About one in 10 people aged 65 or older has dementia, while nearly three in 10 are in a state of mild cognitive impairment, often called the pre-dementia stage. Among those with mild cognitive impairment, 10 to 15 percent progress to dementia each year. Beta-amyloid, considered the primary causative substance behind mild cognitive impairment and dementia, begins to slowly accumulate in the brain before symptoms such as memory decline appear. For this reason, experts stress the importance of practicing dementia-preventing lifestyle habits from an early stage.
Recently, treatments that slow the progression of dementia by removing beta-amyloid or suppressing its accumulation during the mild cognitive impairment or early dementia stages have also drawn attention. Yang Young-soon, professor of neurology at Soonchunhyang University Cheonan Hospital, who appeared on Seoul Economic Daily TV's "Master Doctor Now" at 9 p.m. Thursday, said, "Beta-amyloid can begin accumulating 15 to 20 years before dementia manifests," adding, "This means that managing it early creates an opportunity to prevent dementia 20 years later."
◇ Mild Cognitive Impairment Progresses to Dementia at 10-15% Annually
Not all cases of mild cognitive impairment progress to dementia. However, in cases of mild cognitive impairment that lead to Alzheimer's disease, about 10 to 15 percent are known to progress to dementia each year. In particular, the likelihood of progression to dementia is high when memory decline is the main symptom and is accompanied by decline in visuospatial ability or personality changes, or when abnormal findings appear in brain imaging tests such as MRI. Caution is also needed for those with a family history or who carry APOE4, an APOE gene variant associated with dementia risk.
Diagnosis involves taking a medical history, blood tests, brain MRI and CT scans, and neuropsychological testing. Blood tests are necessary to identify causes that can produce symptoms similar to dementia, such as thyroid dysfunction, vitamin deficiency, and depression. To examine more precisely whether Alzheimer's disease is present, amyloid PET scans are used. Recently, biomarker tests that detect amyloid or tau proteins through blood have also been advancing, and the market for early dementia diagnosis is expected to grow in the future.
Professor Yang cited beta-amyloid as one of the key causes of dementia. While amyloid itself is a normal protein, it becomes beta-amyloid—which does not dissolve and accumulates in the brain—after undergoing an abnormal breakdown process. This beta-amyloid acts as a toxic protein that damages brain cells. Beta-amyloid accumulates from 15 to 20 years before symptoms appear, gradually causing the brain to atrophy.
◇ New Drugs and Ginkgo Leaf Extract That Reduce Beta-Amyloid Draw Attention
Lecanemab, a recently noted Alzheimer's treatment, is a monoclonal antibody therapy that binds to beta-amyloid aggregates and helps remove them. However, it is not a drug that can be used for all patients. It can only be used during the mild cognitive impairment or early dementia stages, and its effects are limited in dementia beyond the mid-stage. In addition, there is a risk of side effects called "ARIA," such as brain edema or brain hemorrhage, so whether the drug can be administered must be carefully determined through tests such as MRI.
Professor Yang also introduced the potential of ginkgo leaf extract at the mild cognitive impairment stage. He conducted a study comparing, over 18 months, a group of mild cognitive impairment patients who tested positive on amyloid PET scans and took ginkgo leaf extract against a group that took other medications such as omega-3 and choline precursors. As a result, no patients in the ginkgo leaf extract group progressed to dementia, while about 28 percent in the comparison group progressed to dementia.
In addition, while the ginkgo leaf extract group's amyloid PET levels did not increase further but were maintained, the comparison group showed a tendency toward increased amyloid deposition. Professor Yang explained, "There is a possibility that ginkgo leaf extract suppressed the process by which beta-amyloid develops into plaques, thereby helping to maintain the mild cognitive impairment state."
However, caution is needed against taking ginkgo leaf extract arbitrarily like a health functional food. Professor Yang said, "Low-dose ginkgo leaf extract is mainly used to improve blood circulation, and cognitive improvement effects have been reported in high-dose regimens of 200 mg or more," adding, "Because food and pharmaceuticals differ in approval standards and quality control, if cognitive decline is suspected, consulting a specialist should come first."
◇ Use Your Head, Meet People, Sleep Deeply
Lifestyle management is also important. Professor Yang presented aerobic exercise, a Mediterranean diet, sufficient sleep, social activity, and cerebral activity as key to dementia prevention. In particular, during deep sleep, the glymphatic system, which expels waste products from the brain, operates and can help remove waste products such as beta-amyloid.
Activities that engage the brain also help prevent dementia. Learning a new language, writing, and activities that use the hands extensively stimulate the brain overall. Social activities such as meeting people, conversing, and laughing are also positive for maintaining cognitive function.
Conversely, smoking, excessive drinking, chronic conditions such as high blood pressure, diabetes, and hyperlipidemia, and stress can increase dementia risk. Stress hormones can atrophy the hippocampus, which is responsible for memory, accelerating cognitive decline.
The role of the family is also important. If parents repeat the same questions, cannot remember even when given hints, and are accompanied by difficulty finding their way, personality changes, or abnormal behavior such as suspicion or aggression, it is advisable to seek medical care. However, attitudes of scolding or forcibly correcting them for repeating memory mistakes should be avoided.
Professor Yang urged, "Dementia is not a problem for the patient alone but a disease that affects caregivers and the entire family," adding, "Rather than trying to bear it alone, it is important for families to actively use national support systems such as dementia care centers."
"It's Not Forgetfulness": The First Warning Signs Dementia Patients Show [Yang Young-soon, Professor of Neurology, Soonchunhyang University Cheonan Hospital]
