名單上的第一位候選人,你可能並不陌生。如果你的家族中有人罹患第二型糖尿病,十之八九都聽過、甚至吃過這顆藥:二甲雙胍(Metformin)。它是一顆歷史悠久、價格低廉、在藥局極為常見的「老藥」。但就是這顆看似平凡無奇的降血糖藥,現在卻搖身一變,站上了全球抗老研究舞台的 C 位。一顆用來控制血糖的藥物,究竟是如何跨界成為抗老明星的呢?
為了解答這個問題,美國醫學界目前正在推動一個極具野心的計畫,名為 TAME(Targeting Aging with Metformin)的大型雙盲臨床試驗。這個試驗的獨特之處在於,它是有史以來第一個試圖讓美國食品藥物管理局(FDA)承認「衰老本身」可以作為藥物適應症的試驗。過去 FDA 只核准藥物用來治療「特定疾病」,如果 TAME 試驗成功,這將徹底顛覆現代醫學的法規與常識,成為醫學史上的重大里程碑。不過,如果二甲雙胍是屬於溫和防守派,醫學界是否還有更具攻擊性的王牌?
而 AI 的加入,更是徹底改變了抗老藥物的研發遊戲規則。過去找藥就像是「大海撈針」,科學家必須把成千上萬種化合物一種一種拿來測試,耗時數十年。現在,AI 正在把藥物開發變成一門「精準計算」的科學——強大的演算法可以在短時間內篩選數百萬種分子的 3D 結構,預測它們與人體抗老標靶結合的機率,直接在伺服器裡把長壽藥「算」出來。科學正在以我們難以想像的速度,把「長壽」從一種中彩券般的基因運氣,變成一種可以被精準管理的人體工程。然而,當科學的突破即將實現,我們是不是又將面臨一個嶄新的社會問題?
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此外,聽損與否也可能會影響一個人大腦的結構與功能。美國約翰霍普金斯大學的研究人員 [10],利用「巴的摩爾老化長期研究(Baltimore Longitudinal Study of Aging)」的資料,針對聽損與腦容量的關係進行了一項有趣的研究,他們分析了一群受試者在逐漸老化時,其腦容量的變化。受試者在研究之初,做了聽力評估,接著接受為期長達十年、每年一次的核磁共振檢查。結果顯示,研究開始時就患有聽損的受試者,相較於聽常者,其大腦有較大幅度的萎縮,平均以每年一立方釐米以上的速度流失大腦組織,而這些大腦組織恰好與輕度認知功能退化和早期失智症所表現出的記憶衰退的行為有關 [11]。
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