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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #240714
Title: English walnuts (Juglans regia L.) protect endogenous antioxidants in humans

Author
item MCKAY, DIANE - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item CHEN, C-Y (OLIVER) - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item YEUM, KYUNG-JIN - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item CORREA, CAMILLA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University
item BLUMBERG, JEFFREY - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2009
Publication Date: 4/18/2009
Citation: Mckay, D.L., Chen, C., Yeum, K., Correa, C.R., Blumberg, J.B. 2009. English walnuts (Juglans regia L.) protect endogenous antioxidants in humans. Journal of Federation of American Societies for Experimental Biology. Abstract No. 718.10.

Interpretive Summary:

Technical Abstract: Ellagic acid monomers, polymeric tannins and related phenolic compounds isolated from English walnuts (Juglans regia L.) have been reported to inhibit LDL oxidation ex vivo and decrease biomarkers of oxidative stress in animal models. To determine whether dietary and endogenous antioxidants are preserved following walnut consumption in humans, we conducted a pilot study in 3 healthy adults. Subjects followed a low polyphenol diet for 2 d prior to the intervention. Fasting blood was then collected at baseline (0 h) and 2 h after consuming a single dose (45 g) of walnuts (WC). Lipophilic free radical initiators were added ex vivo, +/- 10 uM GAE methanolic walnut extract (WE). The oxidizability of lipid and aqueous plasma components were measured over 4 h and results expressed as percent area under the time course curve. WE protected alpha-tocopherol against oxidation at 0 h (P=0.045), but at 2 h the in vitro effect of WE was modest due to a contributing protective action by WC (P=0.021). At 2 h WE protected beta-carotene > WC alone (P=0.039). However, the interactive effect of WC + WE was > WE alone at 0 h (P=0.026). At 2 h, WC + WE also protected lycopene > WE alone at 0 h (P=0.032). No changes in plasma antioxidant levels were observed at 2 h. These data suggest that walnuts may protect against oxidative damage in human plasma by preserving endogenous antioxidant defenses. (Supported by USDA and California Walnut Commission)