限食、壽命與老化

Diet Restriction, Longevity and Aging

黃青真(Ching-Jang Huang) ； 謝明哲(Ming-Jer Hsieh)

《中華民國營養學會雜誌》 14卷1&2期 (1989/04) Pp. 63-85

https://doi.org/10.6691/JCNS.198904_14(1_2).0007

摘要

限制給食不但使傳統實驗老鼠活的更久，亦使無特定病原(Specific Pathogen Free, SPF)老鼠、正常小白鼠、具自體免疫傾向小白鼠(NZB/NZW)、遺傳性肥胖小白鼠以及自發性高血壓老鼠(Spontaneous Hypertensive Rat, SHR)等之平均壽命顯著地延長，其老年期的存活率亦大大的增高。在這些動物模式中，限食顯著地延遲伴隨老化而來的生理變化，如肌肉、骨骼生理功能之減低，脂肪綑胞對激素之敏感度降低和免疫機能的低下等，且降低了諸如腎臟疾患之老年疾病的罹患率以及腫瘤的發生率等。限制給食對自體免疫傾向小白鼠更顯著抑制了免疫複合體的形成，使其對腎絲球體的傷害顯著減低。因此，限食顯然有延緩老化程式(aging process)之效應。即使在成年之後再開始進行限食，仍可有效地使壽命延長。
可以延長老鼠壽命的餵養方法，主要能量攝取量比自由攝食少20%至60%，而其他養營素則充分供應，亦即非充分營養而無營養不良，限食程度愈嚴重，動物之平均壽命愈長。只限制蛋白質、礦物質或脂肪對延長壽命之效果有限。能量來源對壽命的影響亦甚小。
限食之可以延長壽命的機制應非降低生長速率或減少體脂肪的含量，亦非減少每克體重每日之攝食量或降低每單位瘦體質之代謝速率所致。目前仍需要更多研究方可確定降低遊離基傷害、促進基因表現與蛋白質轉換，保留DNA修補能力等學說是否為限食之所以能延長壽命之主要機制。

並列摘要

During the past fifty years, it has been repeatedly reported that diet restriction markedly increased longevity and survival rate at old age. This phenomenon were observed in various rodent models including: conventionally raised rats, SPF (Specific Pathogen Free) Fischer 344 rats, long-lived mice of inbred and hybrid strains, autoimmune-prone short-lived mice, genetically obese mice and SHR (Spontaneous Hypertensive Rat) rats, etc. In these animal models, diet restriction retarded age-related decline in physiological and immunological functions, delayed the occurrence of most age-associated diseases or slowed their progression, as well as decreased age-related tumor incidence. In autoim-mune-prone short-lived mice, the onset of progressive immunologically based renal disease, vascular disease, lymphoproliferative disease, and even certain malignancies can be delayed or eliminated completely by calorie intake restriction. These evidences suggested that diet restriction effectively retarded the aging processes. Even restriction starting from adulthood can also prolong life span and slow the aging processes.
The life-prolonging diet restriction regimen required feeding animals with energy intake 20% to 60% less than those of the ad libitum fed animals. All the other nutrients must be supplied in adequate amounts, thus resulting in ”under-nutrition without malnutrition”. The more severe the animals were restricted, the longer they lived. Restriction of other diet components was much less or not effective in life prolongation. Longevity was not altered by changing energy sources.
Evidences indicated that diet restriction prolongs life span of animals probably not by retarding growth or decreasing adiposity, nor by reducing energy intake per gram body weight or lowering metabolic energy per unit lean body mass. Further studies will be needed to characterize other possible mechanisms underlying the life-prolonging effects of diet restriction, such as decreasing the free radical damages, enhancing gene expression and protein turn over, and retaining DNA repair capacity, etc.

並列關鍵字

diet restriction ； aging process ； life span