Mice that were fed for nine months on the diet, which represents the nutritional content of most fast food, developed abnormalities in the brain similar to those observed in the brains of Alzheimer’s patients, said the study published in a doctoral thesis from the Swedish medical university Karolinska Institutet (KI).
The research offers some indication of the role that diet could play in prevention of the disease which currently affects an estimated 5.2m Americans.
Researcher Susanne Akterin, a postgraduate at KI Alzheimer’s Disease Research Center, told FoodNavigator-USA.com: “Several studies have been published during the last years linking diet with the development with Alzheimer's disease and dementia and especially too much cholesterol have been found to be particularly bad.
“This is probably because the brain is an organ that is especially rich in cholesterol and where cholesterol has many functions, and therefore is tightly regulated.
“When you eat too much cholesterol this regulation will be disturbed, leading to many negative effects.
“All kinds of food that contain a lot of fat, sugar and cholesterol is likely to have the same bad consequences.
“Considering the lack of effective medication for this dreadful disease, to prevent the disease from developing in the first place would be desirable.”
Akterin said the most common risk factor in Alzheimer’s disease is a variant of a certain gene that governs the production of apolipoprotein E, which transport cholesterol. The gene variant is called apoE4 and is found in 15-20 percent of the population.
The research team studied mice that had been genetically modified to mimic the effects of apoE4 in humans for her doctoral thesis.
They noted an increase in phosphate groups attached to tau, a substance that forms the neurofibrillary tangles observed in Alzheimer’s patients, which prevent the cells from functioning normally and eventually leads to their death.
They also saw indications that cholesterol in food reduced levels of another brain substance, Arc, a protein involved in memory storage.
Akterin said: “We now suspect that a high intake of fat and cholesterol in combination with genetic factors, such as apoE4, can adversely affect several brain substances, which can be a contributory factor in the development of Alzheimer’s.
“All in all, the results give some indication of how Alzheimer’s can be prevented, but more research in this field needs to be done before proper advice can be passed on to the general public.”
Previous research has shown that a phenomenon known as oxidative stress in the brain and a relatively low intake of dietary antioxidants can also increase the risk of Alzheimer’s.
Thesis: “From cholesterol to oxidative stress in Alzheimer’s disease: A wide perspective on a multifactorial disease”
Author: Susanne Akterin, Department of Neurobiology, Care Sciences and Society, KI Alzheimer’s Disease Research Center, Karolinska Institutet.