Too high or low levels of “good” cholesterol could be correlated with a risk of dementia in the elderly.
- There are two types of cholesterol: high density (HDL) or “good cholesterol”, and low density (LDL) or “bad cholesterol”.
- Scientists have noted an association between high or low HDL cholesterol and the risk of dementia in older adults.
- No link between LDL cholesterol and dementia risk was identified in this study.
Manufactured naturally by the body, cholesterol is a lipid, which participates in maintaining the structure of the membranes of our body’s cells and in the synthesis of certain hormones. There are two types of cholesterol: high density (HDL) or “good cholesterol”, and low density (LDL) or “bad cholesterol”.
A link observed between high or low HDL levels and the risk of dementia
An American study recently observed an association between high or low HDL cholesterol levels and the risk of dementia in older people. The term dementia brings together a group of pathologies including Alzheimer’s disease. Nevertheless, this work, published in the journal Neurologydo not prove that high or low amounts of HDL cholesterol are responsible for the onset of dementia.
During this study, researchers recruited 184,367 people with an average age of 70 years, who did not suffer from dementia at the start of the study. Participants completed a survey on their lifestyle. Their cholesterol levels were measured, on average, 2.5 times during check-up visits. The volunteers were then followed for nine years through electronic medical records. During this follow-up period, 25,214 people developed dementia.
Based on their cholesterol levels, the subjects were divided into five groups. According to scientists, the average HDL cholesterol level was 53.7 milligrams per deciliter (mg/dL). A healthy cholesterol level is considered to be above 40 mg/dL for men and 50 mg/dL for women.
High HDL cholesterol: 15% higher dementia rate than middle group
The US team found that participants with the highest HDL cholesterol levels had a 15% higher rate of dementia than people in the middle group. As for the group with the lowest HDL cholesterol levels, their dementia rate was 7% higher than that of the middle group.“The increase in dementia risk with high and low levels of HDL cholesterol was unexpected, but these increases are small and their clinical significance is uncertain (…) In contrast, we found no association between LDL cholesterol and risk of dementia in the entire study cohort. Our results show that HDL cholesterol has as complex associations with dementia as with heart disease and cancer.”noted Maria Glymour, lead author of the study, Professor and Chair of the Department of Epidemiology at Boston University (United States).
The scientists also indicated that their conclusions took into account other factors that could increase the risk of dementia (alcohol consumption, high blood pressure, cardiovascular disease, diabetes).
