Hughes D A
Immunology Group, Nutrition, Health and Consumer Science Division, Institute of Food Research, Norwich Research Park, Norwich, Norfolk, NR4 7UA, United Kingdom.
Nutrition. 2001 Oct;17(10):823-7. doi: 10.1016/s0899-9007(01)00638-4.
The colorful group of compounds known as carotenoids are present in many plants, where they provide photoprotection and act as accessory pigments in photosynthesis. Many epidemiologic studies have shown strong associations between diets rich in carotenoids and a reduced incidence of many forms of cancer, and that finding led to the suggestion that the antioxidant properties of those compounds might help protect immune cells from oxidative damage, thus enhancing their ability to detect and eliminate tumor cells. Since the early 1980s, there have been reports supporting that hypothesis. However, more recently, after large prospective studies did not show protective effects of beta-carotene supplementation, more attention has been given to studies defining optimal levels of intake that can be achieved within a well-balanced diet. The latest intervention studies have suggested that, in well-nourished, healthy individuals, a moderate level of carotenoid supplementation is neither beneficial nor harmful. However, supplementation might be appropriate in undernourished or less healthy individuals, particularly if they are elderly. Future studies comparing supplements with real foodstuffs, combined with postgenomic technologies, will help define optimal intakes for different sectors of the population.
被称为类胡萝卜素的一组色彩斑斓的化合物存在于许多植物中，它们在植物中起到光保护作用，并在光合作用中充当辅助色素。许多流行病学研究表明，富含类胡萝卜素的饮食与多种癌症发病率的降低之间存在密切关联，这一发现促使人们提出这样的观点：这些化合物的抗氧化特性可能有助于保护免疫细胞免受氧化损伤，从而增强它们检测和消除肿瘤细胞的能力。自20世纪80年代初以来，一直有报告支持这一假设。然而，最近，在大型前瞻性研究未显示补充β-胡萝卜素具有保护作用之后，人们更加关注确定在均衡饮食中能够实现的最佳摄入量的研究。最新的干预研究表明，在营养良好、健康的个体中，适度补充类胡萝卜素既无益处也无害处。然而，在营养不良或健康状况较差的个体中，尤其是老年人，补充类胡萝卜素可能是合适的。未来将补充剂与天然食物进行比较的研究，结合后基因组技术，将有助于确定不同人群的最佳摄入量。
