The updated dementia prevention report from The Lancet, a top global medical journal, in 2025 reveals that by managing 18 modifiable risk factors, the risk of dementia can be reduced by 65%.
Among these 18 major risk factors, there is one indicator that deserves high vigilance from everyone - "high levels of low-density lipoprotein cholesterol", also known as "bad cholesterol" (LDL-C). It is the core ingredient for the formation of "plaques" in our blood vessels.
1
Why is carotid plaque the "alarm" for the brain?
Imagine the carotid artery as the "lifeline" supplying blood to the brain. Plaque is the "garbage" (mainly composed of fat, cholesterol, and calcium) that gradually accumulates on the inner wall of this lifeline.
Its existence poses a threat to our brain from two aspects:
Firstly, there is direct physical obstruction. The enlargement of plaques can lead to vascular stenosis, akin to the buildup of scale in a water pipe, reducing blood flow. This can cause chronic cerebral blood insufficiency, potentially leading to dizziness, decreased concentration, and slowed thinking. If this persists over a long period, it can accelerate the aging and functional decline of brain tissue.
More importantly, it serves as a clear "risk mirror". The appearance of carotid plaque is a clear signal from your body, indicating that the systemic process of "atherosclerosis" has already occurred in your body. This process shares the same root and origin with many dementia risk factors listed in the Lancet report.
A brain imaging study published in the Journal of the American College of Cardiology (JACC) in 2021 provided direct radiographic evidence for this association. The study conducted brain PET metabolic scans on over 500 middle-aged individuals, with an average age of 50, who exhibited no symptoms but had detected carotid plaques.
It turns out that:
The amount of carotid plaque is inversely proportional to the level of whole-brain glucose metabolism. The heavier the plaque burden, the lower the overall "vitality" of the brain.
This association is independent. Even after considering and excluding the influence of all traditional cardiovascular risk factors such as hypertension and hyperlipidemia, carotid plaque itself is still significantly associated with cerebral hypometabolism.
The most profoundly affected brain regions are "significant": the areas with the most pronounced metabolic decline are concentrated in the parietal lobe, temporal lobe (angular gyrus, supramarginal gyrus), and cingulate gyrus - these regions are precisely the "hardest-hit areas" where metabolic abnormalities and functional decline first emerge in the early stages of Alzheimer's disease.
This implies that plaques on the carotid artery may have already begun to exert a subtle negative impact on our key brain regions closely related to memory and cognition during middle age.
2
Plaques and dementia share a common "dangerous recipe"
Where does your carotid plaque come from? The answer lies in that authoritative "risk factor list". Its formation is the result of the combined effects of multiple risk factors:
Excess "raw material": Excessively high "bad cholesterol" (LDL-C) in the blood is the cornerstone for plaque formation. It is identified as an independent risk factor for dementia (accounting for 7%) in the Lancet report, and its importance is self-evident.
"Destructive force" comes first: hypertension is like a continuous high-pressure water flow, impacting and damaging the smooth inner lining of blood vessels, opening up "gaps" for cholesterol deposition. The aforementioned JACC study further points out that among numerous risk factors, hypertension is the most strongly and independently associated modifiable factor with low brain metabolism. Its "blow" to key areas such as the cingulate gyrus of the brain is particularly prominent.
"Accelerator" Promotion: Toxins from smoking directly attack the vascular endothelium; lack of physical exercise slows down metabolism, making lipids prone to deposition; obesity often accompanies systemic chronic inflammation, "adding fuel to the fire" for vascular damage.
The "tipping point" lurks: unstable plaques may rupture, instantly forming a blood clot that obstructs cerebral blood vessels, leading to cerebral infarction (stroke). This is the most direct blow to cognitive function.
It can be seen that these factors that promote carotid plaque formation, including hypertension, high cholesterol, diabetes, smoking, obesity, and lack of exercise, are also the common "soil" that nourishes the risk of Alzheimer's disease. Plaque is the "visual evidence" left on the blood vessels by these unhealthy lifestyles, and the latest scientific imaging tells us that it is also an early warning signal for brain metabolic health.
3
Action guide: Turn risk warnings into opportunities to protect your brain
The discovery of carotid plaque should not cause excessive anxiety, but it must not be ignored. It should serve as a clear signal to initiate active management.
Firstly, it is recommended to conduct a clear assessment. For individuals over 40, especially those with "three highs" (high blood pressure, high blood sugar, and high cholesterol), a history of smoking, a family history of cardiovascular disease, or subjective memory decline, carotid artery ultrasound is a non-invasive, economical, and efficient screening method of choice. It can clearly reveal the size, location, and stability of plaques, providing crucial evidence for subsequent decision-making.
Based on this, we should carry out targeted source management. This requires us to directly benchmark the list of modifiable risks in the Lancet report:
Strictly control "bad cholesterol": Under the guidance of a doctor, reduce LDL-C to the desired range through lifestyle intervention and necessary medication (such as statins). These medications not only lower blood lipids but also help stabilize plaques and prevent them from rupturing.
Maintain stable blood pressure and blood glucose levels: follow the doctor's advice to take medication regularly and monitor your condition, ensuring they are consistently maintained at optimal levels over the long term.
Resolutely and thoroughly quit smoking: The benefits of quitting smoking to blood vessels begin to accumulate from the very first day.
Get your body moving regularly: Engaging in moderate-intensity aerobic exercise, such as brisk walking, swimming, or cycling, for at least 150 minutes per week can effectively improve metabolism and reduce inflammation.
Optimize the dietary structure on the dining table: Draw more inspiration from the "Mediterranean diet" pattern, increase the intake of vegetables, fruits, whole grains, and fish (especially deep-sea fish), use healthy fats such as olive oil, while strictly limiting saturated fats (such as fatty meat and animal organs) and trans fats (such as fried foods, pastries, and milk tea).
Furthermore, we should take a rational view of dietary supplements. Many friends are concerned about whether taking supplements can protect blood vessels and the brain. Currently, although some observational studies suggest that specific nutrients may be beneficial, if considering taking supplements, it is essential to follow one principle: they cannot replace the cornerstones of treatment and lifestyle adjustments mentioned above.
Lastly, seek "treatment for both the heart and brain" in medical care. If you or your family members have cognitive difficulties, you can proactively communicate with your doctor about your vascular health during follow-up visits to the memory clinic.
Hainan Chengmei Hospital's Memory Clinic integrates professional resources from multiple fields to provide patients with comprehensive, precise, and personalized diagnosis and treatment services.
Expert Introduction
Dai Wenxin, Chief Physician
Executive Director of the Multidisciplinary Geriatrics Diagnosis and Treatment Center
Professor, doctoral candidate
Postdoctoral researcher, master's supervisor
Medical expertise:
I. Diagnosis and treatment of Alzheimer's disease and other geriatric diseases
II. Diagnosis and treatment of diseases across multiple disciplines, including respiratory system, cardiovascular system, nervous system, and geriatric diseases
III. Genetic diagnosis, chemotherapy, targeted therapy, immunotherapy, microenvironment analysis, and integrated precision treatment of tumors
IV. Genetic diagnosis and precision treatment of hypertension, hyperlipidemia, hyperuricemia, and hyperglycemia
V. New biomedical technologies such as stem cell and gene programming, as well as new technologies like insulin pumps and diabetes reversal
VI. High-intensity focused ultrasound (HIFU) therapy for benign and malignant tumors
VII. Microbial therapy of intestinal flora for chronic diseases and mental and psychological disorders
VIII. Diagnostic and therapeutic techniques under medical endoscopes such as bronchoscope, mediastinoscope, and thoracoscope
IX. Sleep Medicine
X. Chronic disease management
Clinic Hours: Monday and Wednesday morning
Source | WeChat official account of Professor Han Ying's team at Xuanwu Hospital