In Caenorhabditis elegans, experimentally raising reproductive effort under dietary restriction using food odour cues did not diminish the survival benefit, contradicting the long-standing view that restriction extends life by diverting resources from reproduction to somatic maintenance. An evolutionary model based on Hamilton's forces of selection indicates that suppressed fertility under restriction intensifies selection against mortality, while shorter lifespans under abundant food may arise through mutation accumulation. The mechanism behind restriction-based longevity therefore appears evolutionary rather than strictly budgetary.
Key Points
- Increased reproduction under dietary restriction did not reduce survival benefits
- Fertility suppression reflects restraint in poor environments, not resource reallocation
- Mutation accumulation may explain shorter lifespans under abundant food
Longevity Analysis
Dietary restriction protocols have long been justified by a presumed trade-off between reproductive output and tissue maintenance, a premise these data do not support. If longevity under restriction derives from altered selection pressures rather than a fixed energy budget, then the repair and renewal capacity activated during periods of scarcity may not require the hormonal and reproductive costs often assumed to accompany it. The practical implication is that nutrient timing and intake strategies should be evaluated on the signals they generate across metabolic and endocrine function, not on an accounting model of energy diverted from one function to another.
Original published by Wiley Aging Cell, by Sara D. Irish, Annabel Kimberley, Simone Immler, Jacob Moorad, Alexei A. Maklakov .