Sandy, Fava beans contain a 'reducing substance'. Remember oxidation/reduction? Persons with glucose-6-phosphate dehydrogenase deficiency (G6PD) or Mediteranean anemia have difficulty stabilizing the membranes of their red blood cells. Feed them a reducing or oxidizing substance, and a hemolytic crisis ensues (red blood cells fall apart, for the medical jargon challenged). Since this is an x-linked recessive, more males are affected than females, though affected females do exist, since having two copies of the mutant gene is not lethal. This condition seems to be most severe in infancy and childhood. Fava beans are not the only culprits, infections, quinine derivatives, and the antibiotic pediazole can all cause hemolytic crises in individuals with G6PD deficiency. Raw fava beans are more problematic than cooked ones. -- Catherine Watson Genna, IBCLC NYC [log in to unmask]