Abstract：
The EAT-Lancet Commission\'s planetary health guidelines suggest a reduction in the consumption of animal-source foods (ASFs) for better health and more sustainable food systems. ASFs are highly nutrient dense, therefore suited to address the widespread issue of micronutrient deficiencies, particularly in low-resource settings where diets are predominantly plant based. ASFs are also believed to contain the meat factor, a substance enhancing the absorption of micronutrients from plant-based foods. We conducted a scoping review with the objective of systematically mapping the available evidence on the meat factor. The MEDLINE/PubMed and Web of Science databases were searched for literature published up to September 2021. Articles eligible for inclusion were all studies assessing the effect of adding ASFs and/or ASF fractions on micronutrient absorption from a plant-based meal or the overall diet in animal models and human subjects. Screening and data extraction were performed, and results were charted into 12 categories. We identified 77 articles eligible for inclusion, 52 of which were conducted in human subjects, 24 in animal models, and 1 in both. The addition of muscle tissue and muscle tissue fractions to single plant-based meals steadily increased absorption of iron and zinc across studies. The efficacy of the meat factor in increasing iron and zinc absorption in the overall diet is less clear. No clear differences emerged between red meat, poultry, and fish in promoting the meat factor effect. No clear evidence indicates that milk and egg products contain the meat factor. Our review highlights the importance of muscle tissue for the potential of the meat factor to enhance absorption of micronutrients of concern. Although the literature supports including sustainable and economically accessible forms of these ASFs into the diet, we found limited studies in resource-poor countries and of diets with low meat intake.
摘要：
EAT-Lancet委员会的行星健康指南建议减少动物源食品（ASF）的消费，以改善健康和更可持续的食品系统。ASF是高度营养密集的，因此适合解决广泛的微量营养素缺乏问题，特别是在低资源环境中，饮食主要以植物为基础。ASF也被认为含有肉类因子，一种增强植物性食物中微量营养素吸收的物质。我们进行了范围审查，目的是系统地绘制有关肉类因素的现有证据。在MEDLINE/PubMed和WebofScience数据库中搜索了截至2021年9月发表的文献。符合纳入条件的文章是评估在动物模型和人类受试者中添加ASF和/或ASF级分对来自基于植物的膳食或总体饮食的微量营养素吸收的影响的所有研究。进行了筛选和数据提取，结果分为12类。我们确定了77篇有资格纳入的文章，其中52个是在人类受试者中进行的，24在动物模型中，两者都是1。在整个研究中，将肌肉组织和肌肉组织部分添加到单一植物基餐中稳步增加了铁和锌的吸收。肉类因子在增加整体饮食中铁和锌吸收的功效尚不清楚。红肉之间没有明显的差异，家禽,和鱼类在促进肉类因素方面的作用。没有明确的证据表明牛奶和蛋制品含有肉类因素。我们的评论强调了肌肉组织对于肉类因子增强关注的微量营养素吸收的潜力的重要性。尽管文献支持将这些ASF的可持续和经济上可获得的形式纳入饮食中，我们发现在资源贫乏的国家和肉类摄入量低的饮食方面的研究有限.
