Krajcovicová-Kudlácková M, Simoncic R, Béderová A, Brtková A, Magálová T, Barteková S
Výskumný ústav výzivy, Bratislava.
Cas Lek Cesk. 1999 Aug 30;138(17):528-31.
Low protein quality and quantity is reported to be a possible risk of alternative nutrition. Pulses contain 18-41% of methionine in relation to reference protein, moreover, its content in cereals is by one half lower. Therefore vegetarians and vegans may have an insufficient intake of sulphur-containing amino acids that may subsequently affect glutathione values (precursors of its synthesis).
In groups of adults on an alternative diet--lactoovovegetarians (n = 47) and vegans (n = 44) aged 19-62 years with average duration on a vegetarian or vegan diet of 7.6 and 4.9 years, respectively, glutathione levels (GSH) were measured in erythrocytes (spectrophotometrically), as well as the activity of GSH-dependent enzymes. As nutritional control (n = 42) served an average sample of omnivores selected from a group of 489 examined, apparently healthy subjects of the same age range living in the same region. One to low protein intake (56% of RDA) exclusively of plant origin significantly lower levels of total proteins were observed in vegans with a 16% frequency of hypoproteinaemia (vs 0% in omnivores). In comparison to omnivores a significantly lower glutathione level was found (4.28 +/- 0.12 vs 4.84 +/- 0.14 mumol/g Hb, P < 0.01). Lactoovovegetarians because of their protein intake in adequate amounts with a 27% proportion of animal proteins (dairy products, eggs) consume a balanced mixture of amino acids, which is reflected in total protein levels similar to omnivores and significantly higher values of glutathione -5.26 +/- 0.12 mumol/g Hb, P < 0.05 (intake of glutathione in diet, higher consumption of fruit and vegetable in comparison to omnivores). A sufficient supply of glutathione as the substrate for enzymatic reactions of hydrogen peroxide or lipid hydroperoxide catabolism, as well as for detoxication of xenobiotics, was reflected in lactoovovegetarians in a significantly higher activity of glutathione-peroxidase and glutathione-S-transferase in erythrocytes.
Low protein intake exclusively of plant origin, significantly lower protein levels with 16% frequency of hypoproteinaemia, significantly lower glutathione values in blood in comparison to omnivores and lactoovovegetarians confirm the risk of a vegan diet also in adult age.
据报道，蛋白质质量和数量较低是替代营养的一个潜在风险。与参考蛋白质相比，豆类含蛋氨酸量为18%-41%，而且其在谷物中的含量要低一半。因此，素食者和纯素食者可能含硫氨基酸摄入不足，这可能会影响谷胱甘肽值（其合成的前体）。
在替代饮食的成年人群组中——19-62岁的乳蛋素食者（n = 47）和纯素食者（n = 44），其素食或纯素食的平均时长分别为7.6年和4.9年，通过分光光度法测量红细胞中的谷胱甘肽水平（GSH）以及谷胱甘肽依赖性酶的活性。作为营养对照组（n = 42），选取了从489名受检者中选出的一组杂食者作为平均样本，这些杂食者是来自同一地区、年龄范围相同的明显健康的受试者。纯素食者中仅植物来源的低蛋白摄入量（占推荐膳食摄入量的56%）导致总蛋白水平显著降低，低蛋白血症发生率为16%（杂食者为0%）。与杂食者相比，发现谷胱甘肽水平显著更低（4.28±0.12对4.84±0.14μmol/g血红蛋白，P<0.01）。乳蛋素食者由于其蛋白质摄入量充足，动物蛋白（乳制品、蛋类）占比27%，摄入的氨基酸混合均衡，这体现在总蛋白水平与杂食者相似，且谷胱甘肽值显著更高——5.26±0.12μmol/g血红蛋白，P<0.05（饮食中谷胱甘肽的摄入量，与杂食者相比水果和蔬菜消费量更高）。乳蛋素食者红细胞中谷胱甘肽过氧化物酶和谷胱甘肽-S-转移酶的活性显著更高，这反映出有充足的谷胱甘肽作为过氧化氢或脂质氢过氧化物分解代谢酶促反应的底物，以及作为外源性物质解毒的底物。
仅植物来源的低蛋白摄入量、低蛋白血症发生率为16%时显著更低的蛋白水平、与杂食者和乳蛋素食者相比血液中显著更低的谷胱甘肽值，证实了成年期纯素食饮食也存在风险。
