Alzheimer’s disease (AD) begins to manifest itself by memory deficits and difficulty in abstract thinking. As the brain lesions spread, the cognitive deficits progressively worsen and problems of orientation and behavior, loss of autonomy, and eating disorder appear. Weight loss is a nutritional problem frequently observed in patients with dementia of Alzheimer type, as demonstrated in clinical practice and in numerous studies. But nutritional problems should not, perhaps, be seen only as a consequence of this disease: in fact, nutrition seems to influence cognitive function and behavior. Numerous works have reported an association between alterations in cognitive function and vitamin status (principally, the B group vitamins and the products involved in their metabolism, and the antioxidant vitamins), consumption of cholesterol and fatty acids, and overall energy intake. Table 11.1 summarizes the most significant studies published in 2002.