Intake of n-6 and n-3 fatty acids and fish and risk of community-acquired pneumonia in US men.
BACKGROUND
Essential fatty acids modulate inflammation and glucose metabolism and may alter infection risk.


OBJECTIVE
We examined the association between intakes of n-6 and n-3 fatty acids and fish and the risk of community-acquired pneumonia.


METHODS
We prospectively evaluated 38,378 male US health professionals aged 44-79 y at the outset. We updated medical and lifestyle information biennially through questionnaires and diet every 4 y with the use of a validated food-frequency questionnaire. We excluded men who reported pneumonia, myocardial infarction, stroke, other heart disease, arterial surgery, cancer, or asthma before 1990 or those with incomplete dietary data. Community-acquired pneumonia was determined by blinded medical record review of chest radiographs.


RESULTS
During 10 y of follow-up, there were 441 new cases of nonfatal community-acquired pneumonia. Pneumonia risk was lower in men in the highest energy-adjusted quintiles of intake than in men in the lowest quintiles of intake of linoleic acid [multivariate relative risk (RR): 0.70; 95% CI: 0.51, 0.96; P for trend = 0.01] and alpha-linolenic acid (multivariate RR: 0.68; 95% CI: 0.50, 0.93; P for trend = 0.01). Pneumonia risk decreased 4% for every 1-g/d increase in linoleic acid intake (multivariate RR: 0.96; 95% CI: 0.93, 0.99). Pneumonia risk was reduced by 31% for every 1-g/d increase in alpha-linolenic acid intake (multivariate RR: 0.69; 95% CI: 0.51, 0.93). Intakes of eicosapentaenoic acid and docosahexaenoic acid were not significantly related to pneumonia risk.


CONCLUSIONS
Higher intakes of alpha-linolenic and linoleic acids and possibly of fish may reduce the risk of pneumonia.
Merchant
Anwar T
AT
Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. merchant@ccc.mcmaster.ca
Curhan
Gary C
GC
Rimm
Eric B
EB
Willett
Walter C
WC
Fawzi
Wafaie W
WW
D000328:Adult; D000368:Aged; D000818:Animals; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000209:etiology; D016001:Confidence Intervals; D004034:Diet Surveys; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D043371:Fatty Acids, Omega-6 / Q000008:administration & dosage*; D005399:Fishes; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008019:Life Style; D019787:Linoleic Acid / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011014:Pneumonia / Q000453:epidemiology* / Q000209:etiology; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D017962:alpha-Linolenic Acid / Q000008:administration & dosage
D004042:Dietary Fats, Unsaturated; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D017962:alpha-Linolenic Acid; D019787:Linoleic Acid