New research suggests that changes in lifestyle could reduce one's risk of developing Alzheimer's disease.

Researchers from Heidelberg University's Network Aging Research found that carriers of the ApoE4 genetic risk factor for Alzheimer's may be able to reduce their increased risk of cognitive decline by reducing their cholesterol level, especially if they also suffer from cardiovascular disease. In Germany, approximately 20 percent of the population carries the ApoE4 risk factor.

"ApoE stands for apolipoprotein E, a protein that plays a critical role in the metabolism of blood lipids. Among other things, it transports cholesterol to nerve cells which the latter require for signal exchange. There are three different genetic variants, or alleles, of the ApoE gene, which contains the blueprint for the ApoE protein. Carriers of the E4 allele, i.e. the ApoE4 genetic variant, have an increased risk of developing Alzheimer's," researchers explaine din the study.

For the study, researchers looked at blood samples and medical data from two epidemiological studies on older adults who also took cognitive tests for memory and concentration capacity. The ESTHER Study included 1,434 individuals over the age of 70, and the KAROLA Study had 366 participants over 50.

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," Laura Perna explains.

In spite of the fact that the relationships are not completely understood, the researchers emphasise the clinical relevance of their findings.

"Both high cholesterol and cardiovascular disease are potentially avoidable, and in many cases a healthy diet and lifestyle can reduce high cholesterol," Prof. Brenner, who led the study, said in a statement.

Regular exercise and a diet rich in vegetables and fruit and low in animal fat help keep cholesterol levels down.

The findings are detailed in the journal Dementia and Geriatric Cognitive Disorders.