Effects of fruits and vegetables on levels of vitamins E and C in the brain and their association with cognitive performance.

Demographic trends, together with improvements in general health and life expectancy, will greatly change the population structures of most industrialized and developing countries during the next 50 years. By 2050, approximately 30% of people in industrialized countries will be 65 years old or older. Aging is associated with increased risk for neurodegenerative disorders, which can cause significant cognitive and physical impairment and shortened lifespan, thereby causing a burden to society. Diets rich in fruits and vegetables have been shown to improve human well-being and to significantly delay the development of pathologic processes, including neurodegenerative disorders. Foods are important sources of micronutrients, including vitamins E and C, which play crucial roles in optimal cell function. Vitamin E is an important component of biologic membranes, and vitamin C acts as a cosubstrate for several enzymes. Both E and C are involved in the antioxidant defense of cells and actively contribute to the redox status of the cell. The levels of vitamins E and C provided by diet vary significantly. Vegetable oils, nuts and seeds are the main dietary sources of vitamin E, whereas fruits and vegetable are the primary sources of vitamin C. Human trials of varying doses of vitamins E and C, including low, supplemental, and pharmacologic, have found that these nutrients may improve immunity, vascular function, and brain performance. An optimal intake of these nutrients has been associated with decreased risk of developing cognitive impairments associated with aging. This paper will review the scientific literature on the sources, tissue levels and roles of vitamins E and C in cognitive performance and pathologic processes of the central nervous system in the elderly.