The relation of diet with PAF and its metabolic enzymes in healthy volunteers

Platelet-activating factor (PAF), a potent inflammatory mediator, is implicated in atherosclerosis. Its key biosynthetic enzymes are lyso-PAF acetyltransferases (lyso-PAF-AT), responsible for PAF synthesis through the remodeling route and a specific CDP-choline:1-alkyl-2-acetyl-sn-glycerol cholinephosphotransferase (PAF-CPT), responsible for its de novo biosynthesis. PAF acetylhydrolase (PAF-AH) and its extracellular isoform lipoprotein-associated phospholipase A₂ catabolize PAF. The impact of diet on PAF metabolism is ill-defined. The aim was to investigate associations between PAF, its enzymes and dietary factors.

One-hundred and six (n = 106) healthy volunteers were recruited. Food-frequency questionnaires, dietary recalls, lifestyle and biochemical variables were collected. Food groups, macronutrient intake, a priori (MedDietScore) and a posteriori defined food patterns with PCA analysis, dietary antioxidant capacity (DAC), glycemic index (GI) and glycemic load were assessed.

PAF was inversely correlated with antioxidant-rich foods (herbal drinks and coffee), the DAC as well as a dietary pattern characterized by legumes, vegetables, poultry and fish (all Ps < 0.05). PAF was positively correlated to % fat intake. Lyso-PAF-AT was also negatively associated with healthy patterns (fruits, nuts and herbal drinks, and a pattern rich in olive oil and whole-wheat products), as well as the DAC and % monounsaturated fatty acids. PAF-CPT was negatively associated with GI and coffee intake and positively with dietary cholesterol. PAF-AH was negatively associated with coffee and positively associated with alcohol consumption (all Ps < 0.05).

In conclusion, the DAC and healthy dietary patterns were inversely associated with PAF or its biosynthetic enzymes, suggesting potential new mechanisms of the diet-disease associations.