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Researchers are looking into the benefits of statins as a treatment for dementia. Alistair Berg/Getty Images
  • Researchers are reporting that statins may help slow cognitive decline in some people with dementia.
  • However, they noted that the findings were part of an observational study and more research is needed.
  • Experts say the benefits of statins in the prevention of cardiovascular disease may be a factor in lower dementia symptoms.

According to a new study, people with dementia experienced cognitive decline at a slower rate if they were also given a lipid-lowering statin.

However, it’s important to note this is an observational study so researchers say they are hesitant to recommend statin therapy for people with Alzheimer’s or other forms of dementia at this time.

In their study, researchers looked at medical information from more than 15,500 people with Alzheimer’s or mixed dementia who also qualified for lipid-lowering treatment. Nearly 11,000 of them were given statins.

The researchers reported that the people who took statins performed better in cognitive tests.

“We hypothesized that patients on statins would have better cognitive outcomes and this was what we found in our results,” said Dr. Sara Garcia-Ptacek, a docent of neuroscience and assistant professor at the Department of Neurobiology, Care Sciences and Society at the Karolinska Institutet in Sweden as well as a research leader of the current study.

“We did find that patients [taking the drug] simvastatin (Zocor) fared better cognitively but only in the analyses where we included patients on long-term treatment,” she told Healthlline. “Looking at patients who had recently started treatment we did not find this benefit of simvastatin, but statins in general were still associated with better cognition than no treatment.”

There are still many unanswered questions.

“Going forward we need to understand why this is happening and define which patient groups benefit,” Garcia-Ptacek said. “Why did the results of simvastatin differ in patients on long-term vs recent treatment? How does cholesterol and the ApoE genotype influence this association? ApoE genotype is a risk factor for dementia and codes a cholesterol transporter, so this particular genetic factor might be key to defining patient groups for future interventions.”

Further research is needed to better understand the association between statin therapy and its effects on Alzheimer’s and other forms of dementia.

“We need to replicate these findings in other cohorts, both within and outside of Sweden,” said Garcia-Ptacek. “We want to define the patients who benefit. Is cholesterol, ApoE, or some other marker useful to selecting patients? There have been previous interventional trials with statins, which failed. We need to understand why our results are different. Could there be a group of patients who does benefit from statin treatment?”

“Our study was a cohort study, exploratory and does not attempt to establish a causal relationship between statin treatment and cognitive outcomes,” she added. “There may be some confounding factor that explains our results. However, cohort studies with the right design can sometimes attempt causal inference: conducting such a study would be a useful final step before an interventional trial.”

Statins lower lipids, which helps improve the overall lipid biochemical profile.

They work by decreasing levels of low-density lipoprotein (LDL, aka “bad” cholesterol) and increasing levels of the high-density lipoprotein (HDL, aka “good” cholesterol).

“Through this process and other mechanisms (such as cholesterol plaque stabilization in arteries and improving arterial wall integrity), statins help with primary and secondary prevention of cardiovascular and cerebrovascular disease,” said Dr. Mike Gorenchtein, a geriatric specialist at Northwell Lenox Hill Hospital in New York who was not involved in the study.

Dysregulation of the brain cholesterol hemeostasis may be similarly implicated in the development of Alzheimer’s disease or vascular dementia (due to impaired cerebral circulation) through cholesterol-specific pathways and neurodegenerative processes (such as changes in oxidative stress and the amyloidogenic Aβ pathway), Gorenchtein explained.

Statin therapy is therefore also postulated to have beneficial effects on cognition, especially in Alzheimer’s disease and mixed dementia (a combination of Alzheimer’s disease and vascular dementia), he added.

Some of the direct cognitive beneficial effects of statin therapy may include protection against tau protein hyperphosphorylation (in Alzheimer’s disease, tau protein becomes hyperphosphorylated and aggregates to form toxic neurofibrillary tangles within brain cells) and mediation of the brain cholesterol homeostasis,” Gorenchtein told Healthline.

“Since statin therapy improves the management of chronic conditions, such as pre-existing cerebrovascular disease and coronary artery disease, this, in turn, may have an indirect positive effect on overall health and subsequently on cognition itself,” he added.

Statin therapy may be more beneficial in certain people with Alzheimer’s dementia.

“Such patients may be the ones who have mixed Alzheimer’s and vascular dementia (likely due to improvement of the cerebrovascular disease component),” said Gorenchtein. “Similarly, patients with Alzheimer’s disease and co-existing conditions such as hyperlipidemia (present in all the patients in this study), coronary heart disease (atherosclerotic plaque impairing blood flow to the heart) or carotid artery disease (atherosclerotic plaque impairing blood flow to the brain) may gain multiple health benefits from statin therapy.”

Gorenchtein noted that statins may also be appropriate as a prevention for some people who don’t have dementia.

“In medical practice, such patients may have been placed on statins without having hyperlipidemia, coronary artery disease, cerebrovascular disease, or significant family history of early onset heart disease with the goal of primary disease prevention. This is similar to how low-dose aspirin may be prescribed to patients for many years to reduce the risk of heart attack and stroke,” Gorenchtein explained.

Lastly, while some results of this study are statistically significant, it is important to also consider whether these results are clinically significant. For instance, a mild improvement in the cognitive score by less than 1 point (such as noted in the current study) may not necessarily correlate with noticeably better cognition or daily functioning, Gorenchtein concluded.