Positive Health Online

Abstract

JULIA and COLLEAGUES,  (1)Inserm (National Institute of Health and Medical Research), U557 Nutritional Epidemiology Unit, Bobigny, France evaluated the long-term associations between dietary intakes of PUFAs and elevated plasma C-reactive protein (CRP) and to investigate potential effect modification by vitamin E.

Background

Although n-3 (ω-3) polyunsaturated fatty acids (PUFAs) are considered anti-inflammatory components, the role of dietary n-6 PUFAs in inflammation remains controversial. Some mechanistic evidence suggests vitamin E as a potential effect modifier in the relationship between PUFAs and inflammation. Our objectives were to evaluate the long-term associations between dietary intakes of PUFAs and elevated plasma C-reactive protein (CRP) and to investigate potential effect modification by vitamin E.

Methodology

Individuals in the placebo group of the SU.VI.MAX trial who had available CRP measurements in 2007-2009 were included in the study (n = 843). Dietary intakes of n-3 PUFAs, n-6 PUFAs, and vitamin E were assessed in 1994-1996 with at least 6 dietary records. The logistic regression OR for elevated CRP (>3 mg/L) and 95% CI were estimated for individual PUFAs and for total n-3 and n-6 PUFA intakes. Models were adjusted for sociodemographical, lifestyle, anthropometric, and dietary variables. Interactions with vitamin E intakes were also assessed.

Results

Inverse associations were observed between intakes of total n-3 PUFAs [α-linolenic acid (ALA; 18:3n-3), ALA + eicosapentaenoic acid (EPA; 20:5n-3), EPA + docosapentaenoic acid (DPA; 22:5n-3), DPA + docosahexaenoic acid (DHA; 22:6n-3)] and n-6 PUFA [linoleic acid (18:2n-6) + arachidonic acid (20:4n-6)] and elevated CRP (OR for tertile 3 vs. tertile 1 of intake: 0.41; 95% CI: 0.21, 0.77; P-trend = 0.01; and OR 0.38; 95% CI: 0.21, 0.70; P-trend = 0.002, respectively). Stratification on vitamin E intakes showed that inverse associations between dietary n-3 and n-6 PUFA intakes and elevated CRP were substantial only in individuals with low intakes of vitamin E.

Conclusion

The authors’ results supported the contention that intakes of both n-3 and n-6 PUFAs are inversely associated with plasma CRP concentrations. Vitamin E is a potential effect modifier and should therefore be taken into account in such investigations. This trial was registered at clinicaltrials.gov as NCT00272428.

References

Julia C(1), Touvier M, Meunier N, Papet I, Galan P, Hercberg S, Kesse-Guyot E. Intakes of PUFAs were inversely associated with plasma C-reactive protein 12 years later in a middle-aged population with vitamin E intake as an effect modifier.  J Nutr. 143(11):1760-6. doi: 10.3945/jn.113.180943. Nov 2013. Epub Sep 11 2013.