A diet deficient in the amino acid methionine has previously been shown to extend lifespan in several stocks of inbred rats.
Scientists report that a methionine-deficient (Meth-R) diet also increases maximal lifespan in (BALB/cJ x C57BL/6 J)F1 mice.
Compared with controls, Meth-R mice have significantly lower levels of serum IGF-I, insulin, glucose and thyroid hormone.
Meth-R mice also have higher levels of liver mRNA for MIF (macrophage migration inhibition factor), known to be higher in several other mouse models of extended longevity.
Meth-R mice are significantly slower to develop lens turbidity and to show age-related changes in T-cell subsets.
They are also dramatically more resistant to oxidative liver cell injury induced by injection of toxic doses of acetaminophen.
The spectrum of terminal illnesses in the Meth-R group is similar to that seen in control mice.
Studies of the cellular and molecular biology of methionine-deprived mice may, in parallel to studies of calorie-restricted mice, provide insights into the way in which nutritional factors modulate longevity and late-life illnesses.