Acute consumption of walnuts decreases CRP levels in healthy individuals, with high CRP

Abstract

Elevated C‐reactive protein increases risk for diabetes, hypertension and CVD. Dietary fatty acids, nutrients and bioactives, including antioxidants, modulate many risk factors for CVD, chronically and acutely. Walnuts are a rich source of antioxidants, unsaturated fats, and bioactives. In a randomized, cross‐over postprandial study, we evaluated the acute effects of whole walnuts (85 g) vs. walnut components (skins: 5.6 g; nut meat: 34 g; oil: 51 g) on CRP in healthy adults with moderate hypercholesterolemia. Blood samples were taken at fasting, and 0.5, 1, 2, 4, and 6 hr post meal. Fifteen participants completed the study (mean (SD) age: 49.8 (8.7) yrs; BMI: 29.3 (3.6) kg/m^2;). Four, five and six participants had low (<3 mg/L), normal (1‐3 mg/L) and high (>3 mg/L) fasting CRP concentrations, respectively. Whole walnut consumption reduced CRP at 1 hr (mean ?: ‐1.1 ± 0.7 mg/L, P=.012) in those who had high CRP, compared to an increase in those with low CRP (mean ?: +1.3 ± 0.6 mg/L). CRP also decreased at 1 hr following nut meat consumption in those with high (‐1.1 ± 0.3 mg/L, P=.040) vs. low CRP. Sustained reductions in CRP at 2, 4 and 6 hr also were found in those who had high vs. normal and low CRP levels (all P=0.005). There were no effects of walnut skins or oil on CRP. Consumption of whole walnuts and walnut meat decreases the postprandial inflammatory response in individuals with elevated CRP, which may reduce risk for CVD.