High Calorie Diets Increase The Risk Of Alzheimer’s Disease

In August 2002, a study published in the journal Archives of Neurology suggested that those who consume high calorie diets might be up to 50% more likely to develop Alzheimer’s disease than those who consume low calorie diets.

The study involved 980 individuals aged 65 or older from the northern Manhattan area in New York. The participants were followed for an average of four years and during that period, 242 of the individuals developed Alzheimer’s disease.

Those individuals who were in the highest quartile for calorie intake (average intake of 1870 kcal) were found to be 48% more likely to develop Alzheimer’s disease than those in the lowest quartile (average intake of 758 kcal) while those in the second highest quartile for calorie intake (average intake of 1363 kcal) were 20% more likely to develop Alzheimer’s disease than those in the bottom quartile.

Calories derived from fat were found to be the most strongly associated with Alzheimer’s disease. Individuals in the highest quartile for mono-unsaturated fat intake were 60% more likely to develop Alzheimer’s disease and individuals in the highest quartile for saturated fat were 30% more likely to develop Alzheimer’s disease than those in the lowest quartiles.

Carbohydrate and protein intake on the other hand appeared to be unrelated to Alzheimer’s disease risk.

Those who carry the ApoE-4 allele, which increases the risk of Alzheimer’s disease, appeared to be at the greatest risk when consuming a high calorie diet. Those with the ApoE-4 allele and who were in the highest quartile for calorie intake were 2.3 times more likely to develop Alzheimer’s disease than those with the ApoE allele in the lowest quartile for calorie intake.

It is thought that calorie restriction helps reduce oxidative damage in the body by reducing the number of free radicals present. Oxidative damage to cells in the brain (neurons) may be one of the processes related to the development of Alzheimer’s disease. Those who consume calorie restricted diets also tend to have higher levels of the SIRT1 protein in the brain. SIRT1 is thought to be associated with a longer lifespan and improved health in old age.

Caloric restriction may also help preserve brain function by increasing the activity of certain DNA repair enzymes and upregulating the action of antiapoptotic proteins such as NAIP that help protect against neuronal cell death.