Junk food said to cut short lives of birds - human parallels seen

Glasgow (dpa) - An early diet of junk food makes it harder to fight off the ravages of old age, scientists have found. The finding, by scientists from Glasgow University, applies to zebra finches, but could apply to humans too, said the scientists.

The Glasgow study found that birds that had a low-quality diet for the first two weeks of life grew into adults with low levels of anti-oxidants in their blood and died sooner. Anti-oxidants form part of the body's defence against ageing by reducing the damage caused by free radicals.

Animals cannot make anti-oxidants, which include Vitamins A and E, and get them instead from their food. All the birds were fed unlimited quantities of birdseed, but in the case of some of the birds, this was of low quality and lacking in protein and vitamins. All grew up into apparently normal adult birds, said the authors of the Glasgow study, Professor Pat Monaghan and Professor Neil Metcalfe.

But the birds given the low-quality diet in infancy were then less able to make use of the anti-oxidants they had eaten, and had shorter lives.

Metcalfe said: "I think it's not yet clear whether the same things happen in humans, but it's possible. This mechanism is pretty common across species so it's possible. What is true is that early conditions are very important in later life."

In the case of zebra finches, he said, the two-week period covered by the survey was the equivalent to the first 10 years of a human being's life. But the junk food analogy is not exact. In the case of the bird food, the poor quality diet was low in vitamins and proteins - but human junk food is high in fat and can be high in protein, he said.

The study, published today in the Proceedings of the Royal Society, was funded by the Natural Environment Research Council.

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