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。
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。
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——当你看到社群媒体上关于咖啡有害的说法时，这一点值得牢记。
