Adding one avocado and a cup of mango each day improves vascular health indices and reduces key cardiometabolic risk factors in people with elevated blood sugar, suggesting a simple dietary shift could strengthen heart health long before diabetes develops.
In adults with prediabetes, daily inclusion of avocado and mango increases fruit consumption, diversifies nutrient composition, and improves vascular function associated with cardiovascular health. Image credit: Tomek Walecki.
The burden of type 2 diabetes and prediabetes is substantial and growing.
In the United States, more than one in three people have prediabetes, and as many as eight in ten adults do not know they have it.
Prediabetes is characterized by elevated blood glucose levels below the threshold for diagnosis of type 2 diabetes and hyperinsulinemia due to insulin resistance.
People with prediabetes are at high risk for type 2 diabetes and more likely to develop and have complications of endothelial dysfunction, leading to macrovascular and microvascular diseases.
Currently, the most cost‐effective treatment is prevention and is a major public health priority.
In the new study, Illinois Tech Professor Britt Burton-Freeman and colleagues asked adults with prediabetes to follow an Avocado-Mango (AM) diet — adding one medium Hass avocado and a cup of fresh mango to their daily meals and snacks for eight weeks.
A calorie-matched control group followed a similar diet, with avocado and mango replaced by calorically comparable carbohydrate-based foods.
Those on the AM diet saw meaningful improvements in blood vessel function, which supports healthy circulation, and diastolic blood pressure, a key factor in long-term heart health, compared to the control group.
Blood vessel function improved significantly in participants on the AM diet.
They experienced a significant increase in flow-mediated dilation (FMD) — a key measure of endothelial function (blood vessel health) — to 6.7%, compared with a decline to 4.6% in the control. This suggests a meaningful improvement.
Diastolic blood pressure also significantly improved, particularly among men.
In the control group, men saw an average central blood pressure increase of 5 points (mmHg), while those on the AM diet experienced a reduction of about 1.9 points — a difference that can be clinically significant if sustained.
These benefits occurred without changes in calorie intake or body weight, suggesting that nutrient-dense fruits like avocado and mango may support cardiovascular health without major lifestyle changes.
“This research reinforces the power of food-first strategies to help reduce cardiovascular disease risk, particularly in vulnerable populations like those with prediabetes,” Professor Burton-Freeman said.
“It’s an encouraging message: small, nutrient-dense additions — like incorporating avocado and mango into meals and snacks — may support heart health without the need for strict rules or major dietary overhauls.”
The AM group also saw increases in fiber, vitamin C, and heart-healthy monounsaturated fat — nutrients tied to cardiovascular wellness — without changes in calorie intake or body weight.
Select kidney function markers, such as estimated glomerular filtration rate (eGFR), also improved.
While no significant differences were found in cholesterol, blood sugar, or inflammation, the findings highlight the value of adding nutrient-rich fruits to the diet, especially for those at risk of type 2 diabetes and cardiovascular disease.
“Overall, increasing fruit intake, specifically avocado and mango intake, resulted in vascular function changes that are important in cardiovascular health in a population at elevated risk for cardiovascular complications,” the authors concluded.
Their paper was published in the Journal of the American Heart Association.
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Chelsea Preiss et al. 2026. Effects of Increasing Total Fruit Intake with Avocado and Mango on Endothelial Function and Cardiometabolic Risk Factors in Adults with Prediabetes. Journal of the American Heart Association 15 (4); doi: 10.1161/JAHA.124.040933
