As we grow older, our immune system gradually becomes weaker. This natural change means older adults are more likely to become seriously ill from infections and often do not develop as much protection after vaccination as younger people.
Scientists are now exploring whether natural compounds can help the aging immune system work more effectively.
A new study published in Aging Cell suggests that spermidine may be one promising option. The research was led by scientists from the Max Delbrück Center and the University of Oxford, who found that this naturally occurring compound improved several signs of immune function in some older adults after COVID-19 vaccination.
Spermidine is produced naturally inside human cells and can also be obtained from foods such as mushrooms, wheat germ, soy products, aged cheeses, and whole grains. Previous laboratory studies have suggested that it helps cells stay healthy by supporting autophagy, a natural process that removes damaged cell components and recycles useful materials.
Healthy autophagy becomes less active with age. At the same time, aging immune cells begin to accumulate damage and lose their ability to respond quickly to infections. Scientists refer to this gradual decline as immunosenescence, which is one reason vaccines sometimes provide less protection in older people.
To investigate whether spermidine could reverse some of these age-related changes, researchers enrolled 40 healthy volunteers aged 65 years and older. After participants received their third COVID-19 vaccine dose, they were randomly assigned to receive either a daily 6-milligram spermidine supplement or a placebo for 13 weeks.
The study found that about one in four participants produced only weak antibody responses despite receiving three vaccine doses. These individuals also had more biological signs of aging in their immune cells, including DNA damage and markers of cellular senescence, a state in which cells stop functioning normally but remain in the body.
For participants with poor vaccine responses who received spermidine, the results were encouraging. Their antibody levels increased, their antibodies became better at blocking several coronavirus variants, and important markers linked to immune aging decreased. The researchers also found stronger activity of the cell-cleaning process known as autophagy.
The supplement was well tolerated throughout the trial, and no important safety problems were reported. Even so, the researchers emphasize that this was an early pilot study involving only a small number of participants, so the findings should be interpreted carefully.
The next step will be larger clinical trials involving many more volunteers. Scientists also want to learn whether spermidine could strengthen responses to vaccines against influenza, pneumonia, and other infectious diseases that are especially dangerous for older adults.
Overall, the findings offer an interesting new approach to healthy aging. Rather than changing the vaccine itself, researchers hope to improve the body’s ability to respond to vaccination by making aging immune cells healthier.
If future studies confirm these results, spermidine could become a simple addition to strategies that help older adults stay protected from infectious diseases.
If you care about health, please read studies that vitamin D can help reduce inflammation, and vitamin K could lower your heart disease risk by a third.
For more health information, please see recent studies about new way to halt excessive inflammation, and results showing foods that could cause inflammation.
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