Alpha-Linolenic and Linoleic Fatty Acids in the Vegan Diet: Do They Require Dietary Reference Intake/Adequate Intake Special Consideration?

Burns-Whitmore Burns-Whitmore,Parker Parker,San Pablo San Pablo,Heskey Heskey,Froyen Froyen

doi:10.3390/nu11102365

Burns-Whitmore Burns-Whitmore, Parker Parker + Show 3 more

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https://doi.org/10.3390/nu11102365

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Abstract

Good sources of the long-chain n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) include cold-water fish and seafood; however, vegan diets (VGNs) do not include animal-origin foods. Typically, US omnivores obtain enough dietary EPA and DHA, but unless VGNs consume algal n-3 supplements, they rely on endogenous production of long-chain fatty acids. VGN diets have several possible concerns: (1) VGNs have high intakes of linoleic acid (LA) as compared to omnivore/non-vegetarian diets. (2) High intakes of LA competitively interfere with the endogenous conversion of alpha-linolenic acid (ALA) to EPA and DHA. (3) High somatic levels of LA/low ALA indicate a decreased ALA conversion to EPA and DHA. (4) Some, not all VGNs meet the Dietary Reference Intake Adequate Intake (DRI-AI) for dietary ALA and (5) VGN diets are high in fiber, which possibly interferes with fat absorption. Consequently, health professionals and Registered Dietitians/Registered Dietitian Nutritionists working with VGNs need specific essential fatty acid diet guidelines. The purpose of this review was: (1) to suggest that VGNs have a DRI-AI Special Consideration requirement for ALA and LA based on VGN dietary and biochemical indicators of status and (2) to provide suggestions to ensure that VGNs receive adequate intakes of LA and ALA.

Highlights

The polyunsaturated n-6 and n-3 fatty acids are essential for a variety of functions in the body, including the synthesis of prostaglandins, leukotrienes, cellular membranes, phospholipids, retinal photoreceptors, cerebral gray matter, testes, and sperm
The present Dietary Reference Intakes (DRIs) Adequate Intake (AI) for essential fatty acids is intended for general healthy populations, and does not take into account groups with specific dietary needs/requirements
We suggest that adult vegan diets (VGNs) have separate AIs for linoleic acid (LA) and alpha-linolenic acid (ALA) than omnivores and utilize recommendations of between 2.2–4.4 g/g of ALA d

Summary

Introduction

The polyunsaturated n-6 and n-3 fatty acids are essential for a variety of functions in the body, including the synthesis of prostaglandins, leukotrienes, cellular membranes, phospholipids, retinal photoreceptors (vision), cerebral gray matter (brain tissue), testes, and sperm. Arachidonic acids (20:4n-6; AA) are classified as n-6 fatty acids, and α-linolenic (18:3n-3; ALA), eicosapentaenoic (20:5n-3; EPA) and docosahexaenoic acids (22:6n-3; DHA) are n-3 fatty acids [1] Of these fatty acids, LA and ALA are considered essential and must be provided by the diet. The Dietary Reference Intakes (DRIs) are “nutrient reference values” developed by the Institute of Medicine of The National Academies. They are intended to serve as a guide for good nutrition and provide the scientific basis for the development of food guidelines in both the United States and Canada, and these nutrient reference values are specified on the basis of age, gender and lifestage groups” [2]. New research or discoveries of physiological factors, inborn errors of metabolism, health

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