Prof Janet Lord, director of the Institute of Inflammation and Ageing, at the University of Birmingham, and co-author of the research, said: “The immune system declines by about 2-3 % a year from our 20 s, which is why older people are more vulnerable to infections, conditions like rheumatoid arthritis and, potentially, cancer.
“Because the cyclists have the immune system of a 20 -year-old rather than a 70 – or 80 -year-old, it means they have added protection against all these issues.”
The researchers looked at markers in the blood for T-cells, which help the immune system respond to new infections.
These are produced in the thymus, a gland in the chest, which normally shrinks in sizing in adulthood.
‘Out of puff’
They found that the endurance cyclists were rendering the same level of T-cells as adults in their 20 s, whereas a group of inactive older adults were rendering very few.
The researchers believe that being physically active in old age will help people be more responsive to vaccines, and so be better protected against infections such as flu.