Gu and colleagues1 identified a dietary pattern associated with lower risk of AD. This dietary pattern includes higher intake of salad dressing, nuts, fish, tomatoes, poultry, cruciferous vegetables, fruits, and dark green leafy vegetables and lower intake of high-fat dairy products, red meat, organ meat, and butter. It is similar to the Mediterranean diet, adherence to which is also associated with reduced risk of developing AD.2 Previously, Buijsse et al3 reported that elderly men from Crete, in the Mediterranean south of Europe, had “consistently lower levels of indicators of oxidative stress and iron status and higher concentrations of major antioxidants” than elderly men from Zutphen in the north of Europe. In particular, serum ferritin levels, a useful marker of body iron stores,4 were 2-fold lower in men from Crete (69.8 μg/mL) than in men from Zutphen (134.2 μg/mL). We have proposed that age-associated increase in body iron stores is a pivotal event in AD pathogenesis and progression.5 We predict that dietary patterns similar to the Mediterranean diet that reduce the risk of AD will also be associated with lower body iron stores, as indicated by reduced serum ferritin levels. Unfortunately, iron status was not an endpoint in the study of Gu and colleagues.1 Given the therapeutic interest in iron chelators for neurodegenerative diseases including AD,6 and in controlled phlebotomy to safely reduce body iron stores and avoid iron deficiency,4 design of future epidemiological studies of diet and AD should consider the potential importance of iron status.
Dwyer BE, Zacharski LR, Balestra DJ, Lerner AJ, Perry G, Zhu X, Smith MA. Potential Role of Iron in a Mediterranean-style Diet. Arch Neurol. 2010;67(10):1286-1288. doi:10.1001/archneurol.2010.245