- Recent evidence has investigated how different aspects of health and behaviors can play a role in dementia risk.
- One study found that getting vaccinated against shingles can help lower this risk, and another found that maintaining low cholesterol levels can help as well.
- Another piece of research indicated that not getting enough deep sleep — in particular REM and slow-wave sleep — can increase risk.
- A separate study also found that atrial fibrillation raises the risk of dementia and that this link is stronger for younger individuals.
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Many factors — both genetic and environmental — can affect a person’s risk of developing dementia throughout their lifetime.
Newer research has found that age, genetics, a history of vascular and neurodevelopmental disorders, as well as some viral infections can increase this risk. Meanwhile, keeping certain biomarkers in check and adopting healthier lifestyle habits can help lower this risk.
Medical News Today looks at four recent studies — one with Spanish participants, another from South Korea, one from Wales, England, and another a longitudinal study from the U.S. — to examine how and why these aspects of Health and behaviors can influence a person’s risk of developing dementia in older age.
Viral infections have been linked to a heightened risk of dementia, and one particular infection is shingles. Shingles happens some time after an initial chicken pox infection, when the dormant
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What’s more interesting is that this risk reduction was more apparent in women — they experienced a much greater reduction in new diagnoses of dementia than men.
The researchers attributed this greater protective effect to “biological differences in immune response” between both sexes.
Although the study touts the shingles vaccine as a potentially cost-effective way to prevent or delay dementia, more research is needed to confirm these preliminary findings and compare the results to existing pharmaceutical interventions.
One other important question that remains about the study is whether the newer shingles vaccines can offer the same protection. The participants in this study received Zostavax, the older vaccine that used a live-attenuated form of the virus. The current vaccine in use is Shingrix, a recombinant zoster vaccine.
Previous research has shown an increased risk of dementia in people with AFib, and a newer study builds on these findings.
A recent study presented at the European Heart Rhythm Association (EHRA) 2025 in March indicated that atrial fibrillation (AFib) may be linked to an increased risk of developing dementia, underscoring the importance of getting early treatment.
In the study, participants with AFib had a 21% greater risk of developing dementia if they were below 70 years old. These participants were also at a 36% increased risk for early-onset dementia, or getting diagnosed before age 65. This suggests that this risk association is stronger for younger adults.
Paul Drury, MD, a board certified cardiologist and associate medical director of electrophysiology at MemorialCare Saddleback Medical Center in Laguna Hills, CA, who was not involved in the study, called the study’s results interesting but pointed out that more research is needed to rule out other comorbidities and other treatments that may affect the findings.
“There does, however, [appear to] be a much stronger association with dementia the earlier a person is diagnosed with AFib, which implies that AFib has potential mechanisms that can lead to dementia,” he said.
A new study published in the BMJ Journal of Neurology, Neurosurgery, and Psychiatry found that people with low-density lipoprotein cholesterol (LDL-C) levels — but not to an extreme — had a lower risk of developing dementia. In fact, this protective effect was enhanced if the person was taking cholesterol-lowering statins.
LDL cholesterol is referred to as “bad” cholesterol, as it is the type that can lead to a buildup of plaques in arteries—also known as atherosclerosis—which has been linked to an increased risk of stroke, heart attacks, and other cardiovascular diseases.
According to the study results, people whose LDL-C levels were below 70 milligrams per decliliter (mg/dL) had a 26% lower risk of all-cause dementia and a 28% lower risk of Alzheimer’s disease-related dementia compared to people whose LDL-C levels were greater than 130mg/dL.
This risk reduction was less significant in people whose LDL-C levels were at 55 mg/dL, as they only saw an 18% reduced risk, while those below 30 mg/dL saw no reduction in dementia risk at all.
“This is an interesting observation indicating a potential threshold effect, where reducing LDL-C beyond a certain point does not further improve cognitive outcomes. It aligns with previous research indicating that while high LDL-C is harmful, excessively low levels may not offer additional protective effects,” explained Emer MacSweeney, MD, CEO and consultant neuroradiologist at Re:Cognition Health, who was not involved in this study, to MNT.
A recent study added to the evidence that clearing the buildup of junk proteins in the brain via a critical process — deep sleep — can help decrease Alzheimer’s risk.
The authors of this study examined the association between specific sleep phases and the atrophy of brain regions vulnerable to Alzheimer’s.
The results of this study suggest that not spending enough time in slow-wave and REM sleep may significantly reduce the volume in the inferior parietal lobule (IPL). Changes in this region of the brain have been associated with progressing from Healthy aging to Alzheimer’s.
As Chelsie Rohrscheib, PhD, a sleep expert, neuroscientist, and sleep consultant at Wesper, who was not involved in this study, told MNT:
“Sleep has many crucial biological functions and is especially important for cell and tissue repair, brain maintenance, learning and memory, cognition, and brain waste clearance. Most of these functions occur during stage 3 slow wave sleep and REM sleep. All of these processes are crucial for maintaining brain health and reducing the risk of Alzheimer’s disease.”
