Epidemiological studies show the risk of developing Alzheimer’s disease is increasing in the USA and other countries that are adopting a modern Western diet high in saturated fat, cholesterol, salt, and low in vegetables and fruits.

Alzheimer's disease appears to have much the same risk factors as cardiovascular disease including higher cholesterol levels, obesity, type 2 diabetes, hypertension, elevated homocysteine levels. However, most clinical trials have looked at the impact of individual nutrients on the risk of developing Alzheimer’s disease risk and have been disappointing. People eat diets with complex combinations of nutrients and other substances that may have synergistic effects on risk factors promoting or inhibiting the development of Alzheimer's disease.A recent study found that individuals whose diet includes more salads, nuts, fish, poultry and certain fruits and vegetables and fewer high-fat dairy products, red meats, organ meats and butter were significantly less likely to develop Alzheimer’s disease The lead author of this study Yian Gu, Ph.D., of Columbia University Medical Center studied 2,148 adults (age 65 and older) without dementia living in New York. Participants provided information about their diets and were assessed for the development of dementia every 1.5 years for an average of 4 years. Several dietary patterns were identified with varying levels of 7 nutrients previously shown to be associated with Alzheimer’s disease risk: saturated fatty acids, monounsaturated fatty acids, omega-3 fatty acids, omega-6 fatty acids, vitamin E, vitamin B ₁₂ and folate. Over the next 4 years 253 individuals developed Alzheimer’s disease. A dietary pattern associated with higher intakes of salads nuts, fish, tomatoes, poultry, fruits and cruciferous and dark and green leafy vegetables but low intakes of high-fat dairy, red meat, organ meat and butter.The combination of nutrients in the low-risk dietary pattern reflected a variety of metabolic pathways suspected to play a role in the development of Alzheimer’s disease. Lower levels of vitamin B ₁₂ and folate are associated with higher homocysteine levels that appear to promote Alzheimer’s disease. Dietary factors that promote atherosclerosis, thrombosis or inflammation may alter brain metabolism and membrane functioning leading to the accumulation of beta-amyloid proteins seen in large amounts in the brain's of patients with Alzheimer's disease. “Our findings provide support for further exploration of food combination–based dietary behavior for the prevention of this important public health problem,” concludes Dr. Gu and his colleagues.Bottom Line: There is already plenty of research proving that a diet low in refined carbohydrates, fatty meats and dairy products and higher in minimally processed plant foods will reduce cardiovascular disease and many other ills so this study linking the modern diet to Alzheimer's disease as well provides yet one more reason to encourage everyone to abandon such eating habits