Avocado fat molecule can reduce insulin resistance and help regulate blood glucose, study shows

31 Oct 2019 --- Avocados may hold the power to help manage obesity and reduce the risk of diabetes, according to a new study conducted at the University of Guelph, Canada. The mice study found that a fat molecule only present in avocados, avocatin B, can inhibit cellular processes that normally lead to diabetes. The study discovered how avocatin B counters incomplete oxidation in skeletal muscle and the pancreas to reduce insulin resistance. As nearly one in four Canadians is obese, this research found that the avocatin B molecule can help regulate blood glucose and safely inhibit this metabolic process, Professor Paul Spagnuolo, the study’s lead researcher tells NutritionInsight.

“This research highlights how avocatin B is an inhibitor of fatty acid oxidation. In the dosage and form we have provided, its use was not associated with any dose-limiting toxicity in our human trial. Moreover, it forms the basis for a Phase II clinical trial where we can test avocatin B directly in obese and diabetic patients,” explains Professor Spagnuolo. Once a dose or range of doses is determined, Phase II trials evaluate whether the drug has any biological activity or effect.

The research team were not surprised by the overall findings, but rather by the magnitude of the effect. Avocatin B being able to improve insulin sensitivity as robustly as it did provides solid evidence for its physiological benefits, notes the study, published in the journal Molecular Nutrition and Food Research. 

Conducting the studies 
The research team fed mice high-fat diets for eight weeks to induce obesity and insulin resistance. For the next five weeks, they added avocatin B to the high-fat diets of half of the study’s mice.

The treated mice weighed significantly less than those in the control group, showing slower weight gain. More importantly, Professor Spagnuolo says the treated mice showed higher insulin sensitivity, meaning that their bodies were able to absorb and burn blood glucose and improve their response to insulin.

Testing their findings in a human clinical study, the researchers gave avocatin B in the form of a dietary supplement to participants eating typical western diets. This was absorbed safely into their blood without affecting the kidney, liver or skeletal muscle. The team also saw reductions in weight in human subjects, although Professor Spagnuolo maintains the result was not statistically significant. 

Avocados are known as a superfood, but eating avocados alone should not be relied on entirely to aid with weight loss, research shows.“We want to stress that the benefit of this molecule is in its ability to help regulate blood glucose. Reductions in weight are likely a secondary effect. We realize that this is a desirable feature for most, however, urge caution for weight loss as the sole indication,” he affirms. He continues that larger clinical trials in overweight and insulin-resistant patients are required to build upon this research. 

Eating avocados alone would likely be ineffective, Professor Spagnuolo continues, as the amount of natural avocatin B varies widely in the fruit. The science behind this research is still unclear about exactly how avocatin B is digested and absorbed when consuming a whole avocado. However, he explains that his research team technically has the capacity to continue this research in-house, mainly analyzing study participants’ avocado consumption and measuring avocatin B in their blood. 

Future plans
Professor Spagnuolo notes the connection between avocados and obesity prevention was based on previous studies conducted with avocatin B. Moreover, a paper published in Cancer Research in 2015 showed that avocatin B targeted a specific molecular pathway in leukemia. 

“When we learned that this pathway was also altered in obesity and diabetes, which at the time was not an active area of focus in my lab, we reasoned that avocatin B might also be useful for this disease by targeting this similar pathway,” he explains.

 The University of Guelph research team received approval to sell a supplement containing their standardized dose of avocatin B from Health Canada. He says he will begin selling avocatin B in powder and pill forms next yearthrough SP Nutraceuticals Inc, a Burlington-based natural health products company.

“We are excited to be launching this product over the next few months. We want people to have the option to use this product as a supplement and hopefully benefit from it. As diabetes and obesity affect millions worldwide, we hope this will provide a foundation for future studies that will look to food-based molecules as possible pharmaceutics for the treatment and prevention of life-threatening chronic diseases.” 

The research team is also preparing for a Phase II clinical trial where they will test this product in overweight and insulin-resistant patients. 

By Anni Schleicher