Elsevier

Nutrition Research

Volume 28, Issue 5, May 2008, Pages 309-314
Nutrition Research

Research Article
Total n-3 polyunsaturated fatty acid intake is inversely associated with serum C-reactive protein in young Japanese women

https://doi.org/10.1016/j.nutres.2008.03.008Get rights and content

Abstract

Little is known about the relation of dietary factors to circulating C-reactive protein (CRP) concentrations in young adults and non-Western populations. We cross-sectionally examined associations between dietary intake and serum CRP concentrations in young Japanese women. The subjects were 443 female Japanese dietetic students aged 18 to 22 years. Dietary intake was assessed with a validated, self-administered, comprehensive, diet history questionnaire. Serum CRP concentrations were measured by highly sensitive nephelometry. The prevalence of elevated CRP (≥1 mg/L) was 5.6%. After adjustment for possible confounding factors including body mass index, a significant inverse association was seen between total n-3 polyunsaturated fatty acid intake and elevated CRP. The multivariate adjusted odds ratios of elevated CRP for women with intake below and above the median (1.1% of energy) were 1.00 and 0.33 (95% confidence interval, 0.13-0.82; P = .02), respectively. Intake of eicosapentaenoic acid + docosahexaenoic acid and α-linolenic acid was not associated with elevated CRP concentrations (P = .62 and P = .27, respectively). Vitamin C intake was independently inversely associated with elevated CRP, although the association was nonsignificant (P = .10). No clear associations were observed for other dietary factors examined including total fat, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, total dietary fiber, soluble dietary fiber, insoluble dietary fiber, and magnesium; fruits, vegetables, and fish and shellfish; and dietary glycemic load (P = .27 to P = .99). In conclusion, total n-3 polyunsaturated fatty acid intake showed an independent inverse association with elevated serum CRP concentration in a group of young Japanese women.

Introduction

C-reactive protein (CRP) is a sensitive marker of inflammation that is independently and directly associated with cardiovascular disease [1], type 2 diabetes [2], and metabolic syndrome [3]. Identification of modifiable lifestyle factors that influence circulating CRP concentrations (eg, dietary habits) is thus vitally important from a prevention perspective. Nutrients suggested to be associated with CRP concentration in epidemiologic studies include fat and several fatty acids [4], [5], [6], [7], [8], dietary fiber [4], [9], [10], magnesium [11], [12], and vitamin C [13], [14]. At the food level, associations have been reported for fruits [14], [15], [16], vegetables [14], [15], [16], and fish [17]. An association with dietary glycemic load (a measure of carbohydrate quality and quantity) has also been suggested [18]. However, almost all these studies have been conducted in middle-aged and elderly populations in Western countries [4], [5], [6], [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], and evidence from non-Western countries [7], [8] and young adult populations [7] is extremely limited.

Here, we conducted a cross-sectional study of associations between selected dietary factors, that is, intake of total fat, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), total n-3 PUFA, eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA), α-linolenic acid (ALA), total dietary fiber, soluble dietary fiber, insoluble dietary fiber, magnesium, and vitamin C; intake of fruits, vegetables, and fish and shellfish; and dietary glycemic load, with serum CRP concentration in a group of young Japanese women.

Research among Japanese populations is important because the differences in dietary habits between Japanese and Western populations (particularly, higher intake of fish and, hence, n-3 PUFA in Japanese than in Western populations [19], [20]) hamper the extrapolation of findings in Western countries to Japanese. Research among young adult populations is also important from the standpoint of prevention. We hypothesized that dietary habits (particularly n-3 PUFA intake) influence serum CRP concentrations in young Japanese women.

Section snippets

Subjects

The present study was based on a multicenter survey conducted from February to March 2006 among female dietetic students from 10 institutions in Japan. All measurements at each institution were conducted according to the survey protocol. Staff at each institution provided an outline of the survey to potential subjects. Those responding positively were then provided detailed written and oral explanations of the general purpose and procedure of the survey. The protocol of the study was approved

Results

Subject characteristics are shown in Table 1. Mean ± SD serum CRP concentration was 0.302 ± 0.727 mg/L, with a range of 0.025 to 7.100 mg/L. The prevalence of elevated CRP concentration was 5.6%. Overall, subjects were characterized by a relatively low BMI (mean ± SD, 21.3 ± 2.9 kg/m2) and a low smoking rate (3.4%). About three fifths (59.1%) of subjects were alcohol nondrinkers, and dietary supplements were used by about one fifth (19.4%) of subjects. Mean ± SD dietary intake was 1.1 ± 0.3% of

Discussion

In this study of young Japanese women, we found that a higher intake of total n-3 PUFA was associated with a lower prevalence of elevated CRP concentrations, independently of potential confounding factors, including BMI. Similar inverse relations have been observed not only in middle-aged American women [6] but also in elderly Japanese men and women [8]. The inverse relation between total n-3 PUFA intake and circulating CRP is biologically reasonable, given that n-3 PUFA possesses

Acknowledgment

This study was supported by grants from the Ministry of Health, Labor, and Welfare of Japan.

References (34)

  • A. Zampelas et al.

    Fish consumption among healthy adults is associated with decreased levels of inflammatory markers related to cardiovascular disease: the ATTICA study

    J Am Coll Cardiol

    (2005)
  • S. Liu et al.

    Relation between a diet with a high glycemic load and plasma concentrations of high-sensitivity C-reactive protein in middle-aged women

    Am J Clin Nutr

    (2002)
  • K. Murakami et al.

    Dietary glycemic index and load in relation to metabolic risk factors in Japanese female farmers with traditional dietary habits

    Am J Clin Nutr

    (2006)
  • M.J. James et al.

    Dietary polyunsaturated fatty acids and inflammatory mediator production

    Am J Clin Nutr

    (2000)
  • P.M. Ridker et al.

    C-reactive protein and other markers of inflammation in the prediction of cardiovascular disease in women

    N Engl J Med

    (2000)
  • A.D. Pradhan et al.

    C-reactive protein, interleukin 6, and risk of developing type 2 diabetes mellitus

    JAMA

    (2001)
  • M.K. Rutter et al.

    C-reactive protein, the metabolic syndrome, and prediction of cardiovascular events in the Framingham Offspring Study

    Circulation

    (2004)
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