Dietary intervention with oil rich fish reduces platelet-monocyte aggregation in man.
BACKGROUND
Dietary intake of fish rich in omega-3 fatty acids is associated with a reduction in cardiovascular events. The mechanisms for this are uncertain and previous studies investigating effects on platelet function have produced inconsistent results. Platelet-monocyte aggregation is a sensitive marker of platelet activation and may contribute to the initiation and progression of atherothrombosis. This study assessed the effect of dietary intervention with oily fish on platelet-monocyte aggregation in healthy subjects.


METHODS
Fourteen subjects had their diet supplemented with 500 g of oil-rich fish per week for 4 weeks. A control group of 14 subjects received no dietary intervention over a 4-week period. Platelet-monocyte aggregates were assessed with flow cytometry.


RESULTS
Dietary intervention with fish led to an increase in omega-3 fatty acids in plasma phospholipids (14.2+/-3.4% versus 5.8+/-1.3%, P<0.001). In contrast to the control group, platelet-monocyte aggregates were reduced by 35% following dietary intervention with oily fish (16.0+/-9.0% versus 24.8+/-10.9%, P<0.01), and returned to basal levels 4 weeks after discontinuation of supplementation. There was an inverse correlation between platelet-monocyte aggregation and plasma omega-3 fatty acid concentrations (r=-0.421, P=0.006). There were no changes in the plasma markers of platelet activation, soluble P-selectin or soluble CD40 ligand.


CONCLUSIONS
We have demonstrated, for the first time, that dietary intervention with oil-rich fish reduces platelet-monocyte aggregation in man. Our results suggest that reduced platelet activation provides a potential mechanism through which fish oils confer their cardiovascular preventative benefits.
Din
Jehangir N
JN
Centre for Cardiovascular Sciences, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, United Kingdom. jehangirdin@hotmail.com
Harding
Scott A
SA
Valerio
Christopher J
CJ
Sarma
Jaydeep
J
Lyall
Karin
K
Riemersma
Rudolph A
RA
Newby
David E
DE
Flapan
Andrew D
AD
D000328:Adult; D050197:Atherosclerosis / Q000517:prevention & control*; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects*; D023201:CD40 Ligand / Q000097:blood; D002450:Cell Communication / Q000187:drug effects; D005227:Fatty Acids / Q000097:blood; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005395:Fish Oils / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D009000:Monocytes / Q000166:cytology / Q000187:drug effects*; D019007:P-Selectin / Q000097:blood; D010743:Phospholipids / Q000097:blood; D010974:Platelet Aggregation / Q000187:drug effects
D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D019007:P-Selectin; D010743:Phospholipids; D023201:CD40 Ligand