The role of nutrition in Alzheimer's disease.

The aging population is a significant social, medical and economic problem due to increasing prevalence of chronic diseases in elderly population. Alzheimer's disease (AD) is the most common form of dementia and the most common neurodegenerative disease. It is characterized by a progressive deterioration of memory and cognitive function. So far, there is neither an effective prevention nor cure for dementia, so more and more attention is paid to the prevention of this group of diseases, particularly to the appropriate diet. Preventive intervention gives the best results if introduced before the first symptoms of dementia, i.e., around the age of 50. This is when the nutritional status, number of synapses, cognition, and neuropathological changes in the nervous system compensate each other, which increases the chances of staying healthy for a longer period of time. It has been proven that dietary habits, which lead to the development of cardiovascular and metabolic diseases, significantly increase the risk of dementia. On the other hand, a Mediterranean diet rich in antioxidants, fiber and omega-3 polyunsaturated fatty acids may have a protective effect on the neurodegenerative process. The beneficial effect of many nutrients on the course of AD has been demonstrated. These include: glutathione, polyphenols, curcumin, coenzyme Q10, vitamins B6, B12, folic acid, unsaturated fatty acids, lecithin, UA, caffeine and some probiotic bacteria. A diet rich in saturated fatty acids and branched-chain amino acids (BCAA) promotes the progression of dementia. Dietary intervention should be introduced as early as possible to minimize the risk of developing dementia. The Mediterranean and DASH diets have been documented to protect against AD. However, the MIND diet is reported to be much more effective in preventing cognitive decline/dementia than either the Mediterranean or DASH diets alone.