Carbohydrates and vitamins from grains and their relationships to mild cognitive impairment, Alzheimer's disease, and Parkinson's disease

Grain-based foods are alleged in the popular media to cause various neurodegenerative conditions, such as mild cognitive impairment (MCI), Alzheimer's disease, and Parkinson's disease. The scientific literature shows that diets containing the right balance of foods, including grain-based foods with an optimal mix of whole and enriched (or fortified) grains, are associated with lower risk for developing a number of neurological conditions. This article, the first of a two-part review, examines the literature on the role of macronutrients, particularly carbohydrates (CHOs), dietary fiber, and vitamins provided by grain-based foods, in the development of various dementias. Studies suggest that grain-based foods and their CHOs and vitamins when incorporated in diets that meet calorie and nutrient needs are important for maintaining brain health and reducing the risk for various dementias. In contrast, excess CHO, fat, or calorie intake from any source, including grain-based foods, may lead to impairment of gl...