A Ray of Hope for Dementia Prevention! Could Cholesterol Medication Also Protect the Brain? Insights from a Study of 130,000 People on the Relationship with Dementia Risk

"Cholesterol medication is taken to protect the heart and blood vessels." This familiar treatment might also be related to future dementia.

A study from Denmark, introduced by the German newspaper WELT, indicated that those who started statins early after being diagnosed with type 2 diabetes had a lower risk of dementia.

It's important to note that this is not about new, expensive drugs. The focus is on medications used in everyday medical practice and the timing of starting treatment.

However, it's premature to conclude that "taking it can prevent dementia." It's necessary to distinguish between the possibilities shown by this study and the aspects that remain unknown.

Examining records of over 130,000 people and comparing the timing of treatment initiation

The research team extracted data from Denmark's national registry of 132,585 people who developed type 2 diabetes between 2006 and 2019 and had not used statins. The follow-up continued until the end of 2021 at the latest.

The comparison involved three treatment strategies: not starting statins within five years after diagnosis, starting within one year of diagnosis, and starting between one and five years after diagnosis.

The study used statistical methods aiming to approximate a randomized trial as closely as possible, using actual medical records. The median follow-up period was 7.1 years, during which dementia was confirmed in 3,592 people.

The results showed that, compared to not starting statins, early initiation reduced the relative risk of dementia over ten years by 15%, and even late initiation reduced it by 10%. This study does not claim to have improved symptoms of already developed dementia.

Seeing "15% lower" in actual numbers

Relative risk alone makes it difficult to grasp the magnitude of the difference. The adjusted ten-year estimated risks shown in the abstract of the paper are as follows:

The absolute difference between early initiation and no initiation is 0.59 percentage points in finer numbers, equivalent to a difference of about 6 people per 1,000.

"15% reduction" does not mean that 15 out of 100 people will avoid dementia. Furthermore, this conversion to numbers does not represent the exact number of people that can be prevented by the medication. It is merely an estimated difference based on observational data.

To avoid overestimating or underestimating the numbers, it is essential to view "how much percentage decreased" and "what the original percentage was" together.

Why cholesterol and the brain are connected

Statins are drugs that suppress cholesterol synthesis in the liver and lower LDL cholesterol. Their role in preventing heart attacks and strokes is well established, separate from their effects on dementia.

The brain receives oxygen and nutrients from blood vessels. Maintaining vascular health is not unrelated to considering brain health.

The 2024 Lancet Dementia Commission report added high LDL cholesterol in middle age as a modifiable risk factor for dementia. It estimates that addressing 14 factors, including diabetes, hypertension, smoking, lack of exercise, hearing loss, and social isolation, could prevent or delay about 45% of dementia cases worldwide.

However, this is a theoretical estimate for the entire population and does not mean that individual efforts can always prevent it. It is not a basis for blaming the lifestyle of those who have developed dementia.

Even with expectations, "preventive effect confirmed" cannot be stated

A significant remaining issue in this study is that the differences between those who receive treatment and those who do not cannot be completely eliminated.

For example, people who start treatment early may find it easier to continue visiting the hospital and taking medication and may also be engaged in other health management activities. Conversely, some people may find it difficult to be prescribed medication due to chronic conditions or health status. Even with statistical adjustments, unrecorded differences may still affect the results.

Past studies have not uniformly pointed in one direction. A 2016 Cochrane review examined two randomized trials involving a total of 26,340 people and reported that no preventive effect of statins on dementia was demonstrated.

The subjects, initiation timing, and research methods differ between those results and this study. Neither can new possibilities be denied based solely on older trials, nor can preventive effects be confirmed based solely on this observational study.

What is needed is further research to confirm who benefits, when to start, and how much benefit there is.

Sharing on social media and reader reactions—concerns about side effects

Posts introducing this study can also be found in the science community on the overseas forum Reddit. The point that "people who started statins early after being diagnosed with type 2 diabetes may have a lower risk of dementia" is being shared. However, it is not possible to determine the general user comments' pros and cons or their spread from the public display that could be confirmed.

On the other hand, specific opinions were posted in the reader comment section of the WELT article provided. The following is a summary of the reactions seen in that comment section, not the overall trend on social media.

One prominent issue is the concern about side effects. There were posts about experiencing muscle discomfort and posts about feeling fatigue or cognitive changes while a family member was on medication.

Another reader supported drug treatment as a measure against vascular disorders. In response to a post questioning why dementia patients are increasing despite the widespread use of medication, there was a reply pointing out the impact of aging.

What can be seen from these exchanges is that research results alone do not alleviate patients' concerns. Precisely because it is a medication taken daily, people want to consider its effects and burdens in the context of their own lives.

However, causal relationships between medication and symptoms cannot be determined based solely on personal experiences. The UK's Alzheimer's Research UK also explains that there is no strong evidence that statins increase the risk of dementia. Balancing not dismissing personal discomfort and not definitively stating general risks is possible.

In Japan, consider health check results beyond just "blood sugar levels"

For Japanese readers, this study can serve as an opportunity to review health check results and regular diabetes check-ups.

When concerned about blood sugar levels or HbA1c, are LDL cholesterol and blood pressure checks being postponed? During consultations, it is essential to confirm "why am I taking this medication" and "what is the treatment goal."

The Japan Atherosclerosis Society explains that the evidence for the effectiveness of statins in lowering LDL and preventing atherosclerotic diseases is well established. On the other hand, it also calls for attention to side effects such as muscle pain and the risk of new-onset diabetes.

This study targets individuals who have already developed type 2 diabetes. It is necessary to evaluate the benefits and drawbacks for each individual without confusing it with another issue, such as the "possibility of new diabetes onset due to statins."

If there is discomfort, communicate when it started and what symptoms are present to a doctor or pharmacist. This may lead to adjustments in the type or amount of medication or consideration of alternative treatments. It is advisable to avoid starting or stopping medication based on self-judgment after seeing the news.

The discovery regarding statins and dementia in this study is promising. However, what is certainly useful at this point is not seeking medication out of fear of dementia, but understanding the necessary vascular treatment for oneself and continuing it with confidence.

Do not dismiss the numbers pointed out during health check-ups as a problem only for that year. This attitude will be the starting point for considering the future of the heart and brain.

Source URL

1. WELT:
   https://www.welt.de/gesundheit/article6a96e25ad32756d4be19ba5b/demenz-cholesterin-senker-koennten-das-risiko-deutlich-reduzieren.html

2. Danish Capital Region Research Portal: Bibliography and abstract of the original paper. Research subjects, ten-year absolute risk, relative risk, and study limitations.
   https://research.regionh.dk/en/publications/association-between-timing-of-statin-treatment-after-diabetes-dia/
   Original paper DOI:https://doi.org/10.1016/j.lanepe.2026.101814

3. European Society of Cardiology (ESC): Official commentary on the research presentation. Comparison of initiation timing, research methods, and cautions as an observational study.
   https://www.escardio.org/news/press/press-releases/statins-are-associated-with-a-lower-risk-of-dementia-in-patients-with-type-2-diabetes/

4. UCL: Explanation of the 2024 Lancet Dementia Commission report. 14 modifiable risk factors and estimates of prevention and delayed onset.
   https://www.ucl.ac.uk/news/2024/jul/nearly-half-dementia-cases-could-be-prevented-or-delayed-tackling-14-risk-factors

5. Cochrane: Confirmation that the preventive effect of statins on dementia was not demonstrated in randomized trials in 2016.
   https://www.cochrane.org/ja/evidence/CD003160_statins-prevention-dementia

6. Reddit r/science: Shared post introducing this study. Not representative of the overall response or pros and cons on social media.
   https://www.reddit.com/r/science/comments/1w90pwk/people_with_type_2_diabetes_who_start/

7. Alzheimer’s Research UK: Explanation of the relationship between cholesterol, statins, and dementia, and the lack of strong evidence supporting increased dementia risk.
   https://www.alzheimersresearchuk.org/news/cholesterol-statins-and-dementia-whats-the-link/

8. Japan Atherosclerosis Society "Q&A on Dyslipidemia Treatment": Effectiveness of statins, side effects, diabetes onset risk, and shared decision-making with patients.
   https://www.j-athero.org/jp/publications/si_qanda/