Kanner Joseph
Department of Food Science, Volcani Center, ARO, Israel.
Mol Nutr Food Res. 2007 Sep;51(9):1094-101. doi: 10.1002/mnfr.200600303.
Lipid oxidation in foods is one of the major degradative processes responsible for losses in food quality. The oxidation of unsaturated fatty acids results in significant generation of dietary advanced lipid oxidation endproducts (ALEs) which are in part cytotoxic and genotoxic compounds. The gastrointestinal tract is constantly exposed to dietary oxidized food compounds, after digestion a part of them are absorbed into the lymph or directly into the blood stream. After ingestion of oxidized fats animals and human have been shown to excrete in urine increase amounts of malondialdehyde but also lipophilic carbonyl compounds. Oxidized cholesterol in the diet was found to be a source of oxidized lipoproteins in human serum. Some of the dietary ALEs, which are absorbed from the gut to the circulatory system, seems to act as injurious chemicals that activate an inflammatory response which affects not only circulatory system but also organs such as liver, kidney, lung, and the gut itself. We believe that repeated consumption of oxidized fat in the diet poses a chronic threat to human health. High concentration of dietary antioxidants could prevent lipid oxidation and ALEs generation not only in foods but also in stomach condition and thereby potentially decrease absorption of ALEs from the gut. This could explains the health benefit of diets containing large amounts of dietary antioxidants such those present in fruits and vegetables, or products such as red-wine or tea consuming during the meal.
食品中的脂质氧化是导致食品质量下降的主要降解过程之一。不饱和脂肪酸的氧化会大量产生膳食晚期脂质氧化终产物（ALEs），其中部分是具有细胞毒性和基因毒性的化合物。胃肠道持续接触膳食中的氧化食品化合物，消化后其中一部分会被吸收进入淋巴或直接进入血液循环。摄入氧化脂肪后，动物和人类尿液中已被证明会排出更多的丙二醛以及亲脂性羰基化合物。饮食中的氧化胆固醇被发现是人类血清中氧化脂蛋白的一个来源。一些从肠道吸收进入循环系统的膳食ALEs似乎作为有害化学物质，激活炎症反应，不仅影响循环系统，还影响肝脏、肾脏、肺和肠道本身等器官。我们认为，饮食中反复摄入氧化脂肪对人类健康构成慢性威胁。高浓度的膳食抗氧化剂不仅可以防止食品中的脂质氧化和ALEs生成，还可以在胃部环境中发挥作用，从而有可能减少肠道对ALEs的吸收。这可以解释富含大量膳食抗氧化剂的饮食（如水果和蔬菜中所含的，或用餐时饮用的红酒或茶等产品）对健康有益的原因。
