Can avocados help manage blood sugar for those with diabetes?

Written by Eliza Whitaker, MS, RDN, on April 22, 2024 — Medically Reviewed by Kristen Carli, MS, RD

New research suggests avocado consumption may help manage blood sugar levels and reduce diabetes risk.

Photo by Louis Hansel @louishansel/Unsplash

Summary

• A new study suggests that avocado consumption may lower fasting blood glucose and insulin levels in some people.

• Those consuming avocado appeared to have a reduced risk of developing type 2 diabetes.

• Dietary patterns can play a key role in preventing or managing type 2 diabetes.

Avocados are a versatile fruit that may contribute more to our health than previously thought.

A recent study was conducted to determine the metabolic impacts of regular avocado intake on fasting blood glucose and insulin levels and the rate of development of type 2 diabetes.

The study was published in The Journal of Nutrition.

Consuming avocados — a new approach to help manage diabetes?

As of 2021, 38.4 million Americans were diagnosed with type 2 diabetes mellitus (T2DM), and it’s estimated that 1.2 million Americans are diagnosed with new cases of T2DM every year. 

Emerging research is discovering a connection between T2DM and Alzheimer’s Disease, what some are referring to as type 3 diabetes, further emphasizing the importance of prevention and management of T2DM.

Amidst this worsening health landscape, some Americans' dietary habits have seen a notable shift, particularly toward increased avocado consumption.

The demand for avocados in the US tripled from 2001 to 2018, with 8 pounds consumed per capita. In 2018, 364 million pounds of avocados were grown in California, accounting for 93% of the avocados produced in the US that year.

This inclination towards avocado consumption is paralleled by a surge in academic and scientific interest, with a significant increase in research focused on understanding avocados' impact on health, particularly in the context of type 2 diabetes and other metabolic conditions.

In a 2023 study on adult Hispanic Americans, those who consumed avocados were less likely to develop T2DM than those who did not consume avocados at baseline. This association was even more significant in those with prediabetes. 

Another 2024 study observed that individuals with abdominal obesity who consumed one avocado daily for 26 weeks increased their adherence to the Dietary Guidelines for Americans, improving their overall diet quality.

Examining avocado intake in people with diabetes  

The present study was conducted using data from the Multi-Ethic Study of Atherosclerosis (MESA). The MESA followed adults across the U.S. beginning in 2000 with check-ins roughly every 18 months. 

Of those followed, researchers selected 6,220 participants to be evaluated for this secondary study. Of those 6,220 people, metabolic data was used for 3,438 randomly selected individuals.

The MESA Food Frequency Questionnaire (FFQ) was used to assess participants’ typical food intake over the year before the start of the study. 

Overall diet quality, independent of avocado intake, was assessed by ranking participants based on how closely their diet followed a Mediterranean style of eating. 

Participants were given a score of 0 or 1 for the following categories: vegetables, legumes, fruit, nuts, whole grains, fish, red meat, dairy, saturated fat to unsaturated fat ratio, and alcohol intake. Depending on their typical intake, participants could receive a score of 0-10. 

When we consume foods, they are broken down into smaller particles that the body can absorb. These smaller particles are referred to as metabolites — the products of metabolism. 

To create participants’ metabolic profiles, researchers used blood samples of 3,955 participants to look for metabolites signaling they consumed avocado.

Fasting blood glucose (fasting blood sugar) and insulin levels were measured. 

Researchers used the American Diabetes Association’s 2003 criteria to categorize participants into the following groups based on their fasting blood sugar levels:

• < 100 mg/dL = normoglycemia (normal blood glucose)

• 100–125 mg/dL = diagnostic for prediabetes (impaired fasting glucose)

• > 126 mg/dL = diagnostic for T2DM

Participants with a previous diabetes diagnosis, receiving diabetes medication, or meeting the criteria for diabetes diagnosis were classified as the T2DM group. The group was further divided into two subgroups: treated (with medication or insulin) and untreated. 

What the study results showed 

Of the total 6,220 adults who participated in the study, 35% reported they consumed avocados. 

Avocado consumers were younger, completed higher levels of education, were more likely to be Hispanic, and consumed more alcohol than non-consumers. 

The study revealed that consuming avocados may be associated with a modestly reduced risk of elevated fasting insulin levels, suggesting a potential benefit for blood sugar regulation. 

However, when adjusting for body mass index (BMI) alongside other factors, this reduced risk was no longer statistically significant, indicating that BMI may influence the relationship between avocado consumption and insulin levels.

Still, when researchers created metabolic profiles of participants, metabolic markers of avocado intake showed a highly significant correlation between lower fasting blood sugar and fasting insulin, with lower rates of participants discovering they had T2DM during the study. 

In the study's fully adjusted model, avocado intake was associated with decreased fasting blood sugar levels, lower fasting insulin levels, and a lower risk of developing T2DM at statistically significant levels.

Researchers concluded that avocado consumption's impact on fasting insulin and blood sugar levels will vary from person to person and may be influenced by their baseline blood sugar levels.

However, they found a strong association between the observed metabolites of avocado intake and lower levels of fasting blood sugar and fasting insulin, as well as a lower incidence of T2DM regardless of whether or not the participant had high or low blood sugar.

Study limitations

Participants’ avocado intake was measured using an FFQ. FFQs allow researchers to track the general intake of a food item over a longer duration, such as a few months or a year. However, this questionnaire relies on the participants to self-report their intake, which may not always be accurate. 

Participants were divided into avocado consumers and avocado non-consumers. This could have resulted in those who consumed avocado on an infrequent basis being labeled as non-consumers, potentially leading to a source of error within the study.

The importance of individualized care

T2DM is a widespread condition that over 460 million people worldwide struggle with. Avocados aren’t the cure, but they may help some people control their blood sugar levels to prevent or manage T2DM.

It’s important to recognize that this study mentioned that the effects of avocado intake may vary from person to person.

This emphasizes the importance of receiving individualized nutrition care from a nutrition professional, such as a registered dietitian, to determine interventions that best support the health of your own body.

How avocados may aid blood glucose control

Avocados are high in monounsaturated fatty acids and fiber, both of which may help manage blood sugar levels. 

Eating high-fat meals leads to delayed increases in blood sugar, potentially requiring adjusted insulin doses. 

In addition, research shows the type of fat consumed may influence blood sugar, hemoglobin A1c (HbA1c), and insulin levels. Specifically, replacing carbohydrates with mono- or poly-unsaturated fats may improve various markers of blood sugar control and insulin sensitivity, whereas saturated fats appear to have a lesser impact. 

Still, further research is needed to determine the impact of different fatty acids on blood sugar control before recommendations can be made.

Fiber in the diet works a little differently. Fiber is an undigestable material we consume in our diets supplied by plant-based foods. Our body lacks the enzymes that break down different types of fiber. Without these enzymes, fibrous material will move through our digestive system, helping us feel fuller longer, providing bulk to stool, and promoting gut health. 

This undigestable fiber essentially traps carbohydrates, so our body cannot digest and absorb them because we cannot digest the fiber surrounding those carbohydrates. That doesn’t mean we don’t digest and absorb any carbohydrates from fruits and veggies, but that there are some carbohydrates our body won’t absorb.

When fiber moves undigested into the large intestine, it is fermented by the bacteria living there. This fermentation process conducted by bacteria and microorganisms in the small intestine produces short-chain fatty acids, like butyrate. 

Butyrate acts as an inhibitor of the enzyme histone deacetylase, meaning that it stops the enzyme from working. This process may be beneficial for blood sugar homeostasis and is similar to the function of the medication Metformin, which is used to help manage blood sugar levels in those with T2DM.

Butyrate may also reduce insulin resistance, allowing the body to respond to insulin and maintain blood sugar homeostasis appropriately.

Expert tips on how to add avocado to your diet

Choosing a ripe avocado can sometimes be the most challenging part of incorporating avocados into your diet. Look for avocados that have very dark skin, as avocados with brighter green skin are less likely to be ripe. Gently squeeze an avocado to determine its softness. If it’s very hard and there is no give, the avocado is not ripe. If it's very soft and squishy, it may be rotten. You want to look for an avocado that feels soft but still has some structure.

Avocados should be stored at room temperature to promote ripening, but you can keep them in the refrigerator once they’re ripe to prevent them from becoming rotten. If you put them in the refrigerator while they are still hard, it will take much longer for them to ripen.

If you do bring home unripe avocados from the store, wrap them in newspaper and leave them on your counter for a day or two. You’ll be surprised at how quickly even the hardest avocados can ripen when wrapped in newspaper. 

Meal and snack ideas that contain avocado:

• Avocado toast

• Chocolate pudding made from avocados

• Guacamole with chips

• Avocado added to sandwiches or wraps

• Use avocado to top your favorite soups, chili, rice bowls, salads, or stir-fry

• Adding avocado to an omelet

If you aren’t big on the taste or texture of avocado, Patricia Kolesa, MS, RDN owner of Dietitian Dish, LLC, recommends blending avocados into smoothies and sauces or even using them as a fat alternative in baked desserts, such as brownies.

Michelle Routhenstein, MS, RD, CDE, CDN, preventative cardiology dietitian at Entirely Nourished, states that although incorporating avocados into a balanced diet can be beneficial for those with T2DM, pre-diabetes, or those at risk of developing T2DM, portion sizes, and overall dietary patterns must be considered as part of an individualized approach to diabetes management or prevention. 

The bottom line

Based on a recent study, avocados may aid in blood sugar management in those with and without T2DM. In addition to their impact on blood sugar regulation, avocados may also be cardioprotective. 

While avocados may support maintaining blood sugar levels, they are not a cure-all. Rather, consuming a balanced diet made of protein, carbohydrates, and fat from various food sources that also include fiber, vitamins, and minerals is the best way to promote the prevention of T2DM and other chronic diseases.

Further research is needed to understand the mechanisms behind avocado consumption and their impact on blood sugar. Talk to your doctor or registered dietitian about the best ways to manage blood sugar through diet. 

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  Dietitian Insights articles are authored by registered dietitians who utilize only high-quality sources, including peer-reviewed studies and reputable agencies, to provide the most up-to-date, evidence-based insights. Read our editorial process to learn more about how our content is medically reviewed and kept current and credible.

• Sources

  Wood AC, Goodarzi MO, Senn MK, et al. Associations between Metabolomic Biomarkers of Avocado Intake and Glycemia in the Multi-Ethnic Study of Atherosclerosis. J Nutr. 2023;153(10):2797-2807. doi:10.1016/j.tjnut.2023.07.013

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Note: All information in this article is for educational purposes only and should not be interpreted as medical advice. The reader should consult with a healthcare provider before using any supplements or making any dietary or lifestyle changes. Read the full medical disclaimer.