Researchers at the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS) at the University of Oxford found that spermidine, a compound the body makes naturally and that is abundant in aged cheese, mushrooms, lentils, chickpeas and broccoli, can improve vaccine responses in some older adults. The mechanism is not that spermidine fights infection directly, but that it reduces molecular markers of "immunosenescence" — the gradual deterioration of the immune system that makes vaccines less effective as we age.
The work, published in the journal Aging Cell, builds on a well-established cellular process called autophagy, often described as the cell's housekeeping system, in which damaged components are broken down and recycled. Spermidine is known to stimulate autophagy, and the team's experiments suggest that by refreshing immune cells this way, older immune systems can mount a stronger response to a vaccine they would otherwise shrug off. In laboratory and patient-derived models, spermidine reduced the molecular signatures associated with immune aging and improved the magnitude of the vaccine response.
Why this matters is straightforward: older adults are precisely the group most vulnerable to influenza, shingles, pneumonia and other vaccine-preventable illness, yet they are also the group for whom vaccines reliably produce the weakest protection. A safe, food-derived compound that nudges the aging immune system back toward a younger response profile could eventually become a simple adjunct given alongside standard vaccinations — though the researchers stress that clinical translation still requires rigorous human trials to confirm dosing and real-world benefit.
Knowledge takeaway: Spermidine, a natural compound plentiful in aged cheese, mushrooms, lentils and broccoli, improved vaccine responses in older adults by lowering molecular markers of immune-system aging (immunosenescence); the effect is tied to autophagy, the cell's recycling process that refreshes aging immune cells; the finding, reported in Aging Cell by Oxford's NDORMS, points to a possible food-derived way to make vaccines work better in the elderly, but human clinical confirmation is still needed.