“Good cholesterol” not so healthy: A new study links good cholesterol levels with dementia in older adults

In a recent study, researchers found that good cholesterol levels in the body could lead to a greater risk of dementia, as per SciTechDaily. The CDC describes dementia as an impaired ability to think, remember or make decisions that affect everyday activities.

Published in Neurology, the medical journal of the American Academy of Neurology, the study suggests that both low and high levels of good cholesterol, also called HDL (high-density lipoprotein) could be significantly connected with dementia risk in older adults.

However, it is important to note that the study only associates good cholesterol with dementia and does not prove that it can cause any kind of dementia, including Alzheimer’s.

---

Good cholesterol levels and dementia: What's the link?

Correlation between good cholesterol and dementia. (Image via Pexels/Kindel Media)

For the study, researchers examined 184,367 people with no dementia issues at the beginning of the study. Each participant was from the Kaiser Permanente Northern California Health Plan and was at an average age of 70.

The participants were asked to fill out a survey and their cholesterol levels were also measured during regular healthcare visits for two years and were followed via electronic health records for nine years. During the course of the study, more than 25,000 participants developed dementia.

Furthermore, researchers divided participants into five groups based on their good cholesterol levels. They found that individuals with the highest HDL cholesterol level were at a 15 percent greater risk of dementia whereas participants with the lowest good cholesterol levels were 7 percent more likely to develop dementia in the long run.

Other than good cholesterol levels, researchers also took some more factors into account that could possibly increase the risk of dementia among older adults. Factors included diabetes, alcohol consumption, smoking, hypertension, and cardiovascular diseases. Surprisingly, the authors found very little correlation between bad cholesterol (LDL) and dementia.

Diabetes and other cardiovascular diseases were taken into account. (Image via Pexels/PhotoMIX Company)

According to the lead author Maria Glymour, the study is very informative as it includes a large number of participants and a long follow-up as well.

"This information allowed us to study the links with dementia across the range of cholesterol levels and achieve precise estimates even for people with cholesterol levels that are quite low or high," Glymour said.

"The elevation in dementia risk with both low and high levels of cholesterol was unexpected," she continued.

In conclusion, the researchers revealed that low and high good cholesterol levels could significantly increase the risk of dementia, though elevation is small and uncertain. On the other hand, however, no correlation was found between bad cholesterol or LDL and dementia in the entire study.