Could a Protein in the Blood Help Explain How Diet Influences Longevity?

Researchers are investigating how reduced protein production may extend lifespan through a process known as proteostasis—the cell’s ability to keep proteins properly functioning.

How reduced protein production may extend lifespan

“Reduced translation and reduced protein production translates into longer lifespans,” says Obata. In this context, translation refers to the process cells use to make proteins. Obata argues that the resulting increase in lifespan depends on improved proteostasis.

The researchers are focusing on Lsp2, a protein whose association with ribosomes remains poorly understood. Ribosomes are the cellular structures responsible for producing proteins.

“What we need to figure out is why it is desirable for this Lsp2 to go to the ribosome,” says Obata. “This part is still a mystery.”

The team also could not directly demonstrate that reducing the number of ribosomes would restore ribosome levels and extend lifespan. Ribosomes contain roughly 100 different proteins, and manipulating all of them at once is not currently technically possible, Obata told Ars.

Why a longevity diet for infants is not realistic

Even if the mechanism is fully explained, feeding infants a diet designed to promote longevity is unlikely to become possible in the near future. One major obstacle is that mammals, including humans, do not have a direct equivalent of Lsp2.

Could humans have a similar nutritional memory system?

Obata believes that the most functionally similar human proteins may be albumin and globulin. Together, they account for about 90% of the proteins in human blood.

Like Lsp2, albumin is produced in large quantities, turns over rapidly, and responds to the amount of protein consumed. These characteristics raise the possibility that albumin could carry a form of “nutritional memory”—a lasting molecular record of dietary conditions.

What researchers need to test next

Testing whether albumin or related proteins have nutritional memory will require several stages of research.

“We need to do this in mice first, because we can directly manipulate the protein, and then maybe in primates,” says Obata. Human studies would then need to determine whether albumin levels are associated with longevity.

Even if albumin is confirmed as a nutritional memory carrier in humans, researchers would still need to identify the precise mechanism. The relevant amino acids could also differ between humans and the organism studied, since human albumin is not particularly rich in tyrosine or phenylalanine.

“We have to find out which amino acids are key, which molecular carriers correspond to Lsp2, and whether there is really a link between human longevity and diet,” says Obata.

The remaining questions

For now, the potential connection between dietary protein, ribosomes, proteostasis, and lifespan remains an area of ongoing research. Key questions include why Lsp2 associates with ribosomes, which proteins carry nutritional memory in humans, and whether protein levels are genuinely linked to human longevity.

Nature, 2026. DOI: 10.1038/s41586-026-11031-3