Men have more iron in their bodies and brains than women. These higher levels may be part of the explanation for why men develop these age-related neurodegenerative diseases at a younger age. But why do women have less iron in their systems than men? One possible explanation for the gender difference is that during menstruation, iron is eliminated through the loss of blood. Now, a new study confirms this suspicion and suggests strategies to reduce excess iron levels in both men and women.