Avocado-containing diet may improve glucose control in T2D

Following a diet that contains avocado appears to be beneficial to individuals with type 2 diabetes (T2D), being associated with lower average glucose levels.

In a study that involved up to 14,591 Hispanic/Latino adults, each daily serving of avocado was associated with 8.52-mmol/mol lower HbA1c (p=0.02) and 16.01-mg/dL lower fasting glucose (p=0.02) among participants with T2D. A typical serving size consisted of one-half of an avocado, providing 6.7 g of monounsaturated fatty acids (MUFA). [Nutr Metab Cardiovasc Dis 2023;doi:10.1016/j.numecd.2023.08.002]

Of note, body mass index did not modify the inverse associations of avocado intake with HbA1c and fasting glucose, according to the investigators.

“Although underpowered to detect significant effects, in those with untreated T2D, we observed an inverse association between avocado intake and HbA1c with a similar magnitude of effect as all participants with T2D (p=0.08),” they added.

Moreover, avocado intake had a favourable effect on insulin sensitivity and glucose metabolism in the untreated T2D subgroup. Each daily serving of avocado was associated with Each daily serving of avocado was associated with 7.95-point higher HOMA-%b scores (p=0.04), 2.99-point higher insulinogenic index scores (p=0.02).

“The association between avocado intake and HOMA-%b was slightly attenuated when controlling [for] BMI (p=0.06), but the association between avocado intake and insulinogenic index remained of a similar magnitude (p=0.01),” the investigators said.

Among participants with prediabetes, on the other hand, there were no associations found between avocado intake and glucose or insulin homeostasis.

Despite the lack of benefit for adults with prediabetes, “the results here suggest that a diet containing avocado is associated with better glucose homeostasis. Our overall pattern of results also supports emerging data that dietary advice should be tailored to an individual’s metabolic state and that optimal strategies may differ for those with vs those without dysglycaemia,” the investigators pointed out. [Ann Nutr Metab 2011;58:290-296; Ann Nutr Metab 2012;60:33; J Diabetes Mellit 2023;13:116-129]

Avocado may help improve glycaemic control in individuals with T2D through the fruit’s bioactive compounds. In a previous animal study, for example, 5 weeks of supplementation with avocatin B—an avocado-derived lipid—resulted in better glucose tolerance, glucose utilization, and reduced insulin resistance in mice with diet-induced obesity. This effect was likely due to a decrease in the breakdown of fatty acids, but this was not tested directly nor was its application to human metabolism examined. [J Nat Prod 2018;81:818-824]

“Other evidence supports the overall macronutrient content of avocado as a plausible mediating mechanism, especially the high MUFA content. MUFA is thought to have a beneficial effect of dietary on insulin sensitivity via a conserved IRS-1/PI3 kinase insulin signalling pathway,” the investigators said. [Lipids 2010;45:1109-1116]

They called for intervention or feeding studies to provide more definitive evidence as to how and why avocado affects measures of glycaemia indicative of better glucose homeostasis, as well as how this can be harnessed for the management and, potentially, the prevention of T2D.