衰老及与年龄相关疾病中的营养干预措施。
Nutrition interventions in aging and age-associated disease.
作者信息
Meydani M
机构信息
Vascular Biology Program, Jean Mayer USDA-Human Nutrition Research Center on Aging at Tufts University, Tufts University, Medford, Massachusetts 02155, USA.
出版信息
Ann N Y Acad Sci. 2001 Apr;928:226-35. doi: 10.1111/j.1749-6632.2001.tb05652.x.
The nutritional status and needs of elderly people are associated with age-related biological and often socioeconomic changes. Decreased food intake, a sedentary lifestyle, and reduced energy expenditure in older adults altogether become critical risk factors for malnutrition, especially protein and micronutrients. Surveys indicate that the elderly are particularly at risk for marginal deficiency of vitamins and trace elements. Changes in bodily functions, together with the malnutrition associated with advancing age, increase the risk of developing a number of age-related diseases. Chronic conditions pose difficulties for the elderly in carrying out the activities of daily living and may increase the requirements for certain nutrients due to changes in absorptive and metabolic capacity. Free radicals and oxidative stress have been recognized as important factors in the biology of aging and of many age-associated degenerative diseases. In this regard, modulation of oxidative stress by calorie restriction, as demonstrated in animal models, is suggested as one mechanism to slow the aging process and the decline of body functions. Therefore, dietary components with antioxidant activity have received particular attention because of their potential role in modulating oxidative stress associated with aging and chronic conditions. Several studies have indicated potential roles for dietary antioxidants in the reduction of degenerative disease such as vascular dementia, cardiovascular disease, and cancer. In support of epidemiological studies, our recent studies indicate that the antioxidant properties of vitamin E and polyphenols present in green tea may contribute to reducing the risk of cardiovascular disease, in part by reducing the susceptibility of low density lipoproteins to oxidation, decreasing the vascular endothelial cell expression of pro-inflammatory cytokines, and decreasing the expression of adhesion molecules and monocyte adhesion. Recently, we also demonstrated that these dietary antioxidants may have a preventive role in cancer, potentially through the suppression of angiogenesis by inhibiting interleukin-8 production and the cell junction molecule VE-cadherin. These findings concur with epidemiologic, clinical, and animal studies suggesting that the consumption of green tea and vitamin E is associated with a reduced risk of cardiovascular disease and cancer, the leading causes of morbidity and mortality among the elderly.
老年人的营养状况和需求与年龄相关的生物学变化以及通常的社会经济变化有关。老年人食物摄入量减少、生活方式久坐不动以及能量消耗降低,共同成为营养不良的关键风险因素,尤其是蛋白质和微量营养素方面。调查表明,老年人特别容易出现维生素和微量元素边缘性缺乏的情况。身体机能的变化,以及与年龄增长相关的营养不良,增加了患上多种与年龄相关疾病的风险。慢性病给老年人的日常生活活动带来困难,并且由于吸收和代谢能力的变化,可能会增加对某些营养素的需求。自由基和氧化应激已被公认为是衰老生物学以及许多与年龄相关的退行性疾病中的重要因素。在这方面,如动物模型所示,通过热量限制来调节氧化应激被认为是减缓衰老过程和身体机能衰退的一种机制。因此,具有抗氧化活性的膳食成分因其在调节与衰老和慢性病相关的氧化应激方面的潜在作用而受到特别关注。多项研究表明,膳食抗氧化剂在减少诸如血管性痴呆、心血管疾病和癌症等退行性疾病方面具有潜在作用。为支持流行病学研究,我们最近的研究表明,绿茶中存在的维生素E和多酚的抗氧化特性可能有助于降低心血管疾病风险,部分原因是降低低密度脂蛋白的氧化敏感性、减少促炎细胞因子的血管内皮细胞表达,以及减少黏附分子表达和单核细胞黏附。最近,我们还证明,这些膳食抗氧化剂可能对癌症具有预防作用,可能是通过抑制白细胞介素-8的产生和细胞连接分子血管内皮钙黏蛋白来抑制血管生成。这些发现与流行病学、临床和动物研究一致,表明饮用绿茶和摄入维生素E与降低心血管疾病和癌症风险相关,而心血管疾病和癌症是老年人发病和死亡的主要原因。