Evidence for health benefits of plant phenols: local or systemic effects?
Evidence for health benefits of plant phenols: local or systemic effects?
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DOI：
10.1002/jsfa.900
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发表时间：
2001-07-01
影响因子：
4.1
通讯作者：
Hollman, PCH
中科院分区：
文献类型：
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作者：
Hollman, PCH
植物酚类主要是类苯丙素途径的产物，并且包括多种化合物：肉桂酸、苯甲酸、类黄酮、原花色素、芪类、香豆素、木脂素和木质素。它们是强抗氧化剂，可以防止对生物分子如DNA、脂质和蛋白质的氧化损伤，这些生物分子在癌症和心血管疾病等慢性疾病中发挥作用。植物酚类可能会干扰癌症过程的所有阶段，可能导致癌症风险降低。在观察性研究中仅对黄酮醇进行了研究。七项研究中有五项显示，黄酮醇摄入量与随后的心血管疾病（CVD）呈负相关。四分之一的研究中只发现了对癌症的保护作用。因此，流行病学的证据还不允许一个坚定的决定，参与黄酮醇的病因，无论是心血管疾病或癌症。黄酮醇的流行病学表明它具有全身效应。茶作为各种酚类的丰富来源，其流行病学显示结肠癌的不一致数据，这也不支持植物酚类的局部效应。植物酚类物质的吸收和生物利用度研究不足。膳食类黄酮被认为是吸收不良，因为它们作为P-糖苷（糖的共轭物）存在。然而，与葡萄糖结合增强人体吸收。黄酮和其他植物酚类被结肠细菌广泛代谢：环状结构被裂解，产生一系列酚酸，然后被吸收。人体研究表明，只有约1%的吸收良好的类黄酮与完整的类黄酮骨架一起排泄到尿液中。需要回答的主要问题是，在体外系统中发现的有效浓度是否真正反映了生理浓度。(C)2001年，化学工业协会。
Plant phenols are mostly products of the phenylpropanoid pathway and comprise a large variety of compounds: cinnamic acids, benzoic acids, flavonoids, proanthocyanidins, stilbenes, coumarins, lignans and lignins. They are strong antioxidants and might prevent oxidative damage to biomolecules such as DNA, lipids and proteins which play a role in chronic diseases such as cancer and cardiovascular disease. Plant phenols may interfere with all stages of the cancer process, potentially resulting in a reduction of cancer risk. Only flavonols have been investigated in observational studies. Five out of seven studies showed an inverse association of flavonol intake with subsequent cardiovascular disease (CVD). A protective effect against cancer was only found in one out of four studies. Thus the epidemiological evidence does not yet allow a firm decision on the involvement of flavonols in the aetiology of either CVD or cancer. The epidemiology of flavonols points to a systemic effect. The epidemiology of tea, as a rich source of various phenols, shows inconsistent data for colon cancer, which also does not support a local effect of plant phenols. The absorption and bioavailability of plant phenols have been inadequately studied. Dietary flavonoids were thought to be poorly absorbed because of their presence as P-glycosides (conjugates of sugars). However, conjugation with glucose enhanced human absorption. Flavonoids and other plant phenols are extensively metabolised by colonic bacteria: the ring structure is cleaved, giving a range of phenolic acids which are then absorbed. Human studies showed that only about 1% of a well-absorbed flavonoid was excreted with an intact flavonoid backbone into urine. Major questions to be answered are whether the effective concentrations found in in vitro systems really reflect physiological concentrations. (C) 2001 Society of Chemical Industry.