It's a known fact that excessive consumption of sugar and fat may lead to heart problems. Now, another study featured on the Huffington Post suggests that this kind of diet may also contribute to Alzheimer's Disease (AD) risk.

Together with her colleagues, researcher Suzanne Craft from Wake Forest School of Medicine worked with 47 older adults approaching their 70s, half of whom already had mild cognitive impairment. For four weeks, they were randomly assigned to follow either a high-sugar, high-fat diet, or a low-sugar, low-fat diet with the same amount of calories. A lumbar puncture was performed before and after the study in order to compare levels of amyloid-beta in the cerebral spinal fluid.

Amyloid-beta is one of the major causes of AD. It is normally cleared from the brain when it attaches to a protein called apolipoprotein E. Failure to attach to the said protein turns amyloid-beta into a lipid depleted (LD) amyloid-beta and becomes toxic to the brain.

Prior to the trial, participants with cognitive impairment had higher LD amyloid-beta levels than those who were mentally healthy. After four weeks, those who were assigned the high-sugar, high-fat diet had an increase in LD amyloid-beta levels, whereas those who had the low-sugar, low-fat diet managed to show lower LD amyloid-beta levels. However, those who were genetically at risk for AD showed no change.

“The types of food we eat, particular dietary patterns that happen over long periods of time, are likely to have a substantial impact on our brains to the point where they may either protect or increase your risk of developing late-life brain disease like Alzheimer's disease,” Craft says.

(Photo by specialoperations via Flickr Creative Commons)