The simple, surprising habits that can slow your immune ageing by years

In the centre of your chest lies a tiny, thyme-leaf shaped gland that plays a big role in how long you're likely to live.

Known as the thymus, it acts as the body’s training ground for a group of white blood cells called T cells, which serve a very important function.

We rely on T cells throughout our lives to seek and destroy cancers, eliminate pathogens and marshal our immune responses. T cells are birthed in the bone marrow, but it’s the thymus that trains them to become specialised, organised killing machines.

What’s most remarkable, however, is that until relatively recently the thymus was assumed to serve virtually no purpose at all in adulthood.

Many doctors considered it to be obsolete and would routinely remove it during cardiac surgery on children (the size and position of the thymus during childhood makes it difficult to reach the heart).