Dietary linolenic acid is inversely associated with plasma triacylglycerol: the National Heart, Lung, and Blood Institute Family Heart Study
Dietary linolenic acid is inversely associated with plasma triacylglycerol: the National Heart, Lung, and Blood Institute Family Heart Study
Year: 2003
Authors: Djouss�, L. Hunt, S.C. Arnett, D.K. Province, M.A. Eckfeldt, J.H. Ellison, R.C.
Publication Name: Am. J. Clin. Nutr.
Publication Details: Volume 78; Pages 1098 – 1102.
Abstract:
Dietary intake of linolenic acid is associated with a decreased risk of cardiovascular disease mortality. However, the mechanisms by which dietary linolenic acid affects cardiovascular disease risk are not clearly understood. We examined the association between dietary linolenic acid and plasma triacylglycerol concentrations. In a cross-sectional design, we studied 4440 white subjects (2036 men and 2404 women) aged 25�93 y who participated in the National Heart, Lung, and Blood Institute Family Heart Study. We used generalized linear models to estimate adjusted mean triacylglycerol concentrations according to categories of total dietary linolenic acid (α- and ƴ-linolenic acid) intake. The mean dietary linolenic acid intakes were 0.81 and 0.69 g/d for the men and the women, respectively. High consumption of dietary linolenic acid was associated with young age; high intakes of energy, fat, carbohydrates, fruit, vegetables, and fish; low HDL cholesterol; current smoking; and frequent consumption of creamy salad dressing. High consumption of dietary linolenic acid was also associated with low plasma triacylglycerol concentrations. From the lowest to the highest quintile of linolenic acid intake, the multivariate-adjusted mean triacylglycerol concentrations were 1.75 (95% CI:1.65, 1.85), 1.74 (1.66, 1.82), 1.69 (1.61, 1.77), 1.66( 1.58, 1.74), and 1.54 (1.44, 1.64) mmol/L, respectively (P for linear trend= 0.007). When linolenic acid was used as a continuous variable, the corresponding regression coefficient was -0.2811 (-0.4922, -0.07001). Consumption of total linolenic acid is inversely related to plasma triacylglycerol concentrations in both white men and white women. This suggests a pathway by which dietary linolenic acid might reduce cardiovascular disease risk. (Author�s abstract)
A high consumption of ALA is associated with a low incidence of CAD and cardiovascular disease mortality. The reported association between dietary linolenic acid and triacylglycerol has been inconsistent. In this study, data collected from 4440 white participants in the National Heart, Lung, and Blood Institute (NHLBI) Family Heart Study was used to assess whether dietary consumption of total linolenic acid (α- and ƴ-linolenic acid) is associated with triacylglycerol concentrations in men and women.
A high consumption of ALA is associated with a low incidence of CAD and cardiovascular disease mortality. The reported association between dietary linolenic acid and triacylglycerol has been inconsistent. In this study, data collected from 4440 white participants in the National Heart, Lung, and Blood Institute (NHLBI) Family Heart Study was used to assess whether dietary consumption of total linolenic acid (α- and ƴ-linolenic acid) is associated with triacylglycerol concentrations in men and women.
DISCUSSION
Plasma triacylglycerol has often been found to be a determinant of atherosclerosis (29) and CAD (30, 31). Although fish-oil intake has been repeatedly shown to reduce plasma triacylglycerol concentrations (6, 8, 32), data remain inconsistent on the effects of linolenic acid on plasma triacylglycerol. In this cross-sectional study, we found that dietary linolenic acid was inversely associated with plasma triacylglycerol in both men and women and that this association was independent of fish consumption. The men and the women in the highest quintile of linolenic acid intake had triacylglycerol concentrations that were 26.0% and 14.6% lower, respectively, than those in the men and the women in the lowest quintile of linolenic acid intake. A limited number of studies have reported an inverse association between dietary linolenic acid intake and plasma triacylglycerol concentration. And some studies have reported no associations. The heterogeneity of study participants across studies, the wide range of amounts of ALA consumed, differences in the duration of intervention (from a few weeks to a few years), residual confounding, and inadequate power could partially account for the differences in study findings. In this study, large numbers of men and women and a wide range of covariates to control residual confounding were incorporated. In addition, the usual dietary intake of linolenic acid over the previous year was estimated. The results indicates that dietary linolenic acid intakes (range: 0.13�3.48 g/d) are inversely related to plasma triacylglycerol concentrations in white men and women. If confirmed by other studies, this finding should be explored as an additional dietary approach to lower elevated triacylglycerol. (Editor�s comments)
Plasma triacylglycerol has often been found to be a determinant of atherosclerosis (29) and CAD (30, 31). Although fish-oil intake has been repeatedly shown to reduce plasma triacylglycerol concentrations (6, 8, 32), data remain inconsistent on the effects of linolenic acid on plasma triacylglycerol. In this cross-sectional study, we found that dietary linolenic acid was inversely associated with plasma triacylglycerol in both men and women and that this association was independent of fish consumption. The men and the women in the highest quintile of linolenic acid intake had triacylglycerol concentrations that were 26.0% and 14.6% lower, respectively, than those in the men and the women in the lowest quintile of linolenic acid intake. A limited number of studies have reported an inverse association between dietary linolenic acid intake and plasma triacylglycerol concentration. And some studies have reported no associations. The heterogeneity of study participants across studies, the wide range of amounts of ALA consumed, differences in the duration of intervention (from a few weeks to a few years), residual confounding, and inadequate power could partially account for the differences in study findings. In this study, large numbers of men and women and a wide range of covariates to control residual confounding were incorporated. In addition, the usual dietary intake of linolenic acid over the previous year was estimated. The results indicates that dietary linolenic acid intakes (range: 0.13�3.48 g/d) are inversely related to plasma triacylglycerol concentrations in white men and women. If confirmed by other studies, this finding should be explored as an additional dietary approach to lower elevated triacylglycerol. (Editor�s comments)
