Scientists have recently developed ways to measure your immune age. Fortunately, it turns out your immune age can go down as well as up. And there are some simple ways to turn back the clock on your immune system.
One study in older adults showed that those who got 10,000 steps a day on average had neutrophils as good as a young adult.
Exercise also has benefits for your T cells. Before they are released onto active duty, T-cells mature in a little-known organ called the thymus gland in your chest. The thymus degenerates over time, resulting in a drop-off in the number of T cells.
Physical activity has a huge effect on the rate of this degeneration. A study found that amateur cyclists aged between 55 and 79 had youthful thymus glands and their T-cell counts were similar to those of much younger people.
Another key factor in your immune age is your gut bacteria. There is good evidence that poor gut health is a cause of premature ageing and that a healthy microbiome can reduce your immune age. Eating a healthy, varied diet rich in fibre, plant matter and fermented foods can help maintain a healthy community of gut microbes.
Your body has a highly evolved, intricate defence system that’s effective at keeping you well, but only if you look after it.