Q: I’ve heard that drinking coffee without food in the morning can damage the stomach lining. Is that true?
问：我听说早上只喝咖啡不吃东西会损害胃粘膜。这是真的吗?
For many people, enjoying a freshly brewed cup of coffee first thing in the morning is a nonnegotiable way to start the day. But the idea that taking a sip without food could harm your gut — or contribute to other ills like bloating, acne, hair loss, anxiety, thyroid issues or painful periods, as some on social media have claimed — has garnered as much popularity as incredulity.
对许多人来说，早上第一件事就是喝一杯鲜煮咖啡，必须这样开启新的一天。但有人说空腹喝咖啡会伤害肠道——或者像一些社交媒体上说的，会导致腹胀、痤疮、脱发、焦虑、甲状腺问题或痛经等其他疾病——这些说法广为流传，但也有不少质疑。
Researchers have been investigating the benefits and harms of drinking coffee, especially as they relate to the gut, since the 1970s, said Kim Barrett, a professor of physiology and membrane biology at the University of California, Davis School of Medicine, and a member of the governing board of the American Gastroenterological Association. Fortunately, the stomach can withstand all kinds of irritants, including coffee.
加州大学戴维斯医学院生理学和膜生物学教授、美国胃肠病协会理事会成员金·巴雷特说，自20世纪70年代以来，研究人员一直在调查喝咖啡的好处和坏处，尤其是与肠道相关的方面。幸运的是，胃可以抵御各种刺激物，包括咖啡。
“The stomach has so many ways to protect itself,” Dr. Barrett said. For example, it secretes a thick mucus layer that creates a powerful shield between the stomach lining and whatever you ingest. That shield also protects the stomach from its own natural acidic environment needed to break down food, she explained.
“胃有很多方法来保护自己，”巴雷特说。例如，它会分泌一层厚厚的黏液，在胃粘膜和你摄入的任何东西之间形成强大的防护罩。她解释说，这种屏障还可以保护胃免受分解食物所需的自然酸性环境影响。
You’d have to consume a very harsh substance “for the defenses of the stomach to be breached because it’s constantly in a very adverse and damaging environment,” she said. “That’s just how the stomach does its job.”
你得摄入一种非常刺激的物质“才能突破胃的防御系统，因为它一直处于非常不利和有害的环境中，”她说。“这就是胃的运作方式。”
How does coffee affect the gut?
咖啡是如何影响肠道的？
Irritants like alcohol, cigarette smoke and nonsteroidal anti-inflammatory drugs — such as ibuprofen (Advil, Motrin) or naproxen (Aleve) — are well known to alter our stomach’s natural defense mechanisms and injure its lining, said Dr. Byron Cryer, chief of internal medicine at Baylor University Medical Center in Dallas.
达拉斯贝勒大学医学中心内科主任拜伦·克莱尔博士说，众所周知，酒精、香烟的烟雾和非甾体类抗炎药——如布洛芬或萘普生——会改变胃的自然防御机制，损伤其内膜。
His research lab specializes in understanding how different medications and other chemicals can harm the stomach and small intestine. While certain irritants can make the stomach more vulnerable to acid and ulcer formation, multiple large studies have found that this is not the case with coffee. A 2013 study of more than 8,000 people living in Japan, for example, found no significant association between coffee consumption and ulcer formation in the stomach or intestine — even among those who drank three or more cups per day.
他的研究实验室专门研究各种药物和其他化学物质对胃和小肠的伤害。虽然某些刺激物会使胃更容易产生酸和溃疡，但多项大型研究发现，咖啡并不会。例如，2013年一项针对8000多名日本居民的研究发现，喝咖啡与胃溃疡或肠溃疡形成之间没有显著的联系——即使是那些每天喝三杯或三杯以上咖啡的人。
“Coffee, even in a concentrated form, is not likely to cause objective injury to the stomach,” Dr. Cryer said. “And much less at the typical doses in usual beverages.”
“咖啡，即使是浓缩咖啡，也不太可能对胃造成客观上的伤害，”克莱尔说。“而且在普通饮料中，咖啡的典型剂量要少得多。”
Nonetheless, coffee does have an effect on the gut — it can speed up the colon and induce a bowel movement, and coffee increases acid production in the stomach.
尽管如此，咖啡确实对肠道有影响——它可以加速结肠蠕动，诱导排便，咖啡还会增加胃酸分泌。
Outside of the gut, the caffeine from coffee is well known to increase heart rate and blood pressure. And if you drink it too close to bedtime, it can disrupt your sleep. But these changes are temporary, Dr. Cryer said.
除了对肠道的影响，众所周知，咖啡中的咖啡因能提高心率和血压。如果临睡前喝咖啡会扰乱睡眠。但克莱尔说，这些变化都是暂时的。
Will increased stomach acid cause any issues?
胃酸增加会引起什么问题吗？
Drinking coffee on an empty stomach is unlikely to cause any damage to your stomach, but it could theoretically provoke heartburn, Dr. Barrett said.
巴雷特表示，空腹喝咖啡不太可能造成胃损伤，但理论上可能引起胃灼热。
We know that coffee sets off stomach acid production, but if you have food in your stomach, or if you drink your coffee with milk or creamer, that will aid in creating a buffer that helps to neutralize that acid. So drinking coffee, especially if it’s black, without a meal can reduce the stomach’s pH more than it would if you drank it with milk or with a meal, Dr. Barrett said.
众所周知，咖啡会促进胃酸的产生，但如果胃中有食物，或在咖啡中加入牛奶或奶精，可以起到缓冲作用，帮助中和胃酸。因此，巴雷特表示，比起咖啡加牛奶或吃饭时喝咖啡，空腹喝咖啡——尤其是黑咖啡——更能降低胃中pH值。
Although a slightly lower pH is no problem for your stomach lining, it could pose an issue for the lining of your esophagus because it is far more vulnerable to damage from acid. Furthermore, a few studies have shown that coffee can relax and open the sphincter that connects the esophagus to the stomach, which hypothetically could allow acid from the stomach to more easily splash upward into the esophagus and cause unpleasant heartburn symptoms.
虽然pH值稍低不会影响胃粘膜，但可能会对食道内壁造成问题，因其更容易受到胃酸损害。此外，一些研究表明，咖啡可以放松并打开连接食道与胃部的括约肌，理论上可能会让胃酸更容易上涌至食道，从而引起令人不适的胃灼热症状。
But even there, the data is mixed. A 2014 review of 15 studies across Europe, Asia and the United States found no link between coffee consumption and heartburn symptoms, while, in contrast, a 2020 study using data from more than 48,000 female nurses found a higher risk of heartburn symptoms among coffee drinkers.
但即便在这个问题上，数据表明的情况依然复杂。针对2014年来自欧洲、亚洲和美国的15项研究的综述发现，喝咖啡与胃灼热症状没有联系；但2020年一项使用了4.8万多名女护士数据的研究发现，喝咖啡的人出现胃灼热症状的风险更高。
To understand how coffee might affect the esophagus, scientists also study a condition called Barrett’s esophagus, which occurs when the esophagus is damaged from chronic exposure to stomach acid, such as in people with longstanding acid reflux issues. With this condition, the cells lining the esophagus morph into hardier, stomach-like cells to protect themselves from the acid. These changes can increase the risk of esophageal cancer, especially if you have a family history of the condition or if you smoke. But reassuringly, a 2016 study of veterans in the United States found no similar relationship with coffee consumption. The authors concluded that for Barrett’s esophagus, avoiding coffee would probably not be helpful.
为了了解咖啡对食道的潜在影响，科学家还研究了所谓的巴雷特食道症，这种病症指的是食道因长期接触胃酸而受损，比如一直有胃酸反流问题的人。在这种情况下，食道内壁的细胞会变成更顽强的胃样细胞，以保护自身免受胃酸侵害。这些变化会增加食道癌风险，特别是对有食道癌家族史或吸烟的人。但令人欣慰的是，2016年一项针对美国退伍军人的研究发现，该病症与喝咖啡没有类似关系。该研究作者得出结论称，戒掉咖啡恐怕并不能改善巴雷特食道症问题。
So what should I do?
那我该怎么做？
Practically speaking, as a gastroenterologist, I usually tell my patients to take note of their symptoms. If they consistently notice a burning pain in their chest or a sour taste in their mouth after drinking coffee, they may want to cut down — or consider an antacid. Adding a splash of milk or cream or a small bite of food with your morning cup can also help. But if you aren’t noticing any symptoms, you’re probably someone who doesn’t experience significant reflux after coffee and can keep drinking it in peace.
实际上，作为一名胃肠病学家，我通常会建议患者留心自身的症状。如果在喝咖啡后感到胸部灼痛或嘴里有酸味，可能就需要减少摄入量，或考虑服用解酸药物。在晨间咖啡中加入一点牛奶或奶油，或辅以小食，都能起到帮助。但若是没发现任何症状，那可能就是喝咖啡后胃酸不会明显反流，大可以安心饮用。
Dr. Cryer regularly enjoys his coffee as a latte or cappuccino — the steamed milk cuts down the bitterness, he said. And, in general, he added, coffee drinking has many health benefits, including links to longevity, a lower risk of cardiovascular disease and protection against many cancers, including liver, prostate, breast and colorectal cancer.
克莱尔常喝拿铁或卡布奇诺，他说加入奶泡可以减少苦涩口感。他还表示，喝咖啡总体来说对健康有很多好处，包括延年益寿、降低心血管疾病风险，还能预防多种癌症，包括肝癌、前列腺癌、乳腺癌和结直肠癌。
“There’s far more evidence for coffee’s benefits than harms,” Dr. Cryer said — which is something worth keeping in mind, he added, while you scroll through social media stories that profess the brew’s detriments.
“咖啡利大于弊的证据要多得多，”克莱尔说——当你看到社交媒体上关于咖啡有害的说法时，这一点值得牢记。
Trisha医生是麻省综合医院一名胃肠病学家，也为《纽约时报》供稿。
翻译：晋其角、Harry Wong
