Impact of α-Linolenic Acid, the Vegetable ω-3 Fatty Acid, on Cardiovascular Disease and Cognition

Abstract

Given the evidence of the health benefits of plant-based diets and long-chain n-3 fatty acids, there is keen interest in better understanding the role of alpha-linolenic acid (ALA), a plant-derived n-3 fatty acid, on cardiometabolic diseases and cognition. There is increasing evidence for ALA largely based on its major food sources (i.e., walnuts and flaxseed); however, this lags behind our understanding of long-chain n-3 fatty acids. Meta-analyses of observational studies have shown that increasing dietary ALA is associated with a 10% lower risk of total cardiovascular disease and a 20% reduced risk of fatal coronary heart disease. Three randomized controlled trials (AlphaOmega trial, Prevención con Dieta Mediterránea [PREDIMED] trial, and Lyon Diet Heart Study) all showed benefits of diets high in ALA on cardiovascular-related outcomes, but the AlphaOmega trial, designed to specifically evaluate ALA effects, only showed a trend for benefit. Randomized controlled trials have shown that dietary ALA reduced total cholesterol, low-density-lipoprotein cholesterol, triglycerides, and blood pressure, and epidemiological studies and some trials also have shown an anti-inflammatory effect of ALA; which collectively account for, in part, the cardiovascular benefits of ALA. A meta-analysis reported a trend toward diabetes risk reduction with both dietary and biomarker ALA. For metabolic syndrome and obesity, the evidence for ALA benefits is inconclusive. The role of ALA in cognition is in the early stages but shows promising evidence of counteracting cognitive impairment. Much has been learned about the health benefits of ALA and with additional research we will be better positioned to make strong evidence-based dietary recommendations for the reduction of many chronic diseases.

α‐linolenic acid interconversion is sufficient as a source of longer chain ω‐3 polyunsaturated fatty acids in humans: An opinion

“…Compared with the findings of epidemiological studies, the effect of αLNA supplementation on cardiovascular disease outcomes show relatively modest benefits (Sala‐Vila et al, 2022). Typical habitual intakes of αLNA, at least in high income countries, are approximately 0.5–2.3 g/ day (Baker et al, 2016) which is similar to the suggested optimal αLNA intake to ameliorate risk of cardiovascular disease of 2 g/day (de Lorgeril & Salen, 2004).…”

Impact of Nut Consumption on Cognition across the Lifespan

“…The omega-3 PUFA ALA, which is particularly abundant in walnuts, has been associated with cognitive function in older people [ 31 ]. However, it has been scarcely studied at younger ages.…”

Associations of α-linolenic acid dietary intake with very short sleep duration in adults

“…Many of these studies reported significant improvements in sleep quality ( 35 ). Fourth, poor sleep is related to inflammation ( 36 , 37 ), and ALA can be used as an effective anti-inflammatory agent ( 38 – 40 ). Fifth, 5-hydroxytryptamine (5-HT) receptor 1A and 5-HT receptor 2A levels were enhanced by ALA-rich diets ( 41 ).…”