High-sugar diets, type 2 diabetes and Alzheimer's disease.

PURPOSE OF REVIEW: Recent findings suggest that high-sugar diets can lead to cognitive impairment predisposing to neurodegenerative disorders such as Alzheimer's disease. This article discusses metabolic derangements induced by high-fructose/sucrose diets and presents evidence for the involvement of insulin resistance in sporadic Alzheimer's disease pathogenesis.

RECENT FINDINGS: There has been much concern regarding the role of dietary sugars (fructose/sucrose) in the development of type 2 diabetes (T2D). Accumulating evidence has also demonstrated a connection between T2D and Alzheimer's disease. The risk for developing T2D and Alzheimer's disease increases exponentially with age and having T2D increases the risk of developing Alzheimer's disease.

SUMMARY: The incidence of T2D increased dramatically over the last decades mainly due to Western lifestyle factors such as lack of exercise and high calorie diets. In fact, high-sugar diets are thought to promote weight gain and insulin resistance predisposing to T2D. To aggravate this scenario, it has been consistently shown that T2D is a risk factor for Alzheimer's disease and both disorders share similar demographic profiles, risk factors, and clinical and biochemical features (e.g. insulin resistance). Therefore, dietary changes can significantly reduce the risk of T2D and Alzheimer's disease and thereby increase the quality of life and improve longevity.