A naturally occurring substance found in common foods could help strengthen the immune response to vaccines in some older adults, according to new research published in Aging Cell. The compound, called spermidine, appears to combat the biological aging of immune cells that makes vaccination less effective as people grow older.
Scientists at the Max Delbrück Center and University of Oxford conducted a pilot study with 40 adults aged 65 and older who had received three COVID-19 vaccine doses. Half took six milligrams of spermidine daily for 13 weeks, while the other half received a placebo.
About a quarter of the participants had produced very weak antibody responses despite three vaccinations. Their immune cells showed signs of biological aging, including elevated DNA damage and cellular senescence, a process where damaged cells stop functioning normally but accumulate in the body.
Among those vaccine nonresponders given spermidine, immune markers improved substantially. Participants developed higher antibody levels against the virus and showed stronger neutralizing activity against multiple viral variants. The supplement also reduced markers of immune system aging and increased autophagy, a cellular recycling process that removes damaged material.
Spermidine is produced naturally by the body and exists in foods including wheat germ, mushrooms, parmesan cheese, and cheddar cheese. Earlier research has suggested the molecule supports cellular maintenance mechanisms that decline with age.
Dr. Ghada Alsaleh, an associate professor at Oxford, noted that while many older adults respond well to vaccines, some fail to develop strong protection even after repeated doses. "Biological aging of immune cells may be one reason why this happens," Alsaleh said. "Our findings suggest that spermidine could help restore aspects of immune function in this group."
The supplement appeared safe with no adverse effects reported. However, the researchers cautioned that larger trials are needed to confirm whether spermidine can consistently improve vaccine responses and whether similar benefits apply to other vaccines, such as the seasonal flu shot.
Author Jessica Williams: "A cheap, food-based compound improving vaccine efficacy in seniors would be a genuine win, but we're still in the early stages and bigger studies will make or break this story."
Comments