The secret to a very long life is in our blood

THE puzzle of how some people live healthily for a century or more may finally have been answered by scientists.

Tests have shown that the blood of “super-agers” is stocked with unusually potent immune cells which attack viruses, bacteria and tumours.

Most people carry CD4 T-cells, which work like sentinels, scouting for invaders, then pumping out chemicals to attract the “soldier” immune cells, which wipe out disease. But a study of seven supercentenarians – all of whom lived to 110 or older – found that a large number of their CD4 T-cells take up arms themselves against pathogens, boosting the immune system.

“Super-agers” had far more of these cells, about 25 per cent, compared with the average of less than 10 per cent.

In the UK, only around 150 people have lived to 110 or beyond.

Dr Kosuke Hashimoto, of the Riken Center for Integrative Medical Science (IMS), in Japan, said: “If we can find the link between the immune system and ageing and longevity, we may be able to contribute to prolonging healthy life expectancies.”

Previous studies have shown that supercentenarians are better able to fight off infections and cancer, which led researchers to wonder if their immune system was fundamentally different.

The research, published in the journal Proceedings of the National Academy of Sciences, found that the supercentenarians had a very high level of cells that are cytotoxic, meaning that they can kill other cells.