May 18, 2023 – People whose genes make them more likely to have certain kinds of high cholesterol and high blood pressure are at a higher risk for Alzheimer’s disease, according to a new study.
The research is important because it offers concrete ways to identify people at an increased risk and may point scientists toward treatments to prevent the destructive disease. The study, a joint effort by European researchers, was published Wednesday in the journal JAMA Network Open.
The authors conclusively found that people who had genetically linked elevated levels of high-density lipoprotein (HDL, or “good”) cholesterol were at a higher risk of getting Alzheimer’s. The researchers also found that people whose genetics were linked to higher systolic blood pressure were more likely to get the disease. The higher someone’s HDL cholesterol or systolic blood pressure, the greater the risk of Alzheimer’s in the people who carried the affected genes.
The study was considered large in size and included data for 39,106 people with Alzheimer’s and another 401,577 people who did not and who were used for comparison in the analysis. The DNA used in the study came from the European Alzheimer & Dementia Biobank, which includes data from people in 11 European countries. The authors said that the lack of diversity in ancestry among people in the study limited the findings.
Alzheimer's disease is the most common type of dementia, affecting 6.5 million people ages 65 and older in the United States. According to the Mayo Clinic, the brains of people with Alzheimer’s shrink and their brain cells die. The continuous decline affects thinking, behavior, social skills, and the ability to function independently.
Previous research has linked cholesterol and blood pressure levels to Alzheimer’s risk with mixed results, the study authors noted.
Researchers around the world are working to uncover the causes of dementia, and many studies have linked the progressive illness to both genetics and modifiable lifestyle traits. An expert on Alzheimer’s at the University of Texas told CNN this study on its own needs context.
“Overall, I would say it does offer some support for the fact that a lower blood pressure may be good. And the fact that higher HDL, it’s raising some concern about dementia, but there are many explanations for this,” Sudha Seshadri, MD, a neurology professor at the UT Health Science Center in San Antonio, told CNN.
Seshadri, who was not involved in the research, said one possibility is that higher HDL cholesterol could protect people from heart problems, and in turn they live a longer life with more time for dementia to develop.
“It’s research that needs to be replicated and better understood. It’s certainly interesting. But it’s just one piece of information,” she said.