Plant-based diet patterns, genetic predisposition, and the risk of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease has emerged as the most common chronic liver disorder in parallel with the epidemic of obesity1. A healthy lifestyle primarily a weight-loss associated diet is recommended for the management of NAFLD, while prior studies have shown that the Mediterranean diet (MED), which is relatively rich in the plant food source, might favorably affect NAFLD independent of weight loss2. In addition, the green-Mediterranean diet (MED + green tea and Mankai green shake) decreased the intrahepatic fat content compared to the MED alone, which indicates that the plant-based food might be beneficial for NAFLD3. However, whether the plant-based diet is beneficial for the primary prevention of NAFLD remains largely unknown. Plant-based diet patterns characterized by lower intake of meat and higher intake of fruits, vegetables, whole grains, legumes, nuts, and seeds are gaining attention as both health and environmental sustainability benefits4. Previous studies have developed three versions of plant-based diet indices, an overall plant-based diet index (PDI), which emphasized the intake of all plant food; a healthful plant-based diet index (hPDI), which emphasized the consumption of healthful plant-based food such as whole grains, vegetables, nuts, and legumes; and an unhealthful plant-based index (uPDI), which emphasized the consumption of less healthful plant-based food which have been shown to be associated with increased risk of several diseases5. Previous studies have observed the inverse association of PDI and hPDI with the liver fat content and the prevalence of fatty liver6, 7, while evidence on the associations of PDI, hPDI, and uPDI with the incidence of NAFLD is limited. In addition, for individuals with different genetic susceptibility, whether these associations remain the same and whether healthy plant-based food could attenuate the genetic risk is unknown.

非酒精性脂肪性肝病与肥胖流行病并行，已成为最常见的慢性肝病1。对于非酒精性脂肪性肝病（NAFLD）的管理，推荐采取健康的生活方式，主要是与体重减轻相关的饮食。先前的研究表明，地中海式饮食（MED），其植物性食品来源相对丰富，可能对NAFLD产生有益影响，而与体重减轻无关2。此外，与单独的地中海式饮食（MED）相比，绿色地中海式饮食（MED + 绿茶和绿茶粉）降低了肝脏内脂肪含量，这表明基于植物的食品可能对NAFLD有益3。然而，基于植物的饮食是否对NAFLD的初级预防有益尚不清楚。以降低肉类摄入量、增加水果、蔬菜、全谷物、豆类、坚果和种子摄入量为特征的植物性饮食模式，因其对健康和环境可持续性的益处而受到关注4。先前的研究已开发出三种植物性饮食指数的版本，包括整体植物性饮食指数（PDI），强调所有植物性食品的摄入；健康植物性饮食指数（hPDI），强调健康植物性食品如全谷物、蔬菜、坚果和豆类的消费；以及不健康植物性饮食指数（uPDI），强调与多种疾病风险增加相关的不健康植物性食品的消费5。先前的研究观察到PDI和hPDI与肝脏脂肪含量和脂肪肝的患病率呈负相关6，7，而关于PDI、hPDI和uPDI与NAFLD发病率之间关联的证据有限。此外，对于不同遗传易感性的个体，这些关联是否保持不变，以及健康植物性食品是否能够减轻遗传风险尚不明确。