre-diabetics,” said Professor Barton-Freeman.

“This is a reassuring message. Small, nutrient-dense additions, such as incorporating avocado or mango into your meals and snacks, may support heart health without requiring strict rules or major changes to your diet.”

The AM group also had increases in fiber, vitamin C, and heart-healthy monounsaturated fats (nutrients associated with cardiovascular health), with no change in caloric intake or body weight.

Some kidney function markers, such as estimated glomerular filtration rate (eGFR), also improved.

Although no significant differences were found in cholesterol, blood sugar, or inflammation, the findings highlight the value of adding nutrient-rich fruit to your diet, especially for people at risk for type 2 diabetes and cardiovascular disease.

“Overall, increasing fruit intake, particularly avocado and mango intake, led to changes in vascular function that were important for cardiovascular health in populations at high risk for cardiovascular complications,” the authors concluded.

their paper Published in American Heart Association Journal.

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chelsea price others. 2026. Effects of increasing total fruit intake with avocado and mango on endothelial function and cardiometabolic risk factors in prediabetic adults. American Heart Association Journal 15(4);doi: 10.1161/JAHA.124.040933