摄入富含多胺的食物能够延缓果蝇因年龄引起的记忆力下降，10月《自然—神经科学》上的一项研究得出该结论。很多食物都含有多胺，研究证明，多胺会随着人年龄增大而自然减少，此外，其对其他模式生物的寿命也有促进作用。此项最新研究则进一步证明增加饮食中的多胺能够帮助延缓与年龄相关的记忆力减退。
大多数器官利用多胺调节细胞的生理过程比如细胞存活和细胞繁殖。哺乳动物细胞自身能够合成多胺——虽然目前相关的原始分子机制几乎仍是未知。另外，人们已经知道大脑中的多胺水平会随着年龄增大而降低。
由于多胺能够延长无脊椎模式生物的寿命，Stephan Sigrist, Frank Madeo等人便研究果蝇的这种记忆力减退能否通过摄入多胺发生逆转。他们发现，当较老果蝇难以记住预示着轻微电击的特定线索时，那些经过高含量多胺喂养的较老果蝇则没有发生这种问题，它们在这项任务中的表现同那些较年轻的果蝇一样。研究人员还注意到，多胺会通过促进细胞自噬作用（一种细胞的自我吞噬过程，会清理掉有缺陷的细胞器）的方式调节平衡这种有益影响（生物谷Bioon.com）。
生物谷推荐的英文摘要
Nature Neuroscience DOI:10.1038/nn.3512
Restoring polyamines protects from age-induced memory impairment in an autophagy-dependent manner
Varun K Gupta，Lisa Scheunemann，Tobias Eisenberg，Sara Mertel，Anuradha Bhukel，Tom S Koemans，Jamie M Kramer，Karen S Y Liu，Sabrina Schroeder，Hendrik G Stunnenberg，Frank Sinner，Christoph Magnes，Thomas R Pieber，Shubham Dipt，André Fiala，Annette Schenck，Martin Schwaerzel，Frank Madeo & Stephan J Sigrist
Age-dependent memory impairment is known to occur in several organisms， including Drosophila， mouse and human. However， the fundamental cellular mechanisms that underlie these impairments are still poorly understood， effectively hampering the development of pharmacological strategies to treat the condition. Polyamines are among the substances found to decrease with age in the human brain. We found that levels of polyamines (spermidine， putrescine) decreased in aging fruit flies， concomitant with declining memory abilities. Simple spermidine feeding not only restored juvenile polyamine levels， but also suppressed age-induced memory impairment. Ornithine decarboxylase-1， the rate-limiting enzyme for de novo polyamine synthesis， also protected olfactory memories in aged flies when expressed specifically in Kenyon cells， which are crucial for olfactory memory formation. Spermidine-fed flies showed enhanced autophagy (a form of cellular self-digestion)， and genetic deficits in the autophagic machinery prevented spermidine-mediated rescue of memory impairments. Our findings indicate that autophagy is critical for suppression of memory impairments by spermidine and that polyamines， which are endogenously present， are candidates for pharmacological intervention.
