Research Institute, Hospital for Sick Children, Toronto, ON M5G 1X8, Canada.
Department of Nutritional Sciences, University of Toronto, Toronto, ON M5S 1A8, Canada.
Nutrients. 2023 Sep 23;15(19):4112. doi: 10.3390/nu15194112.
The minimum methionine requirement in the presence of excess dietary cysteine has not been determined in older adults. This study aimed to determine the minimum methionine requirement in healthy older adults using the indicator amino acid oxidation (IAAO) method. Fifteen healthy adults ≥ 60 years of age received seven methionine intakes (0 to 20 mg/kg/d) plus excess dietary cysteine (40 mg/kg/d). Oxidation of the indicator, L-[1-C]phenylalanine (FCO), was used to estimate the mean minimum methionine requirement using a change-point mixed-effect model. There was no statistical difference between male and female requirement estimates, so the data were pooled to generate a mean of 5.1 mg/kg/d (R = 0.46, R = 0.77; < 0.01; 95% CI: 3.67, 6.53 mg/kg/d). This is the first study to estimate the minimum methionine requirement in healthy older adults, which is the same between the sexes and as our lab's previous estimate in young adults. The findings are relevant considering current recommendations for increased consumption of plant foods, which will help to establish the appropriate balance of methionine and cysteine intake required to satisfy the sulphur amino acid requirements of older adults.
在饮食中半胱氨酸过量的情况下，老年人的最低蛋氨酸需求量尚未确定。本研究旨在使用指示氨基酸氧化（IAAO）法确定健康老年人的最低蛋氨酸需求量。15 名年龄在 60 岁以上的健康成年人接受了七种蛋氨酸摄入量（0 至 20mg/kg/d）和过量的饮食半胱氨酸（40mg/kg/d）。使用指示物 L-[1-C]苯丙氨酸（FCO）的氧化来估计平均最低蛋氨酸需求量，使用拐点混合效应模型。男性和女性的需求估计值之间没有统计学差异，因此将数据合并以生成 5.1mg/kg/d 的平均值（R=0.46，R=0.77；<0.01；95%CI：3.67，6.53mg/kg/d）。这是第一项估计健康老年人最低蛋氨酸需求量的研究，男女之间的需求量相同，与我们实验室以前在年轻人中的估计值相同。考虑到当前增加植物性食物消费的建议，这些发现是相关的，这将有助于确定满足老年人硫氨基酸需求所需的蛋氨酸和半胱氨酸摄入量的适当平衡。
