Diet, Plasma, Erythrocytes, and Spermatozoa Fatty Acid Composition Changes in Young Vegan Men

Abstract

There has been increasing interest in vegan diets, but how this dietary pattern regulates tissue fatty acids (FA), especially in men, is unclear. Our aim was to evaluate the effect of a vegan diet on plasma, erythrocyte, and spermatozoa FA composition in young men. Two groups consisting of 67 young (18-25 years old) men were studied. One group following an omnivore diet but did not consume fish, shellfish or other marine foods (control, n = 33), and another group following a vegan diet (vegan, n = 34) for at least 12 months were compared. Dietary intake was assessed via a food frequency questionnaire and a 24-h recall. FA composition was measured in plasma, erythrocyte phospholipids, and spermatozoa by gas-liquid chromatography. Compared to controls, the vegan group had higher reported intakes of carbohydrate, dietary fiber, vitamins (C, E, K, and folate), and minerals (copper, potassium) but lower intakes of cholesterol, trans FA, vitamins B 6 , D, and B 12 , and minerals (calcium, iron, and zinc). Vegan's reported a lower saturated FA and not arachidonic acid intake, both groups did not intake eicosapentaenoic acid and docosahexaenoic acid (DHA), but vegan's showed a higher alpha linolenic acid ALA intake. Vegans had higher plasma, erythrocyte phospholipid, and spermatozoa ALA, but lower levels of other n-3 polyunsaturated fatty acid (PUFA), especially DHA. Vegans were characterized by higher ALA, but lower levels of other n-3 PUFA, especially DHA in plasma, erythrocytes, and spermatozoids. The biological significance of these findings requires further study.

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

“…A systematic review of 141 studies found that αLNA intakes were similar in omnivores, vegetarians who occasionally consumed meat or fish, and vegans (Neufingerl & Eilander, 2021). EPA and DHA intakes were essentially undetectable in vegans (Neufingerl & Eilander, 2021) which is consistent with the findings of previous detailed dietary analyses (Chamorro et al, 2020a; Welch et al, 2010). Therefore, vegetarian diets may serve as a ‘natural experiment’ to test whether consuming αLNA as the predominant ω‐3 PUFA (most studies do not report SDA or 16:3ω‐3 intakes or tissue levels), can maintain blood and tissue EPA and DHA levels that are sufficient for health.…”

“…EPA, DPAω‐3, DHA are obtained predominantly from foods of animal origin (Baker et al, 2016) and, therefore, individuals who practice dietary choices that exclude animal‐derived foods do not consume these ω‐3 PUFA (Chamorro et al, 2020a; Welch et al, 2010). Diets that are broadly classified as vegetarian differ in the extent to which animal‐derived foods are consumed, while vegan diets exclude all animal‐derived foods (Tonstad et al, 2009).…”

“…Vegetarian diets are associated consistently with lower levels of EPA and DHA in blood lipids from men and women (Burdge et al, 2017; Chamorro et al, 2020a; Chamorro et al, 2020b; Kornsteiner et al, 2008; Neufingerl & Eilander, 2021; Sarter et al, 2015; Welch et al, 2010) (Table 3), and a lower ω‐3 index score (Harris & Von Schacky, 2004; Kornsteiner et al, 2008; Sanders, 2009) compared with omnivores. However, EPA and DHA concentrations in blood and cells from vegetarians are consistently greater than zero (Table 3), despite these fatty acids being absent from the diet (Neufingerl & Eilander, 2021; Sanders & Reddy, 1992; Welch et al, 2010).…”

What Is the Evidence for Dietary-Induced DHA Deficiency in Human Brains?

“…Much has been written on the fatty acid content of human diets, ranging from the speculated palaeolithic diet with high proportions of AA, EPA, DPA n -3 and DHA [ 41 ] to vegan diets with no long chain (LC) n -3 PUFA and relatively high levels of LA and low to modest levels of ALA [ 42 , 43 , 44 , 45 ]. In the US, the adequate intake (AI) values for ALA are 1.6 g/day for ALA in men and 1.1 g/day in women [ 46 ].…”

Science-based policy: targeted nutrition for all ages and the role of bioactives

“…While there is a wide range of intakes for n-3 polyunsaturated fatty acids (PUFA), typical median North American intakes of EPA and DHA are about 100 mg per day while ALA intakes are many times higher at approximately 1600 mg per day [ 109 ]. Although there is some debate in the literature around the efficacy of EPA and DHA synthesis from ALA, clearly ALA can be converted to EPA and DHA [ 69 ] and maintain their blood levels at least to an extent [ 17 , 123 ]. Unlike ALA, the absence of EPA and DHA from the diet does not produce classical signs of deficiency.…”