Alzheimer's disease: risk and protection

Only four risk factors for Alzheimer's disease can be regarded as confirmed - old age, family history of dementia, apo-E genotype and Down syndrome. Other disputed risk factors with some supporting evidence include ethnic group, head trauma and aluminium in drinking wafer. Possible protection factors, such as anti-inflammatory drugs, oestrogen replacement therapy and a high education level, are of great interest because they suggest possible preventive action.