The impact of avocado fruit on postprandial markers of cardio‐metabolic risk: An acute dose response study

Avocados are a distinctive fruit characterized by their nutrient‐rich content including monounsaturated fat (MUFA), fiber and a number of essential micronutrients and bioactive phytochemicals. The aim of the present study was to assess the acute effects of two intake levels of avocado compared to no avocado on postprandial indices of metabolic and vascular health including glucose, insulin, lipids, and flow‐mediated dilation (FMD) and biomarkers of inflammation and oxidative stress/damage. A single‐center, randomized, 3‐arm, controlled, 6‐h postprandial, crossover study was conducted in relatively healthy overweight/obese middle‐aged adults (n=31). Participants consumed a standardized Western‐style breakfast (640 kcal) containing 0 mg (Control), 68g (~ ½ Hass avocado, Half‐A) or 136 g (~ 1 Hass avocado, Whole‐A) on three separate occasions. Increasing the MUFA and fiber content of the meal by replacing calories from carbohydrate with calories from avocados decreased the postprandial glycemic and insulinemic responses to meals over 6 h, independent of dose, compared to the Control meal (both p<0.0001). FMD (% change) was significantly increased with avocado in the meals (treatments and treatment by time interaction, p<0.01 and p<0.005, respectively (percent Mean FMD ± SEM for Half‐A: baseline 5.2 ± 0.9%, 1‐h 9.0 ± 0.9% and 3‐h 11.5% ± 0.9%; Whole‐A: baseline 5.4 ± 0.9%, 1‐h 10.6 ± 0.9%, 3‐h 10.5 ± 0.9%; Control: baseline 5.6 ± 0.9%, 1‐h 5.0 ± 0.9%, 3‐h 7.4 ± 0.9%). Nuclear magnetic resonance (NMR) analyses of lipids/lipoprotein particles indicated modified lipoprotein metabolism with Whole‐A consumption vs Control. Briefly, lower concentrations of postprandial triglyceride rich lipoprotein particles after the Whole‐A compared to the Control meal (p=0.02) were evident. A trend for treatment differences in the metabolism of LDL and HDL particles were also apparent with indication of differences by race/ethnicity on some outcomes (p<0.05). No differences in the concentrations of oxidized LDL, MCP‐1, IL‐6 were observed over time or between meals, although TNF‐α tended to be lower after Whole‐A vs Control meal (p=0.07). The present study provides important insight regarding the acute metabolic and cardio‐vascular benefits of incorporating avocados into a meal. Avocado meals improved postprandial glucose, insulin and lipid profiles with concomitant improvements in vascular reactivity as measured by FMD in middle‐aged, overweight/obese adults. The data contribute to a growing body of evidence revealing the health benefits of avocados. Support or Funding Information Supported by Hass Avocado Board, Irvine, CA