Treating vision loss and lowering LDL cholesterol could help reduce a person’s risk of developing dementia, according to a new report.
The study identified these two new risk factors by looking at meta-analyses, research, and recent studies on the topic. Their analysis revealed about 7% of all dementia cases can be tied to high LDL cholesterol in midlife, and 2% of cases can be linked to untreated vision loss later in life.
This new research was published in The Lancet on July 31 and was authored by 27 dementia researchers who are part of the Lancet Commission on dementia.
In 2020, this same commission identified 12 modifiable risk factors that could also put people at risk of developing dementia.2 Those are:
Lack of physical activity
Smoking
Excessive alcohol consumption
Air pollution
Head injury
Infrequent social contact
Less education
Obesity
Hypertension
Diabetes
Depression
Hearing impairment
These initial 12 risk factors were linked to 40% of dementia cases. However, addressing all 14—including untreated vision loss and high LDL cholesterol—could help prevent or delay up to 45% of dementia cases, the report found.
“These findings provide hope,” lead author Gill Livingston, MBBS, professor of psychiatry of older people at University College London, told Health. “Although change is difficult and some associations might be only partly causal, our new evidence synthesis shows how individuals can reduce their dementia risk.”
Uncovering Additional Dementia Risk Factors
Dementia refers to a range of neurological conditions that affect a person's cognitive ability, including Alzheimer's disease. About 6.7 million Americans over the age of 65 are living with the condition, and estimates suggest that that number could rise to 13.8 million people by 2060.
To identify which conditions or behaviors could be driving some of these dementia cases, researchers looked at existing research and analyses, and examined a total of 14 papers on vision loss and 27 on high cholesterol. They found sufficient evidence that both could join their existing list of risk factors.
In fact, high LDL cholesterol was one of the most significant factors associated with dementia, along with hearing impairment, lower education level, and social isolation in later life.
Addressing these risk factors could lead to greater reductions in dementia risk specifically among minority groups, people with lower socioeconomic status, and in low- and middle-income countries, the researchers noted.
Based on this evidence, they argued that all children should be educated, and people should prioritize cognitive, physical, and social activity both in midlife and late life.
“Dementia isn’t just a result of aging; it’s a complex interplay of genetics, environment, and lifestyle,” David Eagleman, PhD, a neuroscientist at Stanford University and co-founder of BrainCheck and Neosensory, told Health. “Our brains are shaped by everything we do, from our diet to our social lives.”
How Do Vision Loss and High Cholesterol Affect the Brain?
Dementia can occur when nerve cells in the brain stop working properly, leading to cognitive decline. Cardiovascular disease, sedentary lifestyle, hearing loss, and other risk factors can cause a cascade of changes in the brain that increase dementia risk.
The same is true for vision loss and high LDL cholesterol.
“Untreated vision loss can lead to less mental stimulation and reduced social engagement, both of which are key to maintaining brain health,” Joel Salinas, MD, clinical assistant professor of neurology at NYU Grossman School of Medicine and chief medical officer at Isaac Health, told Health. “It’s a bit like letting a muscle weaken because it’s not being used."
Vision loss could also be an indicator of some other disease going on, Salinas added, such as vascular disease.
“High cholesterol, on the other hand, can contribute to the buildup of fatty deposits in the brain’s blood vessels,” he said. “This can lead to blockages, reduced blood flow, and even brain cell damage, all of which increase the risk of dementia.”
The brain is highly sensitive to these disruptions—when it doesn’t receive the right inputs or enough oxygenated blood, its function is compromised.
But the good news is that these are modifiable risks.
“Prevention is our most powerful tool,” Eagleman said. “And that starts with education and awareness. The fact that all the risk factors for dementia are modifiable offers a real opportunity for people to exercise some control over their brain health.”
Early intervention, particularly with modifiable risk factors, could make a big difference in slowing the progression of cognitive decline.
“The brain’s health is cumulative—every day we make choices that either support or undermine our cognitive function,” Eagleman said. “The more we pay attention to the functioning of our brain, the better it will serve us as we age.”
Lowering Your Risk of Dementia
If you think you may have any of these modifiable risk factors for dementia, the best thing to do is get in touch with your healthcare provider, Salinas recommended.
“Addressing vision loss early with corrective lenses, surgery, or other treatments can help maintain engagement with the world around you as well as preserve independence in daily functioning,” he said.
Salinas added that high cholesterol can often be managed through diet, exercise, and medications, and it’s important to create a comprehensive plan with your provider that’s tailored to your specific needs.
Your physician should check for any signs of high LDL cholesterol, vision loss, or other dementia risk factors at your annual wellness visit, even if you don’t have any concerns now. You can ask also your doctor for a cognitive assessment at these visits, regardless of your age or dementia risk, Eagleman said.
“Clinicians can catch subtle signs of impairment, potentially years before symptoms become obvious,” he explained. “It’s in these early stages that lifestyle adjustments—like increased physical activity, mental stimulation, and social engagement—have the most significant impact on preserving brain health.”