Left-handed women have earlier age of menopause.

Association between handedness and age of menopause was assessed. A significant difference in the mean age of menopause was found between left-handed and right-handed women. There was a significant correlation between age at menopause and hand preference in right-handed women. These findings suggest that earlier age of menopause in left-handed women may be due to a more active and effective immune system in left-handers.