Cholesterol and dementia: how 'good' cholesterol may increase your risk of developing dementia

A new study has revealed that whilst ‘good’ cholesterol lowers the risk of heart disease, according to a study published in the journal Lancet Regional Health - Western Pacific, ‘good’ cholesterol might contribute to developing dementia.

HDL cholesterol, or High-density lipoprotein is known as ‘good’ cholesterol because it absorbs cholesterol in the blood and carries it back to the liver which flushes it out of the body. Whereas ‘bad’ LDL or low-density lipoprotein cholesterol, builds up in the arteries increasing the risk of heart disease or stroke.

In a study covering more than 18,000 people aged over 65 over a period of six years, researchers found that 4.6% of participants got dementia. People who were Among people who were 75 years and older, the risk of developing the disease was 42%. Overall, anyone with high HDL levels had a 27% increased risk of dementia. Other risk factors like physical activity levels, education, diabetes, smoking or alcohol consumption were corrected and the scientists said the increased risk was separate from all the traditional dementia risk factors.

Very high levels of HDL were considered to be 80 mg/dL or higher - and a healthy adult woman should have 50 mg/dL or higher and it is 40 mg/dL or higher for men. However, the study identified those with very high HDL levels were uncommon and it was more likely to be linked to an underlying metabolic disorder than be diet-related.

Dr Monira Hussain, who worked on the study, said: "While we know HDL cholesterol is important for cardiovascular health, this study suggests that we need further research to understand the role of very high HDL cholesterol in the context of brain health. It may be beneficial to consider very high HDL cholesterol levels in prediction algorithms for dementia risk.”

Dr Corey Bradley, a cardiologist, told MedicalNews Today: “What we are learning now is that there is a lot more nuance to HDL’s role in the body. As a result, I usually explain to patients that it is more "neutral" than "good."'