A healthy diet, regular exercise and adequate rest can help your residents live longer. But to reach 110 or more years, they may need a secret weapon. And that weapon appears to be a rare type of T helper cell in their blood, according to a new study.

These helper cells are critical to super longevity, as they help protect older people against the ravages of viruses and tumors, said Kosuke Hashimoto, a researcher with the Riken Center for Integrative Medical Sciences in Japan.

Hashimoto and colleagues isolated immune cells from the blood of seven supercentenarians and five control participants. They then applied a technique called single-cell transcriptomics to assess each immune cell.

“We were especially interested in studying this group of people because we consider them to be a good model of healthy aging,” Hashimoto said.

Full findings appear in Proceedings of the National Academy of Sciences.