Early-life diet leaves a “nutritional memory” that affects lifespan (fruit fly study, Nature)
A team led by Fumiaki Obata at RIKEN (Japan) found a mechanism that helps explain an old observation: animals on restricted diets early in life often live longer.
What they did: Fruit fly larvae got a low-protein diet (yeast cut from 8% to 1-2%) and were then switched back to normal food as adults.
What they found:
- The protein-restricted flies lived longer than their well-fed siblings, even after returning to a normal diet. The cost was that they were lighter (up to 28% less) and the females laid fewer eggs.
- Adding amino acids back to the larval food erased the lifespan benefit, so the adult body was effectively remembering what it ate as a larva.
- The carrier of that memory is a storage protein called Lsp2, which larvae stockpile for metamorphosis. Less dietary protein means less Lsp2, and the levels stay low into adulthood.
- Silencing Lsp2 in larvae reproduced the effect: fewer ribosomal proteins, slower protein production, and longer life.
- Restricting tyrosine or phenylalanine (which Lsp2 is rich in) was enough to trigger it. Restricting isoleucine did nothing.
Proposed chain: less larval protein → less Lsp2 → fewer ribosomes and slower protein synthesis in young adults → longer life, likely through better proteostasis.
Caveats:
- Only the last step (less protein synthesis → longer life) is firmly established. It’s still unclear why Lsp2 goes preferentially to ribosomes, and they couldn’t directly prove that fewer ribosomes cause the longevity (it would require adjusting ~100 proteins at once).
- Mammals have no direct equivalent of Lsp2. Albumin and globulins are possible functional counterparts, but human albumin isn’t rich in tyrosine or phenylalanine, so any similar mechanism would probably rely on other amino acids.
- The next steps would be mice, then primates, then human correlation studies. There is no basis for “longevity diets” for children.
Source: Ars Technica coverage of the Nature study (Obata et al.).