長壽的秘訣是什麼？
均衡的營養嗎？對，均衡的營養很重要。但是，更重要的是，運動。
“As the authors of the JAMA study concluded, “Cardiorespiratory fitness is inversely associated with long-term mortality with no observed upper limit of benefit [emphasis mine]. Extremely high aerobic fitness was associated with the greatest survival.”*
JAMA研究者下了一個終極的結論：心肺功能強健的程度和長期的死亡率成反比，而且心肺功能強健的好處並沒有上限。愈高的有氧健身，和活得愈久密切相關。
“…A 2018 study in JAMA that followed more than 120,000 people found that higher VO, max (measured via a treadmill test) was associated with lower mortality across the board. The fittest people had the lowest mortality rates —by a surprising margin. Consider this: A person who smokes has a 40 percent greater risk of all-cause mortality (that is, risk of dying at any moment) than someone who does not smoke, representing a hazard ratio or (HR) of 1.40. This study found that someone of below-average VO max for their age and sex (that is, between the 25th and 50th percentiles) is at double the risk of all-cause mortality compared to someone in the top quartile 75th to 97.6th percentiles). Thus, poor cardiorespiratory fitness carries a greater relative risk of death than smoking.”*
一份2018年做的針對120,000人的JAMA研究發現，擁有最大攝氧量(VO2 Max）的人和較低的死亡率相關。抽菸的人比不抽菸的人高出40%的死亡率。JAMA研究發現，最大攝氧量排名在25%到50%百分位的人，比排名在75%以上攝氧量最大的那些人，死亡率是加倍的，甚至比抽菸的人還糟糕。
“These results were confirmed by a much larger and more recent study, published in 2022 in the Journal of the American College of Cardiology, looking at data from 750,000 US veterans ages thirty to ninety-five (see figure 9). This was a completely different population that encompassed both sexes and all races, yet the researchers found a nearly identical result: someone in the least fit 20 percent has 4.09 times greater risk of dying than a person in the top 2 percent of their age and sex category. Even someone of moderate fitness (40th to 60th percentile) is still at more than double the risk of all-cause mortality than the fittest group, this study found …”
(運動的重要性)和在2022年美國心臟病學院發布的一項研究的結論完全一致。這個研究爬梳了75萬名年齡介於30到95歲的美國退伍軍人，涵蓋了不同性別和各種族。心肺功能強健程度排在最後面20%的人，他的死亡率是排名前2%心肺功能最強者的4.09倍。而稍微有運動，心肺功能排名在後面40到60百分位的人，他們的死亡率是排名前2%心肺功能最強者的2倍以上。
“At a deeper biochemical level, exercise really does act like a drug. To be more precise, it prompts the body to produce its own, endogenous drug-like chemicals. When we are exercising, our muscles generate molecules known as cytokines that send signals to other parts of our bodies, helping to strengthen our immune system and stimulate the growth of new muscle and stronger bones. Endurance exercise such as running or cycling helps generate another potent molecule called brain-derived neurotrophic factor, or BDNF, that improves the health and function of the hippocampus, a part of the brain that plays an essential role in memory. Exercise helps keep the brain vasculature healthy, and it may also help preserve brain volume. This is why I view exercise as a particularly important part of the tool kit for patients at risk of developing Alzheimer’s disease-…”
就生物化學的深一層意義而言，運動的作用就有如藥物。更精確地說，運動促使身體自身產出內生性有若藥物般的化學物質。當我們運動的時候，我們的肌肉會產生細胞激素，對身體的其他部位送出訊息，協助我們加強免疫系統、刺激新肌肉的生長、強化骨骼。耐力訓練的運動，諸如跑步或騎自行車，會促使「腦源性神經營養因子」（Brain-Derived Neurotrophic Factor, BDNF）這種重要分子的產生，能增益大腦腦馬廻的健康及其功能，而人的記憶力主要受大腦這部份的影響。運動可以保持大腦循環系統的健康，而且可以協助維持腦容量。這也是為什麼我認為運動是病人很重要的工具，尤其是對易罹患阿茲海默症的高風險族群而言。
“The data demonstrating the effectiveness of exercise on lifespan are as close to irrefutable as one can find in all human biology. Yet if anything, I think exercise is even more effective at preserving healthspan than extending lifespan. There is less hard evidence here, but I believe that this is where exercise really works its magic when applied correctly. I tell my patients that even if exercise shortened your life by a year (which it clearly does not), it would still be worthwhile purely for the healthspan benefits, especially in middle age and beyond.”
研究的資料顯示運動能有效延長壽命，這是無庸置疑的，大家都可以從人體生物學中得到印證。我認為，運動不止是可以延長壽命，它更可以讓我們過更久有品質的生活。雖然在這方面具體的研究不多，但是我相信一旦正確地運動，奇妙的結果就會產生。我告訴我的病人，縱使運動會讓你減壽一年(其實不會)，運動可以讓你活得更健康，依然是值得去做的，尤其是已經是中年或者步入老年的人。
“One of the prime hallmarks of aging is that our physical capacity erodes.
Our cardiorespiratory fitness declines for various reasons that begin with lower cardiac output, primarily due to reduced maximum heart rate. We lose strength and muscle mass with each passing decade, our bones grow fragile and our joints stiffen, and our balance falters, a fact that many men and women discover the hard way, by falling off a ladder or while stepping off a curb.”
老化的主要特徵是生理功能的退化。我們的心肺功能降低，緣於各種不同的原因，起初是心臟的輸出減弱，主要是最高心率的降低。我們沒有力氣，我們的肌肉每十年益形消瘦，我們的骨骼變得更脆弱而關節更不靈活，我們平衡感變差，這些都是很多人不管男女都會痛苦地感受到的，譬如從梯子上摔下來，或者在跨過小坡崁時居然跌倒。
“To paraphrase Hemingway, this process happens in two ways: gradually, and then suddenly. The reality of the situation is that old age can be really tough on our bodies. Longitudinal and cross-sectional studies find that fat-free mass (meaning mostly muscle mass) and activity levels remain relatively consistent as people age from their twenties and thirties into middle age. But mass decline steeply after about age sixty-five, and the even more steeply after about seventy-five. It’s as if people just fall off a cliff sometime in their mid-seventies.”
借用海明威在小說中的話來說明，老化的過程有兩種方式，逐漸地老化，以及之後的跳崖式突然老化。真實的狀況是，老化對我們的身體十分嚴厲。時間序列或同時間的橫斷研究都發現，身體非脂類的固狀物的質量(主要是指肌肉的質量)及其活力，在年齡二、三十歲一直到中年，都還會維持在某一定的水準。但是，那些質量在過了65歲之後，就會迅速減少，在75歲之後減得又更快。那就好像人在75歲左右，直接墜崖一樣。
“Exercise in all its forms is our most powerful tool for fighting this misery and reducing our risk of death across the board. It slows the decline, not just physically but across all three vectors of healthspan, including cognitive and emotional health…”
運動是各種方式中最可以抵抗這種墜崖式衰退的方法，可以降低各種原因所𦘦致的死亡風險。老化所導致的衰退的可怕之處，不只是在體力上，也在認知能力和精神健康上面，這三個面向，都是攸關身心全方位健康的因素。
……..
如果您已經有運動的習慣，恭喜您。如果沒有，何不馬上去做呢？加油，大家一起加油，為老年存更多力量的本。
P.S. There’s a passage in Ernest Hemingway’s novel The Sun Also Rises in which a character named Mike is asked how he went bankrupt. “Two ways,” he answers. “Gradually, then suddenly.”
*: Peter Attia, MD with Bill Gifford, “Outlive, the science & art of longevity,” 2023, Harmony Books
2023/12/28 Outlive, the science & art of longevity Damakey
