What is the secret of long life? Reducing calorie intake by 30 per cent is thought to lead to a longer lifespan, but for many, this can mean (1) ... a starvation-like diet. However, scientists are now developing a drug which they believe can switch on a particular gene that has the same effect without the pain. A recent (2) ... of centenarians (долгожители) found, though, that many in the over-100 age group had led unhealthy lifestyles for a long period of their lives. For these people a long life is the (3) ... of a longevity gene and scientists have been working on a drug that can imitate this gene. Or is it all down to the mind? Some scientists believe that if we "think" younger our bodies will follow. Research has shown that by (4) ... people imagine they are twenty years younger, many of the (5) ... of ageing actually go into reverse.
Какое слово (словосочетание) пропущено на позиции (4)?