For adults with overweight and obesity, a heart-healthy diet that includes 1 avocado per day can decrease circulating oxidized low-density lipoprotein (LDL) concentrations, according to study results published in The Journal of Nutrition.
The results indicated that this effect was associated with a reduction in small dense LDL particles, which are associated with an increased risk for cardiovascular disease.
The study included participants aged 21 to 70 years with overweight or obesity and elevated LDL cholesterol (in the 25th-90th percentile for sex). Participants adhered to 3 cholesterol-lowering diets (5 weeks each) in random sequences. The diets included a lower-fat diet (24% calories from fat [7% saturated fatty acids, 11% monounsaturated fatty acids, 6% polyunsaturated fatty acids]) and 2 moderate-fat diets (34% calories from fat [6% saturated fatty acids, 17% monounsaturated fatty acids, 9% polyunsaturated fatty acids]). The first moderate-fat diet was an avocado diet, which included 1 Hass avocado (approximately 136 g) per day, and the second moderate-fat diet used high oleic acid oils to match the fatty acid profile of 1 avocado. The researchers used a general linear mixed regression model to analyze treatment effects.
Compared with baseline, participants who adhered to the avocado diet had significantly decreased circulating oxidized LDL (-7.0 U/L; -8.8%; P =.0004) and increased plasma lutein concentration (19.6 nmol/L; 68.7%; P <.0001). Compared with the moderate- and lower-fat diets, the reduction in oxidized LDL was significantly greater with the avocado diet (P ≤.05).
The results indicated that the change in oxidized LDL from the avocado diet was significantly correlated with changes in small dense LDL particles and cholesterol (r =0.32 [P =.0002] and 0.47 [P <.0001], respectively). However, reductions in oxidized LDL were not linked to any change in large buoyant LDL particles.
The researchers noted that their study was limited by the relatively short duration of the diet interventions.
“Avocados have a unique nutrient and bioactive profile that appears to play an important role in reducing LDL oxidation, hence decreasing LDL atherogenicity,” the researchers wrote.
Wang L, Tao L, Hao L, et al. A moderate-fat diet with one avocado per day increases plasma antioxidants and decreases the oxidation of small, dense LDL in adults with overweight and obesity: a randomized controlled trial [published online October 14, 2019]. J Nutr. doi:10.1093/jn/nxz231