In the case of AD, several genetic factors have been identified including the ε4 allele of the APOE gene, which is a strong risk indicator for both AD and coronary artery disease.144,145 Both diseases are also associated with sedentary lifestyle and obesity.143,146 Therefore, the expectation that there will be the nutritional equivalent of a “magic bullet” to ensure normal cognitive function into old age may be premature. The gene discussed is APOE; the disease is obesity due to melanocortin 4 receptor deficiency.