Researchers at a major U.S. university examined how cholesterol levels relate to brain health. They found that higher levels of cholesterol traditionally labeled as good cholesterol may be linked to a greater risk of developing dementia. The exact biological steps behind this association have not been clarified yet. This observation emerges from recent reports in mainstream media.
Cholesterol is an organic fat-like substance found in the membranes of all animal and human cells. It plays a key role in making steroid hormones, sex hormones, vitamin D, and bile acids that help digest fats. Because cholesterol cannot travel alone in the bloodstream, it relies on carriers called lipoproteins to move through the body.
One well known lipoprotein, HDL, has high density and is commonly called good cholesterol because it helps remove excess fats from the body. New findings suggest that people with higher HDL levels may also face a heightened risk of developing dementia later in life.
In the study, around 185,000 individuals were followed, with an average age of about 70 years. None of the participants started the study with dementia. Participants provided health information through questionnaires every two years and had their cholesterol levels checked regularly. The research followed them for roughly nine years. Within that period, about 25,000 people developed dementia.
Those with HDL cholesterol levels around 65 milligrams per deciliter showed an elevated risk. In men, HDL above 40 mg/dL and in women above 50 mg/dL were associated with about a 15 percent higher chance of developing dementia compared with those with lower HDL levels. Conversely, participants with lower HDL levels, roughly 11 to 41 mg/dL, also showed a greater likelihood of dementia, with a roughly 7 percent increased risk observed in this group.
At this stage, scientists cannot confirm the specific biological pathways through which excess HDL may contribute to dementia. The existing evidence signals a relationship, but causality remains unsettled and requires further investigation with long term and diverse populations. Researchers emphasize that HDL cholesterol is just one piece of the larger puzzle of brain aging and vascular health.
Earlier efforts in pharmacology introduced the first drug aimed at lowering cholesterol overall, underscoring the long-standing interest in cholesterol management for health outcomes. The evolving story about HDL and dementia continues to motivate scientists to explore how lipid balance influences the brain and whether lifestyle, dietary patterns, and genetic factors modify these risks. of Lipid and Brain Health, 2023.