Higher dietary intake of alpha-linolenic acid is associated with lower insulin resistance in middle-aged Japanese.
OBJECTIVE
To investigate the associations between dietary intake of n-3 polyunsaturated fatty acids (plant-derived alpha-linolenic acid: ALA, and marine-derived eicosapentaenoic and docosahexaenoic acid: EPA+DHA) and insulin resistance (IR) in a lean population with high n-3 PUFA intake.


METHODS
We cross-sectionally studied 3383 Japanese local government workers aged 35-66 in 2002. IR was defined as the highest quartile of homeostasis model assessment, and nutrient intake was estimated from a diet history questionnaire. The odds ratios (ORs) of IR taking the lowest quartile of ALA or EPA+DHA intake as the reference were calculated by logistic regression analysis.


RESULTS
Mean age, body mass index (BMI), and dietary ALA, and median of dietary EPA+DHA were 47.9 years, 22.9 kg/m(2), and 1.90 g/day (0.88%E) and 0.77 g/day (0.36%E), respectively. The ORs of IR decreased across the quartiles of ALA intake (multivariate-adjusted OR for Q4 versus Q1=0.74, P for trend=0.01) and the association was observed only in subjects with a BMI of <25 kg/m(2) (P for interaction=0.033). However EPA+DHA showed no such associations consistently.


CONCLUSIONS
Higher ALA intake was significantly associated with a lower prevalence of IR in normal weight individuals of middle-aged Japanese men and women.
Muramatsu
Takashi
T
Department of Public Health/Health Information Dynamics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, Japan.
Yatsuya
Hiroshi
H
Toyoshima
Hideaki
H
Sasaki
Satoshi
S
Li
Yuanying
Y
Otsuka
Rei
R
Wada
Keiko
K
Hotta
Yo
Y
Mitsuhashi
Hirotsugu
H
Matsushita
Kunihiro
K
Murohara
Toyoaki
T
Tamakoshi
Koji
K
D000328:Adult; D000368:Aged; D015992:Body Mass Index; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D004034:Diet Surveys; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000494:pharmacology; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000494:pharmacology; D002149:Energy Intake / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015596:Nutrition Assessment; D015995:Prevalence; D017962:alpha-Linolenic Acid / Q000008:administration & dosage* / Q000494:pharmacology
D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids; D015118:Eicosapentaenoic Acid