Dietary Long Chain n-3 PUFA Intake and Cardiovascular Health In Vegetarians and Vegans 
Wendy Hall, King’s College London 
London, United Kingdom

Vegans (VG) have a diet naturally devoid of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and dietary intakes in vegetarians (VGN) are very low on average (~0.02 g/d), which is associated with low EPA+DHA tissue status (1). Long chain (LC) n-3 PUFA levels do not seem to decline over longer durations in VG and VGN suggesting that a basal rate of conversion from alpha-linolenic acid to EPA is maintained (2). VG and VGN diets are also low in saturated fatty acids and rich in fibre and phytochemicals, and VG/VGN populations have lower LDL cholesterol concentrations, blood pressure and BMI than omnivores. As might be expected, many population studies have observed lower rates of coronary heart disease (CHD) in VG and VGN, but recent evidence from 2 combined population cohorts reported similar rates of all-cause mortality and no clear differences between VG and regular meat-eaters, fish-eaters and VGN in mortality from CHD (3). LC n-3 PUFA, especially DHA, is rapidly incorporated into phospholipids of cell membranes, including those of cardiomyocytes and neural tissue, thereby influencing membrane properties, membrane protein activity, and modulating the initiation and resolution of acute inflammatory responses. Fish oil consumption reduces heart rate in humans (4) and reduces pacemaker activity in sinoatrial node cells in animals, and may increase heart rate variability, an independent predictor of coronary events (5). Our recent research has shown that VG have increased ambulatory heart rates and lower heart rate variability during waking hours compared to omnivores suggesting that beneficial metabolic effects of VG diets might be offset by a reduction in the capacity of the heart to respond to fluctuating physiological demands. Alternative sources of LC n-3 PUFA, such as marine microalgae, may augment cardiovascular health in VG and VGN.

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(2) Rosell MS et al. (2005) Am J Clin Nutr 82, 327-334.
(3) Appleby PN et al. (2016) Am J Clin Nutr 103, 218-230.
(4) Mozaffarian D et al. (2005) Circulation 112, 1945-1952.
(5) Christensen JH et al. (2011) Frontiers in Physiology 2, 84.