[100-Year Brain Health①] 3 out of 10 Elderly Aged 80 and Above Have Dementia

820,000 Dementia Patients... 7th Leading Cause of Death
Various Types Including Alzheimer’s and Vascular Dementia

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[Asia Economy Reporter Kim Young-won] 'What was I trying to take out?'

One day, while opening the refrigerator door to have a meal, Ms. Kim Jeong-sook (a pseudonym) had to close the refrigerator door empty-handed. Although she opened the door, she simply could not remember what she was supposed to take out. At first, she dismissed it as forgetfulness, but as this happened repeatedly, her anxiety grew. Led by her daughter, Ms. Kim underwent tests at a large general hospital and was diagnosed with dementia.

With advances in medical technology extending average life expectancy, it has become more important to 'age healthily' rather than just 'live longer.' Among these concerns, the greatest fear for the elderly is dementia. This is because not only do they lose their memory, but they also find it difficult to manage daily life independently, requiring help from children or others around them. Dementia is a representative brain disease experienced by the elderly, commonly occurring in Korea, where 3 out of 10 people aged 80 or older suffer from it. Korea is on the verge of entering a super-aged society in 2025, with over 20% of the population aged 65 or older, so the number of dementia patients is expected to increase further. Experts point out that the most common Alzheimer's-type dementia has no clearly identified cause and is incurable, making prevention the most important strategy.

820,000 Elderly Dementia Patients... 7th Leading Cause of Death

According to the National Health Insurance Service on the 26th, the number of dementia patients aged 65 or older in 2020 was 829,227, accounting for 10.2% of this age group. Narrowing down to those aged 80 or older, among a total of 1,895,712 people, 28.3% (536,708) were dementia patients. The number of elderly dementia patients is expected to continue rising, reaching 3.02 million by 2050. The estimated proportion relative to the elderly population will be about 15.9%.

In particular, female dementia patients outnumber male patients by 2.5 times. In 2020, women accounted for 71.2% (648,783) of dementia patients nationwide, while men accounted for 28.8% (262,746). This means that 7 out of 10 dementia patients in Korea are women. Although the exact cause is not scientifically established, experts speculate that one reason is women's longer life expectancy compared to men. In Korea, the life expectancy for women is about 6 years longer than for men, at 86.5 years.

It is premature to feel reassured just because one has not been diagnosed with dementia. Mild cognitive impairment (MCI), considered a precursor stage to dementia, may progress. As of 2020, 134,227 patients with MCI were registered in the Ministry of Health and Welfare's Dementia Safety Integrated Management System (ANSYS). MCI often appears as 'amnestic mild cognitive impairment,' where memory impairment occurs but daily life can still be maintained. According to the Korean Dementia Association, 1-2% of normal individuals progress to dementia annually, but about 10-15% of patients with amnestic MCI progress to Alzheimer's-type dementia.

Recently, cases where dementia leads to death have also increased. According to Statistics Korea, the dementia mortality rate per 100,000 people rose from 11.8 in 2009 to 16.9 in 2013 and 20.7 in 2020. Alzheimer's disease ranks as the 7th leading cause of death in Korea. In the global ranking of causes of death published by the World Health Organization (WHO), Alzheimer's and other dementias also rank 7th.

Not All Dementia Is the Same

Although dementia is commonly referred to as a single condition, there are various types. The main types include Alzheimer's-type dementia, vascular dementia, and the commonly known alcohol-related dementia. Among these, Alzheimer's-type dementia is the most prevalent. According to data from the Central Dementia Center, as of 2020, 75.5% of estimated dementia patients aged 65 or older had Alzheimer's-type dementia. Alzheimer's disease, the underlying condition, is a disorder in which brain cells degenerate, gradually impairing cognitive functions such as memory. It is named after the German doctor Alois Alzheimer, who first discovered the disease in 1907.

However, the exact cause of Alzheimer's disease remains unclear. The brains of Alzheimer's patients are smaller than those of healthy individuals, and microscopic examination of brain tissue reveals amyloid-beta protein deposits forming senile plaques and tau protein tangles creating neurofibrillary tangles. Experts believe these characteristics lead to nerve cell death and the onset of Alzheimer's, but the cause of these phenomena has not been identified.

The second most common type, vascular dementia, accounts for about 8.6% of all dementia cases. It is caused by problems with blood supply to the brain, with cerebrovascular disease as the underlying cause. Symptoms and progression vary depending on the type, size, and location of the cerebrovascular disease. Other types include alcohol-related dementia caused by habitual drinking, Lewy body dementia, and frontotemporal dementia.

Treatment varies depending on the type of dementia. Professor Choi Seong-hye of Inha University Hospital's Neurology Department explained, "There are dozens of causes of dementia, with Alzheimer's being the most common. For Alzheimer's, there are still limitations in completely stopping progression, making treatment difficult." On the other hand, vascular dementia can be treated by addressing the underlying disease. Professor Choi said, "If recurrence of stroke such as cerebral hemorrhage or cerebral infarction is prevented, progression can be halted. Because Alzheimer's disease, which is difficult to treat, accounts for most dementia cases, there is a common misconception that all dementia is hard to treat."

Approaching 140 Million in 28 Years

The increase in dementia patients is not just a domestic issue. The World Health Organization (WHO) estimated last year that about 55 million people worldwide suffer from dementia due to brain-related diseases. The WHO report projects that by 2030, the number of dementia patients will increase by 40% to 78 million, and by 2050, it will reach 139 million.

Dr. Maria Carrillo, Chief Science Officer of the Alzheimer's Association, stated at last year's Alzheimer's Association International Conference (AAIC), "Although dementia incidence has recently decreased due to expanded educational access in developed and other regions, increased attention to heart health, and lifestyle improvements, the total number of dementia patients continues to rise due to population aging. Young people are also rapidly increasing in obesity, diabetes, and sedentary behavior, all of which are risk factors for dementia."

Particularly, low-income countries face challenges in adequately responding to dementia despite high prevalence rates. The WHO pointed out that over 60% of the world's dementia patients live in low- and middle-income countries, but most countries reporting provision of community-based dementia services are high-income countries. Low-income countries tend to rely more on informal home care rather than utilizing caregiving and other support services compared to high-income countries.