Can I be free of dementia?

Home > Opinion > Columns

Can I be free of dementia?

Published: 18 Aug. 2025, 00:05

Audio report: written by reporters, read by AI

Park Eun-jung

The author is a professor at Kyung Hee University School of Medicine

If someone were to ask me what disease I fear the most, I would, without hesitation, answer “dementia.” For 14 long years, I watched my father-in-law struggle against it — stripped, against his will, of even the bare minimum of human dignity. When his cognitive function briefly returned, the psychological pain and terror he must have felt are beyond words — and he wasn't alone in his suffering. My family’s freedom was sharply curtailed by the demands of caregiving, and the endless financial burden hung over us like a bomb that could explode at any time.

A global crisis: One case every three seconds

Dementia is caused by damage to brain cells, leading to a decline in cognitive function and changes in personality. It can impair behavior and motor skills as well. Sixty to 70 percent of patients suffer from Alzheimer’s-type dementia, while Parkinson’s disease and vascular conditions are also major causes. Yet, the root mechanisms remain unclear.

The World Health Organization reported last year that 10 million new cases of dementia are recorded annually — roughly one every three seconds. What, then, can be done to prevent it? A 2021 study in Nature Medicine by Ron Sender and Ron Milo of Israel’s Weizmann Institute of Science estimated that of the body’s 30 trillion cells, some 330 billion are replaced every day — including 86 percent of blood cells and 12 percent of intestinal cells. But brain neurons and lens cells never regenerate. Prevention, therefore, hinges on blocking damage to brain cells. That requires a deeper understanding of how such damage occurs.

People are seen at a hospital for Alzheimer's disease patients in Seoul on April 4, 2024. [YONHAP]

Cells are harmed in two main ways. The first is direct injury from toxic substances, with severity determined by exposure and dose — as in deaths caused by inhaling toxic gases during a fire. The second is indirect damage from deprivation of essential inputs for survival, such as oxygen. Hypoxia from sepsis or carbon monoxide poisoning is a prime example. Though the brain accounts for only about 2 percent of body weight, it consumes 20 percent of the body’s oxygen and energy. When blood supply is impaired, the brain is the first organ to suffer.

Memory loss due to dementia. Senior woman losing parts of head feeling confused as symbol of decreased mind function. [shutterstock]

Recent findings add new dangers. An analysis of brain, liver and kidney tissues from people who died in 2016 and 2024 found microplastics in the brain at up to 30 times higher levels than in other organs — and as much as five times more in dementia patients than in healthy individuals. These particles were observed mainly in blood vessel walls and immune cells. While microplastics are unlikely to damage neurons directly, their accumulation in cerebral vessels may obstruct blood flow and harm brain cells. Fine dust, too, has emerged as a potential dementia trigger, either through toxic water-soluble components or by weakening lung function when insoluble particles accumulate in alveoli, reducing oxygen exchange.

Air is not the only culprit. A Chinese study in 2024 found that elderly people who frequently used household products like mouthwashes, air fresheners, disinfectants and deodorizers scored lower on cognitive tests, suggesting that everyday chemicals may induce or worsen dementia.

Why 99.6 percent of trials fail

The disease was first identified in 1901 by German neurologist Alois Alzheimer, who observed memory loss in a female patient and, after her death, found cortical atrophy, plaque, neurofibrillary tangles and vascular changes in her brain. His 1907 paper gave rise to the “amyloid hypothesis”: that abnormal proteins like beta-amyloid and tau gradually accumulate and kill brain cells. Since then, pharmaceutical companies worldwide have poured immense resources into drugs targeting these proteins. But 99.6 percent of clinical trials have failed, and the once-dominant hypothesis is now under doubt. It is time to confront the deeper reasons for such repeated failures.

Dementia is the quintessential disease of old age. The challenge is to detect changes in the brain before diagnosis and slow the disease’s progression. That requires interdisciplinary collaboration to establish causal links between environmental exposure and the onset of dementia. Sound scientific decisions on data elements and the acquisition of high-quality data will be decisive weapons in the global race for medical AI.

An older person walks by Nagwon Arcade in Jongno District, central Seoul, on July 29. [YONHAP]

For Korea, which is entering a super-aged society faster than any other nation, addressing dementia and other geriatric diseases is not a choice but a necessity. The government must act swiftly — reducing citizens’ exposure to environmental risks, ensuring transparency from companies about product ingredients and offering incentives to encourage voluntary corporate participation. Laws and regulations matter, but nothing is stronger than motivation that drives voluntary action.

This article was originally written in Korean and translated by a bilingual reporter with the help of generative AI tools. It was then edited by a native English-speaking editor. All AI-assisted translations are reviewed and refined by our newsroom.