New research suggests that women tend to live longer than men simply because their immune systems are better at fighting off parasitic and bacterial infections. Researchers at the University of Stirling in the UK found that in comparison to members of the fairer sex, males tend to suffer a disproportionate number of “parasitic” infections,
Previous research has shown that men from the UK, US, and Japan are roughly twice as vulnerable to “parasite-induced” death than females – in other countries this risk is thought to be even higher. According to Dr Ian Owens, of Imperial College London, men are less able to fight infection because the way their body works reduces the efficiency of their immune system: “The classic explanation for low immunocompetence in male mammals is that masculinization depends on the male sex hormone testosterone – an immunosuppressant.”
Why testosterone should act in this way remains unclear, although research suggests that the hormone does indeed have a major impact on longevity. Long-term comparison studies of castrated and non-castrated men have shown that castrated men tend to outlive their “intact” peers by as much as 15 years. However, Owens also suggests that men may be more vulnerable to infection simply because they are bigger, and therefore represent a “bigger target” to pathogens.
SOURCE/REFERENCE: Reported by www.bbc.co.uk on the 19th September 2002
