咖啡，是职场人、备考族的“续命神器”，一杯香醇的咖啡既能提神醒脑，也藏着不少健康学问。咖啡对身体有哪些影响？是否会让人成瘾？怎么喝才更健康？这篇科普为您一一解答。

市面上的咖啡大致可分为黑咖啡和花式咖啡，黑咖啡仅由咖啡和水制成（如美式），花式咖啡则添加了牛奶、砂糖、巧克力、奶油等配料（如拿铁、摩卡、玛奇朵）。今天我们主要围绕黑咖啡（包括速溶咖啡、现磨咖啡）展开。

咖啡的健康两面性

目前，主流研究认为，咖啡无充分证据表明会增加癌症风险，反而能降低肝癌、子宫内膜癌、皮肤基底细胞癌、口腔癌及乳腺癌风险，还可降低糖尿病、心血管疾病的发病概率。部分研究显示，咖啡可有效改善胃肠蠕动，有可能降低非酒精性脂肪肝、肝硬化、抑郁症、阿尔茨海默病、帕金森病等疾病风险，或降低全因死亡风险，相关结论待进一步验证。

饮用禁忌需注意：过量饮用易增加骨质疏松风险；咖啡对睡眠的影响存在个体差异，临近就寝时间甚至午后应避免摄入；应避免与酒精混合饮用，咖啡因会掩盖酒精的抑制作用，使饮酒者感知醉酒程度降低，易导致饮酒过量。

咖啡成瘾？真相来了

咖啡中的生物活性物质包括咖啡因、绿原酸、葫芦巴碱、咖啡醇等，其中咖啡因和绿原酸含量相对较高。咖啡因又名咖啡碱，广泛存在于咖啡、茶叶、马黛茶、可可、瓜拉纳、可乐果等60余种植物中。咖啡因具有温和的中枢神经系统兴奋作用，少数人停饮后会出现头痛、乏力、情绪波动等反应，所以有人认为这是“咖啡成瘾”。

然而，目前的科学证据并不支持“咖啡因成瘾”。世界卫生组织、美国食品药品监督管理局、加拿大卫生部、澳新食品标准局、国际食品信息委员会等机构均不认为咖啡具有成瘾性。停饮咖啡后出现的上述反应温和且短暂，通过逐步减少咖啡因摄入量，即可有效避免。

科学喝法美美享用

控制摄入量：健康成年人每日咖啡因摄入量不要超过400mg，约等于4-5杯滴漏咖啡（250ml/杯）、8-9杯红茶（250ml/杯）、5瓶能量饮料（250ml/瓶）或8-9瓶可乐（355ml/瓶）中的咖啡因含量。不同饮品咖啡因含量排序：低因咖啡＜茶水（白茶＜绿茶＜红茶）＜速溶咖啡＜滴漏咖啡。

选对饮用时间：优选晨间或上午，此时饮用对睡眠、昼夜节律影响更小。此外，咖啡中的抗炎活性物质还能针对性缓解清晨机体的炎症高峰，更易发挥心血管保护作用。

来源：临床营养科

作者：赵文芝

荐稿：贾平平

来源：北京号

作者: 北京世纪坛医院官方号

Coffee is a "life-saving tool" for professionals and test takers. A cup of fragrant coffee can not only refresh the mind, but also contain a lot of health knowledge. What are the effects of coffee on the body? Will it make people addicted? How to drink healthier? This popular science article will provide you with answers one by one.

Coffee on the market can be roughly divided into black coffee and fancy coffee. Black coffee is only made from coffee and water (such as American style), while fancy coffee adds ingredients such as milk, sugar, chocolate, cream (such as latte, mocha, macchiato). Today we will mainly focus on black coffee (including instant coffee and freshly ground coffee).

The health duality of coffee

At present, mainstream research believes that coffee does not have sufficient evidence to increase the risk of cancer, but can reduce the risk of liver cancer, endometrial cancer, skin basal cell cancer, oral cancer and breast cancer, as well as the incidence of diabetes and cardiovascular disease. Some studies have shown that coffee can effectively improve gastrointestinal peristalsis, potentially reducing the risk of non-alcoholic fatty liver disease, cirrhosis, depression, Alzheimer's disease, Parkinson's disease, and other diseases, or reducing the risk of all-cause mortality. The relevant conclusions need further verification.

Drinking taboos should be noted: excessive consumption can increase the risk of osteoporosis; The impact of coffee on sleep varies among individuals, and it should be avoided near bedtime or even in the afternoon; It should be avoided to mix with alcohol for consumption, as caffeine can mask the inhibitory effect of alcohol, reducing the perception of drunkenness and leading to excessive drinking.

Coffee addiction? The truth has arrived

The bioactive substances in coffee include caffeine, chlorogenic acid, cucurbitacin, caffeic acid, etc., among which caffeine and chlorogenic acid have relatively high contents. Caffeine, also known as caffeine, is widely present in more than 60 plant species such as coffee, tea, maday tea, cocoa, guarana, and kola nut. Caffeine has a mild central nervous system excitatory effect, and a few people may experience headaches, fatigue, emotional fluctuations, and other reactions after stopping drinking, so some people believe that this is "coffee addiction".

However, current scientific evidence does not support 'caffeine addiction'. The World Health Organization, the US Food and Drug Administration, Health Canada, the Australian and New Zealand Food Standards Agency, the International Food Information Commission, and other organizations do not consider coffee to be addictive. The above reactions that occur after stopping coffee consumption are mild and short-lived, and can be effectively avoided by gradually reducing caffeine intake.

Scientific drinking methods and delicious enjoyment

Control intake: Healthy adults should not exceed a daily caffeine intake of 400mg, which is approximately equivalent to the caffeine content in 4-5 cups of drip coffee (250ml/cup), 8-9 cups of black tea (250ml/cup), 5 bottles of energy drinks (250ml/bottle), or 8-9 bottles of cola (355ml/bottle). Ranking of caffeine content in different beverages: Low caffeine coffee<tea water (white tea<green tea<black tea)<instant coffee<drip coffee.

Choose the right drinking time: preferably in the morning or early morning, when drinking has less impact on sleep and circadian rhythm. In addition, the anti-inflammatory active substances in coffee can also effectively alleviate the morning inflammation peak in the body, making it easier to exert cardiovascular protection.

Source: Clinical Nutrition Department

Author: Zhao Wenzhi

Recommended article: Jia Pingping

Source: Beijing Number

Author: Official account of Beijing Shijitan Hospital