Abstract 17: One Avocado Per Day Lowers Plasma Oxidized-LDL and Increases Plasma Antioxidants in Overweight and Obese Adults
Background: Avocados are a nutrient dense source of monounsaturated fatty acids (MUFA) and also are high in antioxidants. A previous study has shown that avocados have additional LDL-C lowering effects beyond their MUFA content, especially on small, dense LDL particles, which are susceptible to oxidation in vivo. However, there is little information about the effects of avocados on oxidative stress.
Methods and Result: A randomized, cross-over, controlled feeding trial was conducted with 45 healthy, but overweight or obese participants with a baseline LDL-C in the 25-90th percentile. Three cholesterol-lowering diets (6-7% SFA) were fed (for 5 weeks each): a lower-fat diet (LF: 24% fat); two moderate fat diets (34% fat) that provided similar foods and were matched for macronutrients and fatty acids: the avocado diet (AV) included one fresh Hass avocado (136 g) per day whereas the moderate fat diet (MF) used high oleic acid oils mainly to match the fatty acid content of one avocado. Compared to the baseline, only the AV diet decreased oxLDL (-7.0 U/L, -8.8%, p=0.0004) whereas the LF (-1.6 U/L p=0.1) and the MF diets (-3.2 U/L, p=0.2) did not affect oxLDL significantly. Moreover, plasma oxLDL after consumption of the AV diet was significantly lower (p=0.05 and 0.03) than the MF and LF diets. HPLC analysis showed that only the AV diet increased plasma lutein by 68.7% from baseline (p<0.0001), and the increase in lutein by the AV diet was significantly greater than the increase by the MF (21.1%, p=0.7) and LF (37.6%, p=0.1) diets. Both MF and AV diets significantly increased plasma α-carotene (72.8% and 68.4%, p<0.01 for both) and β-carotene (15.4% and 12%, p<0.05 for both) from baseline. The LF diet did not change plasma antioxidant vitamins significantly, except for a decrease in γ-tocopherol (-7.8%, p=0.03). All three diets did not change plasma F2-isoprotane significantly from baseline. The change in oxLDL was significantly correlated with the change in small LDL-P (r=0.32, p=0.0002) and small, dense LDL-C (r=0.47, p<0.0001) by not large LDL-P (r=0.15, p=0.09) or large, buoyant LDL-C (r=-0.03, p=0.8).
Conclusion: Including one avocado per day in a heart-healthy diet lowers plasma oxidized LDL and lutein concentration; the benefits extend beyond their fatty acid content. The change in oxidized LDL by diet was correlated with a change in small LDL but not large LDL particles.
Author Disclosures: L. Wang: None. L. Tao: None. T.H. Stanley: None. J.A. Fleming: None. J.D. Lambert: None. P.M. Kris-Etherton: None.
- © 2015 by American Heart Association, Inc.