There may be a possible link between cholesterol levels and cognitive decline in elderly, revealed a new study.
Researchers at the Heidelberg University's Network Aging Research (NAR) analyzed the data of two independent epidemiological studies. They suggested that people who carry ApoE4 risk factor for Alzheimer's may reduce their risk for cognitive decline by lowering their cholesterol levels.
ApoE stands for apolipoprotein E, a protein that plays a critical role in the metabolism of blood lipids. It also transports cholesterol to the nerve cells.
"Cognitive deficits such as memory lapses can be harbingers of dementia and Alzheimer's but can also occur independently," according to Prof. Dr. Hermann Brenner, Deputy Director of the Network Aging Research (NAR).
The NAR study was led by Prof. Brenner at the German Cancer Research Center (DKFZ) and by epidemiologists Dr. Laura Perna and Dr. Ute Mons. They investigated the extent to which carriers of the E4 allele have a higher risk of cognitive deficits as they age compared to carriers of the other genetic variants.
Blood samples and medical data of two studies namely,ESTHER Study including 1,434 individuals over the age of 70, and the KAROLA Study with 366 participants over 50 were analyzed by the researchers.
The Heidelberg researchers found that the relationship between the ApoE4 risk factor and cognitive deficits, especially memory, was strongest in those with high cholesterol and heart disease.
"One possible explanation for the results could be that the brain is especially sensitive to the effects of ApoE4 once it has already been affected by cardiovascular disease and high cholesterol. It is most likely a complex interaction between the various factors. The ApoE4 allele not only increases the risk of Alzheimer's, but is also associated with an increased risk of arteriosclerosis. Arteriosclerosis, a narrowing of the arteries due to fatty deposits, can cause serious cardiac problems but also supports the development of dementia. It is assumed to be caused by a high level of bad LDL cholesterol in the blood, which often occurs in ApoE4 carriers. High cholesterol, in turn, is an independent risk factor for Alzheimer's" explained Laura Perna.
"Both high cholesterol and cardiovascular disease are potentially avoidable, and in many cases a healthy diet and lifestyle can reduce high cholesterol. Regular exercise and a diet rich in vegetables and fruit and low in animal fat help keep cholesterol levels down. What's good for the heart is also good for the brain and memory. This appears to be especially important for carriers of the ApoE4 risk factor," explained Prof. Brenner.