Countless arguments have been waged over the superiority of one beverage over the other. But what does the scientific evidence say?
關于這兩種飲料孰優孰劣的問題已經引發了無數爭論。但是科學證據是怎樣的呢？

George Orwell may have written that “tea is one of the mainstays of civilization in this country” – but even we British have to acknowledge that our national drink is facing stiff competition from the espressos, cappuccinos, and lattes invading our shores.
喬治·奧威爾或許寫過“茶是這個國家文明的一個支柱”這樣的句子——但我們英國人也要承認，隨著濃咖啡、卡布奇諾和拿鐵侵入國門，我們的全民飲料正面臨著激烈的競爭。

Despite the dangers of wading into such a charged argument, BBC Future decided to weigh up the relative merits of each drink. There’s no accounting for taste, of course, but we have combed the scientific literature for their real, measurable effects on our body and mind.
盡管探討這個敏感話題充滿風險，“BBC未來”欄目還是決定對每種飲品的相對優點進行評估。當然，百人百味，但通過精心梳理科學文獻，我們找出了它們對人體和大腦真實的、可測量的影響。

The wake-up call
醒腦劑

For many, the caffeine kick is the primary reason we choose either beverage; it’s the oil to our engines when we’re still feeling a bit creaky in the morning. Based purely on its composition, coffee should win hands down: a cup of tea has about half the dose (40 milligrams) of the stimulant caffeine that you would find in a standard cup of brewed filter coffee (80 to 115 milligrams). Yet this doesn’t necessarily reflect the jolt of the wake-up call.
對許多人來說，咖啡因的興奮作用是我們選擇這兩種飲料的主要原因；在睡眼惺忪的清晨，咖啡因就像石油一樣，給我們身體的引擎以能量。只考慮成分的話，咖啡可以輕松獲勝：一杯茶的咖啡因含量（40毫克）大約只有標準杯過濾咖啡（80至115毫克）的一半。然而，這并非反映了它們的醒腦作用。

Dosing subjects with either tea or coffee, one study found that both beverages left subjects feeling similarly alert later in the morning.
通過讓被試者飲用一定量的茶或咖啡，一項研究發現，這兩種飲料都能讓受試者在早晨晚些時候感到同樣清醒。

Verdict: Against logic, tea seems to provide just as powerful a wake-up call as coffee. It’s a draw.
結論：雖然邏輯上講不通，但茶跟咖啡的醒腦作用似乎不相上下。平局。

Sleep quality
睡眠質量

The biggest differences between coffee and tea may emerge once your head hits the pillow.
咖啡和茶之間最大的差異或許將集中體現在睡眠上。

Comparing people drinking the same volume of tea or coffee over a single day, researchers at the University of Surrey in the UK confirmed that although both drinks lend similar benefits to your attention during the day, coffee drinkers tend to find it harder to drop off at night – perhaps because the higher caffeine content finally catches up with you.
通過對比研究每天飲用等量的茶或咖啡的人，英國薩里大學的研究人員證實，盡管兩種飲料在白天對注意力集中的作用差不多，但或許是因為咖啡里的咖啡因含量更高，喝咖啡的人晚上更難入睡。

Tea drinkers, in contrast, had longer and more restful slumbers.
相比之下，喝茶的人睡得更久更香。

Verdict: Tea offers many of the benefits of coffee, without the sleepless nights – a clear win.
結論：茶不僅擁有咖啡的許多好處，還不會帶來不眠之夜——完勝

Tooth staining
牙齒變黃

Along with red wine, coffee and tea are both known to turn our pearly whites a murky yellow and brown. But which is worse?
眾所周知，紅酒、咖啡和茶都會把潔白的牙齒慢慢染成暗黃色或棕褐色。但哪個最糟糕？

Most dentists seem to agree that tea’s natural pigments are more likely to adhere to dental enamel than coffee’s – particularly if you use a mouthwash containing the common antiseptic chlorhexidine, which seems to attract and bind to the microscopic particles.
大多數牙醫似乎一致認為，茶中的天然色素比咖啡的更易附著于牙釉質之上——尤其當你使用常見的洗必泰漱口水時，其中的消毒洗必泰能吸引并聚合微觀粒子。

Verdict: If you want a perfect smile, coffee may be the lesser of two evils.
結論：如果你想展現完美笑容，兩害相權取其輕，咖啡也許還好一點。

A balm for troubled souls…
不安靈魂的慰藉……

In England, it’s common to give “tea and sympathy” to a distressed friend – the idea being that a cup of Earl Grey is medicine for troubled minds. In fact, there is some evidence that tea can soothe your nerves: regular tea drinkers do tend to show a calmer physiological response to unsettling situations (such as public speaking), compared to people drinking herbal infusions. Overall, people who drink three cups a day appear to have a 37% lower risk of depression than those who do not drink tea.
英國人喜歡給煩惱苦悶的朋友送去“茶與同情”——這是由于他們認為伯爵茶能夠治愈不安的靈魂。事實上，有證據表明，茶可以舒緩神經：與喝中草藥的人相比，經常飲茶者在處理一些令人不安的情況（如公開演講）時確實表現得更為鎮靜。總的來說，每天喝三杯茶的人比不喝茶的人罹患抑郁癥的風險要低37%。

Coffee doesn’t have the same reputation; indeed, some report that it makes them feel like their nerves are jangling. Yet there is some evidence that it too may protect against long-term mental health problems. A recent “meta-analysis” (summarising the results of studies involving more than 300,000 participants) found that each cup of coffee a day seems to reduce your risk of developing depression by around 8%. In contrast, other beverages (such as sweetened soft drinks) only increase your risk of developing mental health problems.
咖啡并沒有這種功效；事實上，有些人覺得咖啡會讓人有些神經錯亂。但是也有證據表明，咖啡能預防長期精神問題。最近的一項“薈萃分析”（總結了超過30萬名參與者的研究結果）發現，每天一杯咖啡的人患抑郁癥的風險比常人要低大約8%。相比之下，其他飲料（如甜味軟飲）只會增加患精神疾病的風險。

Verdict: Based on this limited evidence, it’s a draw.
結論：基于有限的證據，平局。

…and a balm for bodies……
身體的萬金油

Similarly tantalising, though preliminary, epidemiological studies have suggested that both coffee and tea offer many other health-giving benefits. A few cups of either beverage a day appears to reduce your risk of diabetes, for instance.
流行病學研究雖然才剛剛起步，但也很吸睛。該領域研究表明，咖啡和茶都對身體還有其它益處。例如，每天喝幾杯會降低患糖尿病的風險。

Both drinks also seem to moderately protect the heart, although the evidence seems to be slightly stronger for coffee, while tea also appears to be slightly protective against developing a range of cancers – perhaps because of its antioxidants.
飲用這兩種飲料能對心臟起到一定的保護作用，盡管證據顯示似乎咖啡的功效更強，但許是因為茶中的抗氧化劑，茶對預防癌癥也有些許功效。

Verdict: Another draw – both drinks are a surprising, health-giving elixir.
結論：還是平局——這兩種飲料都是神奇的、有益健康的靈丹妙藥。

Overall verdict: Much as we Brits would have liked tea to come out the clear victor, we have to admit there is little between the two drinks besides personal taste. Based solely on the fact that it allows you to get a better night’s sleep, we declare tea the winner.
總結：大部分英國人都會覺得茶很明顯更勝一籌。但除了個人口味，必須承認的是兩者的差異并不大。僅僅基于能讓人好眠這一點，茶無疑是贏家。

Vocabulary

pigment: 色素
dental enamel: 牙釉質
antioxidant: 抗氧化劑
elixir: 萬能藥

英文來源：BBC
譯者：程玉晴
審校&編輯：丹妮