创作:mildbreeze 审核:mildbreeze 02月28日
  • 目前关于饮食限制(DR)延缓衰老的进化理论认为,生物体在DR期间会从生长繁殖向身体的维持和修复倾斜,从而延长寿命;
  • 对果蝇进行不同频率的DR和富足食物的饮食切换,发现长期DR的果蝇,在恢复丰富饮食后,反而会死亡率升高;
  • 这种现象普遍存在于11种不同基因型的果蝇中,且不同基因型可对DR效果有不同影响;
  • DR延缓衰老的机制更可能是避免过度营养造成的身体损伤,DR引起的身体适应性变化可能存在隐性成本。
有理论认为,生物体在食物供应不足时,会将能量投资于维持和修复身体,为食物增加时做好准备。按此理论推断,当生物体从热量限制重新回到营养充足的状态时,会比一直营养充足的个体在生存和/或繁殖方面更有优势。然而Science Advances上发表的一项研究,通过对果蝇进行不同频率的饮食切换试验发现,饮食限制延缓衰老促进长寿的机制,更可能是避免因过度营养而造成的身体损伤。该研究还提示,与持续性热量限制或富足饮食相比,较长间隔的饮食切换反而不利于健康。这些发现对于研究热量限制和间歇性禁食等饮食干预具有参考意义。
Science advances [IF:13.116]

The hidden costs of dietary restriction: Implications for its evolutionary and mechanistic origins



02-21, Article

Abstract & Authors:展开

Dietary restriction (DR) extends life span across taxa. Despite considerable research, universal mechanisms of DR have not been identified, limiting its translational potential. Guided by the conviction that DR evolved as an adaptive, pro-longevity physiological response to food scarcity, biomedical science has interpreted DR as an activator of pro-longevity molecular pathways. Current evolutionary theory predicts that organisms invest in their soma during DR, and thus when resource availability improves, should outcompete rich-fed controls in survival and/or reproduction. Testing this prediction in Drosophila melanogaster (N > 66,000 across 11 genotypes), our experiments revealed substantial, unexpected mortality costs when flies returned to a rich diet following DR. The physiological effects of DR should therefore not be interpreted as intrinsically pro-longevity, acting via somatic maintenance. We suggest DR could alternatively be considered an escape from costs incurred under nutrient-rich conditions, in addition to costs associated with DR.

First Authors:
Andrew W McCracken

Correspondence Authors:
Mirre J P Simons

All Authors:
Andrew W McCracken,Gracie Adams,Laura Hartshorne,Marc Tatar,Mirre J P Simons