Chapter 12 - Nutrition and neurodegenerative diseases: Alzheimer's disease and others

Abstract

Nutrition significantly affects brain development and function during the life of humans. The action of nutrients starts during pregnancy, prenatal, and early childhood. Nutritional deficiencies during early life can cause permanent cognitive deficits in human populations. Furthermore, some supplements are helpful in improving brain and body development, such as zinc and polyunsaturated fatty acids (PUFAs). Nutrition is also involved in preventing neurodegenerative diseases in the older population. The Mediterranean diet (MeDiet) is most effective in preventing neurodegeneration. Mechanism of action appeared correlated to the moderate caloric restriction and higher ingestion of fruit, vegetables, and polyphenols such as extra virgin olive oil and resveratrol. The most efficient endocrine-metabolic factor to influence neuron efficiency seems to be insulin activity, although other essential hormones are involved (such as estradiol, testosterone, and IGF-1). Dietary supplementation and food intake education positively impacted the quality of life and cognitive function in patients with AD. Malnutrition and undernutrition are aggravating factors of the neurodegenerative disease. Losing weight in patients with cognitive impairment has the most deleterious effect on brain function and mortality. The administration of PUFA is ineffective, while vitamins are critical, except for vitamin E and vitamin B at higher doses. Further studies are necessary to evaluate the cause and effect of a single component of nutrition and neurodegenerative disease, with a robust statistical analysis on low risk of bias.