Dietary fat and plasma total homocysteine concentrations in 2 adult age groups: the Hordaland Homocysteine Study.
BACKGROUND
The intake of n-3 (formerly called omega-3) fatty acids (FAs) may be inversely associated with plasma total homocysteine (tHcy) concentrations, but the epidemiologic data are sparse.


OBJECTIVE
We examined the association between dietary fat and tHcy in a Norwegian population.


METHODS
A cross-sectional, population-based study of 5917 subjects in 2 age groups (47-49 and 71-74 y old) was conducted with the use of food-frequency questionnaires and measurement of plasma tHcy concentrations.


RESULTS
The intake of saturated FAs (SFAs) was positively and significantly (P for trend < 0.001) associated with tHcy concentrations; the difference in plasma tHcy concentrations between the highest and lowest quartiles of SFAs was 8.8%. The intake of marine very-long-chain n-3 FAs was inversely associated with tHcy concentrations; the difference in plasma tHcy concentrations between the lowest and the highest quartiles was -5.0% (P for trend < 0.001). Intakes of total and monounsaturated fat also were positively associated with plasma tHcy concentrations (P for trend < 0.001 and < 0.005, respectively), whereas the intake of polyunsaturated fat was positively associated with tHcy concentrations only in the younger subjects (P for trend = 0.03). The associations were weakened by additional adjustment for B vitamin intake but remained significant for SFA intake (P < 0.001). When stratified for total B vitamin intake, the inverse association between tHcy concentrations and very-long-chain n-3 FAs was significant only in the highest quartile of B vitamin intake (P for trend = 0.001), regardless of supplement use.


CONCLUSIONS
High intakes of SFAs are associated with high plasma concentrations of tHcy. The inverse association between dietary intakes of very-long-chain n-3 FAs and plasma tHcy concentrations is apparent only at high B vitamin intakes.
Berstad
Paula
P
Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Norway. p.m.berstad@medisin.uio.no
Konstantinova
Svetlana V
SV
Refsum
Helga
H
Nurk
Eha
E
Vollset
Stein Emil
SE
Tell
Grethe S
GS
Ueland
Per M
PM
Drevon
Christian A
CA
Ursin
Giske
G
D000368:Aged; D003430:Cross-Sectional Studies; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage*; D005227:Fatty Acids / Q000008:administration & dosage*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires; D014803:Vitamin B Complex / Q000008:administration & dosage
D004041:Dietary Fats; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D006710:Homocysteine; D014803:Vitamin B Complex