2006年11月26日美国国家科学院院刊（PNAS）发表了美国奥克兰特儿童医院营养与代谢中心埃米斯的综述“微量营养素摄入低可能加速老年人退行性疾病发生” ，作者提出了一项营养学新理论“微量营养素缺乏,损伤三步曲”。
营养不良常常与许多疾病如癌症、心脏病等的发生相联系。人类饮食需要宏量营养素（热量的重要来源）和微量营养素（约40种必需的矿物质、维生素和其他生化物质）。现在的膳食维生素矿物质摄入不足很普遍，大多是由于过多地消耗高能、低微量营养素、加工精细的食物造成的。美国人膳食中维生素矿物质摄入不充分，这可能导致人体慢性代谢紊乱，包括线粒体破坏、脱氧核糖核酸（DNA）损害、染色体破裂，进一步引起氧化损伤和细胞老化，最终引起迟发性疾病（如癌症）发生，这就是“微量营养素缺乏，损伤三步曲”。触发这“三步曲”的微量营养素缺乏可能加速癌症、老化和神经中枢衰退。因此，作者表示服用多种维生素矿物质补充剂是一种确保终身能达到微量营养素膳食推荐摄入量的保健方法。
对老年人而言，他们需要的营养素并不比年轻人少，但老年人的消化机能逐渐退化、各种消化液的分泌减少、消化酶的活性下降、胃肠道吸收功能下降，再加上许多老年人伴有胃肠动力障碍，导致胃口变差，进食量减少。因此，一方面是营养素的摄入减少，另一方面是营养素的吸收减弱，如果不注意营养素的补充则会出现营养素“入不敷出”，最终导致多种营养素缺乏和慢性疾病的发生。如果老年人正在服用一些药物如阿司匹林、消胆胺等干扰营养素的吸收和利用，这就是雪上加霜了。
据全国最新营养调查结果显示，我国60岁以上老年人的营养素补充剂使用率仅为8.5%，远远低于欧美发达国家。因此营养学家呼吁：在提倡均衡营养、合理膳食的前提下，通过合理服用维生素矿物质可以改善营养缺乏状况、预防慢性病的发生和促进健康。
老年人在选购维生素矿物质补充剂时，要特别关注配方是否专为老年人定制，是否强化一些对老年人特别重要的营养素，例如维生素A、E、B6、B12、钙、铬、钾等。大量研究显示，服用多种维生素矿物质补充剂，能有效降低老年患者血压，降低冠心病发生的风险，预防缺血性脑卒中的发生，同时还能增加免疫力，防止感染性疾病的发生。
广州日报
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| | | | | 回答: 缺什么就会老得快?(ZT) 由 鲜葡萄 于 2007-06-02 13:03:25 Bruce N Ames. Low micronutrient intake may accelerate the degenerative diseases of aging through allocation of scarce micronutrients by triage. PNAS 2006(103): 17589-17594.
Abstract：Inadequate dietary intakes of vitamins and minerals are widespread, most likely due to excessive consumption of energy-rich, micronutrient-poor, refined food. Inadequate intakes may result in chronic metabolic disruption, including mitochondrial decay. Deficiencies in many micronutrients cause DNA damage, such as chromosome breaks, in cultured human cells or in vivo. Some of these deficiencies also cause mitochondrial decay with oxidant leakage and cellular aging and are associated with late onset diseases such as cancer. I propose DNA damage and late onset disease are consequences of a triage allocation response to micronutrient scarcity. Episodic shortages of micronutrients were common during evolution. Natural selection favors short-term survival at the expense of long-term health. I hypothesize that short-term survival was achieved by allocating scarce micronutrients by triage, in part through an adjustment of the binding affinity of proteins for required micronutrients. If this hypothesis is correct, micronutrient deficiencies that trigger the triage response would accelerate cancer, aging, and neural decay but would leave critical metabolic functions, such as ATP production, intact. Evidence that micronutrient malnutrition increases late onset diseases, such as cancer, is discussed. A multivitamin-mineral supplement is one low-cost way to ensure intake of the Recommended Dietary Allowance of micronutrients throughout life. |
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