High habitual dietary α-linolenic acid intake is associated with decreased plasma soluble interleukin-6 receptor concentrations in male twins

Abstract

Background: a-Linolenic acid (ALA) is associated with a low risk of cardiovascular disease; however, the underlying mechanism is not completely known. Objective: The objective was to examine whether habitual dietary ALA intake is associated with plasma concentrations of inflammatory biomarkers after control for shared genetic and common environmental factors. Design: We cross-sectionally studied 353 middle-aged male twins. Habitual diet was assessed with the Willett food-frequency questionnaire. Fasting plasma concentrations of interleukin-6 (IL-6) and its soluble receptor (sIL-6R), high-sensitivity C-reactive protein (hsCRP), and tumor necrosis factor-a (TNF-a) were measured. Linear mixed-effect regression analysis was used to partition the overall association into within-and between-pair associations. Results: A 1-g increment in habitual dietary ALA intake was associated with 11.0% lower concentrations of sIL-6R (P = 0.004) but not of IL-6 (P = 0.31), TNF-a (P = 0.16), or hsCRP (P = 0.36) after adjustment for energy intake, nutritional factors, known cardiovascular disease risk factors, and medications. After further control for shared genetic and common environmental factors by comparison of brothers within a twin pair, a twin with a 1-g higher ALA intake was likely to have 10.9% (95% CI: 3.7%, 17.6%; P = 0.004) lower sIL-6R concentrations than his co-twin with a low intake, whereas ALA intake was not significantly associated with plasma concentrations of IL-6, TNF-a, or hsCRP. These results were validated by using 1000 bootstrap samples. Conclusions: Habitual dietary ALA intake is inversely associated with plasma sIL-6R concentrations independent of shared genetic and common environmental influences. Lowering sIL-6R may be a mechanism underlying the cardioprotective properties of habitual dietary ALA. This study was registered at clinicaltrials.gov as NCT00017836.Am J Clin Nutr 2010;92:177-85.

The Role of Soy in Vegetarian Diets

“…For example, a recently published cross-sectional study that included 353 male twins found that a one gram increment in habitual ALA intake was associated with an 11% decrease in plasma soluble interleukin-6 receptor concentrations, which by virtue of decreasing inflammation, could reduce CHD risk [76]. The reader is referred to the references for perspectives on whether vegetarians are at a disadvantage by not consuming DHA and EPA-containing fish [77,78].…”

Alpha-Linolenic Acid: Is It Essential to Cardiovascular Health?

“…Dai et al [20•] examined habitual ALA intake and plasma concentrations of inflammatory markers, including IL-6 and sIL-6R, in 353 middle-aged men in the United States who were recruited from a twin registry. ALA intake, assessed by the Willett questionnaire, ranged from 0.2 to 2 g/d, and was significantly inversely related to plasma sIL-6R independent of shared genetic factors and a wide range of potential confounders.…”

No Positive Influence of Ingesting Chia Seed Oil on Human Running Performance

“…Although studies are not consistent, long-term and high ALA intake has been associated with decreased risk of cardiovascular disease [ 5 , 6 , 7 , 8 , 26 ]. Inflammation is a pathophysiologic pathway for cardiovascular disease, and several studies support reduced systemic inflammation in groups with high dietary ALA intake [ 11 , 12 , 13 , 26 ]. A cross-sectional study of 353 middle-aged male twins showed that a 1-g increment in habitual dietary ALA intake was associated with 11% lower concentrations of the IL-6 soluble receptor (sIL-6R) [ 26 ].…”

“…Inflammation is a pathophysiologic pathway for cardiovascular disease, and several studies support reduced systemic inflammation in groups with high dietary ALA intake [ 11 , 12 , 13 , 26 ]. A cross-sectional study of 353 middle-aged male twins showed that a 1-g increment in habitual dietary ALA intake was associated with 11% lower concentrations of the IL-6 soluble receptor (sIL-6R) [ 26 ]. Cytokine production in cultured peripheral blood mononuclear cells (PBMCs) is decreased following high ALA diets in hypercholesterolemic subjects [ 27 ].…”