嗅覺喪失可能是阿茲海默症的早期徵兆
Loss of smell may be an early sign of Alzheimer's disease
最近的研究顯示，嗅覺的細微喪失可能是阿茲海默症的早期警示訊號。
Recent research suggests that a subtle loss of smell might be an early warning sign of Alzheimer's disease.
雖然我們常將阿茲海默症與記憶力衰退聯繫在一起，但醫生發現嗅覺功能障礙往往在認知能力明顯下降的數年前就已出現。
While we often associate Alzheimer's with memory loss, doctors have found that olfactory dysfunction often appears years before cognitive decline becomes obvious.
這通常並非指完全喪失嗅覺，而是辨識或區分不同氣味的能力下降。
This does not usually mean a total loss of smell, but rather a decreased ability to identify or distinguish between different odors.
科學家認為這是因為澱粉樣蛋白等毒性蛋白質堆積在嗅球和內嗅皮質所致，這些大腦區域對嗅覺和記憶力至關重要，且在影響其他區域前便已受損。
Scientists believe this happens because toxic proteins like amyloid-beta accumulate in the olfactory bulb and entorhinal cortex, areas of the brain critical for both smell and memory, long before they affect other regions.
雖然老化、病毒感染或帕金森氏症等狀況也會導致嗅覺喪失，但像賓夕法尼亞大學嗅覺鑑定測試等臨床工具正成為風險篩查的利器。
While conditions like aging, viral infections, or Parkinson’s disease can also cause smell loss, clinical tools like the University of Pennsylvania Smell Identification Test (UPSIT) are becoming valuable for risk screening.
必須記住的是，嗅覺減退並非確診的絕對標準，它僅是龐大診斷拼圖中的一塊。
It is important to remember that a diminished sense of smell is not a definitive diagnosis; it is simply one piece of a larger diagnostic puzzle.
