Assessment
High LDL Cholesterol Could Raise Dementia Risk
“Bad” cholesterol isn’t just a heart concern; it’s a brain issue. Taking steps to lower LDL may help protect both body and mind
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Key takeaways
- High LDL cholesterol is linked to higher dementia risk, with each 40 mg/dL rise tied to an 8 percent increase in lifetime risk.
- Treating high LDL may delay or prevent some dementia cases.
- Lifestyle steps like better sleep, regular activity and diet changes can help lower LDL, sometimes alongside medication.
Keeping cholesterol at a healthy level benefits your heart. More good news: It may also help buffer your brain against dementia, growing evidence suggests.
In the latest Lancet report that looked at ways to prevent Alzheimer’s disease and other types of dementia, high cholesterol was one of two new risk factors added — the other was untreated vision loss. Treating high cholesterol — specifically low-density lipoprotein (LDL), often dubbed the “bad” cholesterol — might prevent or delay 7 percent of dementia diagnoses, the authors estimated.
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The association between LDL levels and dementia used to be more uncertain, says Dr. JoAnn Manson, a professor of medicine at Harvard Medical School and Brigham and Women’s Hospital in Boston. But in recent years, developing research supports LDL cholesterol as a powerful risk factor for dementia, she says, adding, “Generally, what’s bad for the heart is bad for the brain.”
The Lancet report authors cited several observational studies, including a meta-analysis of 17 studies that followed 1.2 million adults younger than age 65 for at least 7 years. For each LDL increase of nearly 40 mg/dL, the adults’ lifetime dementia risk increased by 8 percent.
But public awareness hasn’t caught up with the research. Only about half of U.S. adults ages 40 and older rate managing cholesterol as “very important” for brain health, according to a 2026 survey conducted for the Alzheimer’s Association. Dr. Zaldy Tan, a geriatrician who directs a dementia risk reduction program at Cedars-Sinai in Los Angeles, is not surprised by the knowledge gap.
His program’s participants know that high LDL levels may boost their likelihood of a heart attack or stroke, Tan says. But, he says, “They haven’t connected that LDL is associated with the risk of Alzheimer’s.”
Unpacking the cholesterol-dementia link
In older adults, dementia can be a mix of Alzheimer’s disease and other types, such as vascular dementia, which is a decline in thinking and motor skills due to reduced blood flow to areas of the brain. Research has already shown that lowering LDL levels with a statin can reduce other types of vascular disease, specifically strokes, by as much as 24 percent.
“If you’re protecting the vascular system and lowering risk of stroke, that should manifest itself in some protection against dementia,” Manson notes.
Other research, based on autopsies, shows a connection between higher LDL levels and higher rates of some signs of Alzheimer’s disease in the brain, including amyloid plaques and tau tangles, two types of protein clumps seen in Alzheimer’s. Those brain changes seemed to happen regardless of a person’s genetic risk for Alzheimer’s.
To date, the association between high LDL and dementia is based on observational studies following large groups over time. But research hasn’t yet shown a causal relationship, which would mean that treating LDL levels would reduce dementia, says Dr. David Reuben, who directs the Alzheimer’s and Dementia Care Program at the University of California, Los Angeles.
In that regard, ongoing randomized studies “are going to be incredibly valuable,” Reuben says. One current U.S.-based study splits adults ages 75 and older, who haven’t been diagnosed with cardiovascular disease, into two groups. One group is prescribed a statin and the other a placebo. The number of new dementia diagnoses will be tracked in both groups for as long as 5 years to see whether medication makes a difference.
Tackling LDL levels
New guidelines from the American Heart Association (AHA) and other groups have highlighted the need for earlier screening for all adults, starting at age 19. Roughly one in four has high LDL levels.
But physicians don’t view any single LDL level as “normal” for everyone. Your goal may depend upon many factors, including family and personal history of heart disease and your other medical conditions.
A good rule of thumb to protect both your brain and heart is to keep LDL levels below 100 mg/dL if you haven’t been diagnosed previously with heart disease, Tan says. But your target may be lower: 70 mg/dL or less if you have a cardiovascular risk factor, such as diabetes, or under 55 mg/dL, if you have previously had a heart attack or stroke, Tan says.
It’s never too late to tackle elevated LDL, Reuben stresses. In fact, adults 50 years and older may be particularly likely to benefit given their higher risk of having strokes, including mini strokes, which contribute to dementia, he says. Along with stopping smoking and shedding extra pounds, other lifestyle changes can make a difference in LDL, according to the AHA.
- Get enough restorative sleep: Not enough sleep or irregular sleep has been linked to higher LDL levels. Aim for seven to nine hours each night.
- Move regularly: Find a physical activity that you like doing, whether that’s walking, dancing, cycling or something else that makes you feel good and strive to stick with it.
- Tune up your diet: Start small, swapping in a new ingredient or trying a new nutritious meal each week. The list of cardiovascular-friendly ingredients stretches long: fruits; vegetables; nuts; beans; legumes; whole grains; and various types of lean protein, including fish and meat. Staying Sharp has a 7-day meal plan to help lower cholesterol.
Whether you can rely on lifestyle changes alone, without adding a statin or other cholesterol medication, will likely depend upon how far you are from your LDL goal, Tan says.
Set reasonable expectations: One analysis of 30 studies with a total 2,372 participants, published in 2023 in the European Heart Journal, showed that adults on vegetarian or vegan diets had lower LDL levels than adults who also ate meat or seafood. But the average difference between the two groups was only 11.6 mg/dL. If your LDL is close to the recommended target, you may want to try an improved diet and boosted exercise for 3 to 6 months and see how it goes, Tan says.
Rebooting your lifestyle, along with taking a medication if needed, could have a potential multiplier impact in terms of disease prevention, Manson says, adding, “Controlling LDL will go a long way not only in terms of heart disease but also stroke and dementia.”
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