Fly Study Suggests Fasting May Not Be Key To Longer Life

What to believe, what to believe. The new buzz...

"Many of the studies that have concluded consuming a calorie-restricted diet extends lifespan have been done under sterile lab conditions and therefore don't properly reflect reality where we are bombarded every day by a vast array of pathogens, some of which seize hold and cause infection.

So Schneider and Ayres decided to investigate this further by measuring the appetites of infected and uninfected fruit flies: in both cases some flies had been reared on a calorie restricted diet while others had not.

Curiously, fruit flies are useful models for studying human reactions to pathogens since much of their immune response parallels ours.

They found that living on a reduced calorie diet altered the flies' response to infection, but in ways that depended on what the flies were infected with: the response was different to different pathogens...

Schneider said:

'There's evidence that caloric restriction seems to rev up various individual components of the immune system.'

'But in the few studies where diet-restricted animals actually have been infected experimentally, they fared poorly,' he added.

Scheider and Ayres concluded that:

'The work reported here should raise a cautionary flag, as it demonstrates that diet restriction can have complex effects on the realized immune response of a diet-restricted animal.'"

Restricted Calories, unrestricted infections.