Japanese researchers say mice lacking vitamin C age four times faster than normal mice, suggesting the vitamin might help slow aging in humans.

The scientists from the Tokyo Medical and Dental University and the Tokyo Metropolitan Institute of Gerontology analyzed a specific protein that decreases as aging proceeds and found it was the same as an enzyme that synthesizes vitamin C, the Mainichi news service reported.

After six months of observation, researchers said normal mice without the protein were all still alive, but half of the ones lacking the protein had died of old age.

Subsequently the researchers determined the level of vitamin C in the mice without the protein was one-tenth that of the level in normal mice.

Since humans are unable to produce vitamin C in their body even if they have the protein, the results of the experiment do not directly indicate vitamin C is effective in preventing aging in humans. But researchers told Mainichi mice that do not have the protein might be utilized in research into human aging.

The study is reported online in the electronic edition of the Proceedings of the National Academy of Sciences.