Can Cholesterol Control Prevent Alzheimer's Disease?

A new study found that the same genetic risk factors that make some people more likely to have high cholesterol may also increase the risk of Alzheimer's disease.

Without knowing the causes of Alzheimer's disease, scientists from the Universities of Washington, St. Louis and California, San Francisco, are currently conducting the largest study on DNA, looking for risk factors preprogrammed.

"We already know that one of the genes associated with the risk of Alzheimer's disease involves molecules involved in the movement of cholesterol in the body," said the scientists, confirming that the relationship between cholesterol and the Alzheimer's disease could be stronger than previously thought.

Through the new genetic analysis, scientists have discovered that a small group of genes, associated with a high risk of Alzheimer's disease and heart disease.

One of the forms of the APOE4 gene, for example, is currently an indicator of the risk of Alzheimer's disease that we know, this type of APOE4 gene being associated with an increased risk of Alzheimer's disease. But they are also present in healthy people and therefore far from being an indicator of the disease.

"The nature of the risk varies depending on the presence of this gene in some healthy people, but we also find a high prevalence among people with the disease," said co-author of the study, Celeste Carth, psychiatrist in St. Louis. This part of the DNA affects the brain and its function, but we know how closely it relates to cardiovascular disease. "

When the APOE4 gene functions properly and provides a specific protein, this protein is bound to the lipids that make up the lipid proteins. These molecules help to ensure that the fat passes correctly into the bloodstream.

These water soluble lipidic proteins are essential to ensure that the "good" cholesterol of fatty acids is transferred to the tissues that absorb it into energy and that the "bad" cholesterol is redirected to the liver.

If the "bad" cholesterol does not return properly to the liver, it can accumulate in the blood vessels, thus limiting the flow of blood.

This, of course, increases the pressure on the heart, which pumps very hard blood through narrow passages. Therefore, those who have a defect in this gene are more likely to have high cholesterol.

The gene could also be linked to the accumulation of amyloid plaques in the brain, which scientists suspect to be one of the underlying causes of Alzheimer's disease.

The authors of the new study, conducting a DNA research of 1.5 million people, discovered that 90% of DNA could be associated with risk factors for heart disease, diabetes , high cholesterol and high BMI.

"This study did two things to strengthen this relationship between fat-related genes and the risk of heart disease and Alzheimer's," Dr. Karsh said.

"Fat is very important for healthy brain cells of all kinds because it plays an important role in the ability of cells to carry these pathogenic proteins, as well as in their ability to break down these pathogenic proteins," he said. .

The research team also found that some genetic variants related to the immune system increased the risk of Alzheimer's disease.

In theory, a low fat diet would mean a shortage of cholesterol that should be eliminated from the bloodstream, which somewhat reduces the importance of the genetic ability to transport cholesterol from the blood.

Thus, maintaining a low cholesterol level can also help reduce the risk of accumulation of amyloid proteins in the brain and thereby reduce the risk of developing Alzheimer's disease. It also suggests that cholesterol-controlling drugs may be helpful in reducing the risk of Alzheimer's disease.