Linoleic Acid Associated with Lower Overall Mortality Risk

by | Jul 20, 2018 | 2018, Alternative Therapies, Cardiovascular Health, Polyunsaturated

Written by Angeline A. De Leon, Staff Writer. Study found that higher serum concentrations of linoleic acid, the major omega-6 polyunsaturated fatty acid, are inversely associated with the risk of death due to disease, CVD, and non-CVD or non-cancer causes while arachidonic acid demonstrated a weaker inverse association.

cardiovascular healthThe primary goal of many dietary fat modification programs has involved reducing risk of cardiovascular disease (CVD), typically through partial replacement of saturated fat with polyunsaturated fatty acids (PUFAs) like omega-3 and omega-6 1. Common sources of omega-6 PUFAs include flaxseed, hempseed, and grapeseed oil, as well as pumpkin and sunflower seeds. Dietary health guidelines have advised substituting saturated fat sources like butter with vegetable oils or margarines high in omega-6 PUFAs 2 however, the basis for such claims has recently come under scrutiny. While research on the cardioprotective health benefits of omega-6 PUFAs has garnered significant attention among the general public, increased dietary intake has failed to demonstrate any clear, significant effect on CVD incidence 3, and much less is known about its association with non-CVD endpoints. In fact, some studies have raised concerns regarding the impact of omega-6 on disease risk for other conditions 4. Because certain PUFAs like linoleic acid (LA) function as substrates for proinflammatory mediators, in some studies, increased intake has actually been linked to higher risk of other chronic diseases such as cancer and diabetes 5,6. To elucidate the prospective association of serum omega-6 PUFAs with the risk of death from other causes, not just CVD-related mortality, researchers at the University of Eastern Finland investigated how omega-6 PUFAS, including LA, gamma-linolenic acid (GLA), dihomo-gamma-linolenic acid (DGLA), and arachidonic acid (AA) relate to mortality risk.

A total of 2480 males (aged 42-60 years at baseline), 1019 of whom had a history of CVD, cancer, or diabetes, and 1461 of whom did not report a history of disease, were evaluated in a prospective, population-based study conducted in Finland. At baseline, fasting venous blood samples were collected and serum fatty acids were measured from stored samples. Deaths were determined using computer linkage to the national cause of death registry in Finland and coded according to the International Classification of Diseases codes.

Mean follow-up time was 22.4 years, during which time 1143 deaths due to disease (575 CVD deaths, 317 cancer deaths, and 251 other-cause deaths) were reported. When comparing the highest LA quintile with the lowest LA quintile, multivariable-adjusted analyses indicated that higher serum LA concentration was associated with lower risk of death from any cause (Hazard Ratio = 0.57, 95% Confidence Interval: 0.46 to 0.71, p-trend < 0.001), deaths due to CVD (HR = 0.54, 95% CI: 0.40 to 0.74, p-trend < 0.001), and non-CVD or non-cancer causes (HR = 0.48, 95% CI: 0.30 to 0.76, p-trend = 0.001). Similarly, although to a weaker degree, higher serum AA was associated with lower risk of death from any cause (HR = 0.80, 95% CI: 0.65 to 0.98, p-trend = 0.01) and deaths due to CVD (HR = 0.80, 95% CI: 0.60 to 1.06, p-trend = 0.009), and showed a trend toward lower risk of non-CVD or non-cancer death (p-trend = 0.002). Each 1-standard deviation increase in serum LA was associated with a 16% lower risk of death from any disease (HR = 0.84) and a 14% lower risk of CVD death (HR = 0.86). Each 1-standard deviation increase in serum AA was associated with an 8% lower risk of death from any disease (HR = 0.92) and a 5% lower risk of CVD death (HR = 0.95). Serum GLA and DGLA were not associated with risk of death.

General findings indicate an inverse association between higher serum concentrations of the major omega-6 PUFA LA and risk of death due to disease, CVD, and non-CVD or non-cancer causes. Results suggest a favorable overall impact of higher LA intake on health, with minimal concern for adverse risk. Findings regarding serum AA, as well as the other omega-6 PUFAs, warrant further study, ideally within a mixed gender study sample.

Source: Virtanen JK, Wu JHY, Voutilainen S, et al. Serum n-6 polyunsaturated fatty acids and risk of death: the Kuopio Ischaemic Heart Disease Risk Factor Study. Am J Clin Nutr. 2018; 107: 427-435. DOI: 10.1093/ajcn/nqx063.

© 2018 American Society for Nutrition. All rights reserved.

 Posted July 20, 2018.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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