Dec. 1, 2023 – People with unusually high levels of HDL, the so-called “good cholesterol,” may be more likely to develop dementia, new research suggests.
Very high HDL cholesterol levels were not common among study participants and likely were linked to metabolic problems, such as diabetes, and not diet, according to a research summary from Monash University in Australia, where research team leaders work.
With more than 18,000 participants ages 65 years and older, the study was one of the largest yet to analyze the potential relationship between HDL cholesterol and dementia. Results of the study were published Thursday in The Lancet Regional Health – Western Pacific.
The study defined very high HDL cholesterol as greater than 80 mg/dL. The ideal range is typically 40 to 60 mg/DL for men and 50 to 60 mg/dL for women.
People with levels higher than 80 mg/dL had a 27% increased risk of developing dementia during an average follow-up period of 6.3 years, compared to people in the optimal range. People age 75 years or older who had very high levels had an increased risk of dementia of 42%.
Study participants did not have heart disease or dementia at the start of the study. They also were screened out of participating for having a physical disability, life -threatening illness, or existing cognitive problems.
“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,” said lead author Monira Hussain, MBBS, PhD, MPH, a senior research fellow at Monash’s School of Public Health and Preventive Medicine, in a statement. “It may be beneficial to consider very high HDL cholesterol levels in prediction algorithms for dementia risk.”
Dementia is a term that refers to a range of cognitive problems that typically arise as people age, the most common of which is Alzheimer’s disease. Some symptoms of dementia are memory loss, language problems, and difficulties with problem-solving and other thinking abilities that are severe enough to interfere with daily life, according to the Alzheimer’s Association. More than 5.8 million people in the U.S. have dementia, and that number is predicted to rise to 14 million by 2060, according to the CDC.