A breakthrough study published in the Open Access journal Nutrients by researchers from the Center for Nutrition Research at the Illinois Institute of Technology shows that eating just two cups of fresh mango per day could increase insulin sensitivity in people with chronic low-grade inflammation. The researchers carried out a clinical study to determine the effect of mangoes on insulin levels and inflammatory responses in the body.

“Managing blood glucose isn’t just about monitoring blood sugar levels—it’s about improving insulin sensitivity,” says Indika Edirisinghe, PhD, Professor of Food Science and Nutrition. “Our study suggests that adding fresh mangos to the diet can be a simple, enjoyable way for people who are overweight or have obesity to support better insulin function and reduce type 2 diabetes risk.”

The health benefits of mangoes

Mango is a tropical fruit packed with fibre, minerals, and nutrients. It has a common misconception as being unhealthy due to its naturally high sugar content. However, previous research on animals shows that mangoes may induce the production of anti-inflammatory markers, while human studies show mixed results.

Nonetheless, mangoes are full of key vitamins, such as vitamins A and C, which support the body’s immune response and bone and reproductive health. Research shows that these components can be beneficial at fighting heart disease. Mangoes also contain key antioxidants which clear accumulated oxidative stress in the body. High levels of oxidative stress can result in things like metabolic disease and cancer.

Furthermore, the high fibre content in mangoes ensures that the natural sugars present in the fruit are absorbed by the digestive system into the blood more slowly, preventing that initial spike in blood glucose levels. Therefore, the fruit may aid in promoting the regulation of insulin levels.

Insulin is a key regulatory hormone

Insulin is a crucial hormone secreted by the pancreas in response to rising glucose levels. Its key role is to regulate glucose levels in the blood. It does this by allowing cells to take up glucose via a key transporter protein called GLUT4, which is present on cellular surfaces. It also suppresses the liver from making more glucose.

Diabetes is characterised by high levels of glucose in the body, meaning that insulin is not working efficiently to regulate blood sugar levels. Chronic low-grade inflammation is a state in which the body is at a constant low level of inflammation and contributes to the manifestation of diabetes, which is a type of metabolic disorder.

Homeostasis of the blood is a tightly regulated system. This means that the blood’s pressure, volume, oxygen, carbon dioxide, pH and glucose levels remain within a narrow range to enable the body to function at an optimal state and carry out all necessary functions. When insulin is no longer working as it should, an excess of glucose remains within the bloodstream, which is known as hyperglycemia. If left untreated, this can cause significant damage to blood vessels, cells and organs.

The aforementioned study looked at how eating mangoes may contribute to increased insulin sensitivity, promoting more efficient regulation of blood glucose levels in those with chronic low-grade inflammation.

Study design

In the study, researchers carried out a randomized, placebo-controlled, single-blinded clinical trial over 4 weeks on 48 adults aged 20–60 who were overweight or obese with chronic low-grade inflammation. The researchers asked the participants to completely exclude mango from their usual diet one week before the study, and then carried out an oral glucose tolerance test at week 0. This test measures how well the body processes glucose.

They then asked the participants to consume two cups of fresh mango per day, and on each day, their vitals and body compositions were measured. This group was called the mango intervention group and was compared against a control group, which consisted of participants consuming a calorically similar product to mangoes called Italian Ice.

Insulin sensitivity was measured using the homeostatic model assessment of insulin resistance test, or HOMA-IR. The effect of mangoes on inflammation was measured by analysing inflammatory markers like IL-6, TNF-α, and hs-CRP.

Mangoes help improve insulin sensitivity

The study hypothesised that mangoes would improve insulin sensitivity by reducing inflammation, but the results showed that mangoes did not have a significant impact on inflammatory markers. However, insulin sensitivity was significantly improved after 4 weeks, suggesting the beneficial role that mango has to play in regulating how the body responds to insulin.

Dr. Edirisinghe comments on some of the study findings and their importance:

“The improvement in insulin sensitivity in the mango group, without changes in body weight, is noteworthy, which counters misconceptions about mangos’ natural sugar content and impact on obesity and diabetes,” says Edirisinghe. “These findings support previous research showing that eating mango does not lead to weight gain, and while the exact mechanism is still unknown, the role of improved antioxidant status from mango consumption may be the mediating factor on blood glucose control.”

Find out more

To find out more about food research and its effect on health and wellbeing, access the journal Nutrients, where all articles are free and available to read immediately. Alternatively, access the full journal list.