喝咖啡护心又护肝 但别超过这个量Drinking coffee can protect the heart and liver, but don't exceed this amount

　　喝咖啡护心又护肝，那是不是喝得越多越好呢？

　　近日，美国心脏学会发表科学声明，系统回顾了咖啡因与心血管病的所有最新证据。声明显示，喝咖啡对血压、血糖和血脂都会产生影响。

　　喝咖啡对血压、血糖、血脂都有影响

　　血压。咖啡因会在短时间内升高血压。摄入250毫克咖啡因，高血压患者血压升幅比普通人高1.5倍以上，但效果会在几小时后消退。长期来看，每天喝1杯至3杯咖啡，高血压发生风险会轻微升高。

　　血糖。很多糖友喝完咖啡后血糖会轻微上浮，因为咖啡因会短暂抑制胰岛素敏感性。但长期研究发现，每天喝咖啡者，2型糖尿病风险显著降低。

　　血脂。咖啡中含一种油脂类成分——咖啡醇。若咖啡中保留咖啡醇（比如用法压壶制作咖啡），长期大量饮用会升高血脂。但如果用滤纸过滤掉咖啡醇，基本不会对血脂产生负面影响。

　　喝咖啡对心脏疾病有影响

　　心律失常。咖啡因会小幅增加心室早搏（室早）发作频率，但适量喝咖啡不会诱发室速、室颤这类致命心律失常，房颤患者适量喝咖啡也可降低39%的房颤复发风险。

　　冠心病和心衰。每天喝2杯至3杯咖啡，有利于降低冠心病和心力衰竭风险，但不建议过量饮用。

　　脑卒中。既往研究发现，喝咖啡和脑卒中风险呈U形曲线关系，每天喝3杯至4杯咖啡，脑梗死风险降低21%。

　　喝咖啡降低多种肝病风险

　　7月，国际权威期刊《临床胃肠病学和肝病学》发表了一项覆盖35万余名参与者的研究，结果发现，每天喝1杯至2杯咖啡的人，与完全不喝咖啡的人相比：肝硬化风险降低20%，肝癌风险降低24%，肝病相关死亡风险降低31%。

　　这并不是第一次发现咖啡有护肝效果。2021年，《BMC公共卫生》期刊刊发的一项纳入近50万人、随访长达10年的大规模研究就发现，与不喝咖啡的人相比，适量喝咖啡的人：慢性肝病风险降低21%，非酒精性脂肪肝风险降低20%，慢性肝病相关死亡风险更是大幅下降49%。

　　别超过这个“安全剂量”

　　既然咖啡护心又护肝，那是不是喝得越多越好呢？当然不是！日常生活中，不顾上限地敞开了喝，反而会带来风险。

　　医生建议，普通成人每天摄入咖啡因不超400毫克，约3杯至5杯黑咖啡（每杯240毫升）；避免喝摩卡、焦糖玛奇朵等花式咖啡。房颤、冠心病或心衰患者可视情况喝2杯至3杯黑咖啡，也可加点牛奶。

　　咖啡尽量不要空腹喝。空腹喝咖啡，不仅会降低食欲，而且对肠胃也有刺激，建议吃完早餐或午餐后饮用，此时喝咖啡可以帮助消化。胃不好的人群，尤其是患有慢性胃炎、胃食管反流等基础疾病的人群，更是建议别空腹喝咖啡。

Drinking coffee protects both the heart and the liver, isn't drinking more the better?

Recently, the American Heart Association released a scientific statement that systematically reviews all the latest evidence on the relationship between caffeine and cardiovascular disease. The statement shows that drinking coffee can have an impact on blood pressure, blood sugar, and blood lipids.

Drinking coffee has an impact on blood pressure, blood sugar, and blood lipids

Blood pressure. Caffeine can increase blood pressure in a short period of time. Consuming 250 milligrams of caffeine can increase blood pressure by more than 1.5 times in hypertensive patients compared to the general population, but the effect will fade after a few hours. In the long run, drinking 1 to 3 cups of coffee per day will slightly increase the risk of hypertension.

Blood sugar. Many diabetics experience a slight increase in blood sugar levels after drinking coffee, as caffeine temporarily inhibits insulin sensitivity. However, long-term studies have found that people who drink coffee every day have significantly reduced the risk of type 2 diabetes.

Blood lipids. Coffee contains a lipid component called caffeic alcohol. If caffeic alcohol is retained in coffee (such as when making coffee with a press pot), long-term heavy consumption can increase blood lipids. But if coffee alcohol is filtered out with filter paper, it will not have a negative impact on blood lipids.

Drinking coffee has an impact on heart disease

Arrhythmia. Caffeine can slightly increase the frequency of premature ventricular contractions, but moderate coffee consumption does not induce fatal arrhythmias such as ventricular tachycardia and fibrillation. Moderate coffee consumption in atrial fibrillation patients can also reduce the risk of atrial fibrillation recurrence by 39%.

Coronary heart disease and heart failure. Drinking 2 to 3 cups of coffee per day can help reduce the risk of coronary heart disease and heart failure, but excessive consumption is not recommended.

Stroke. Previous studies have found a U-shaped relationship between coffee consumption and stroke risk, with drinking 3 to 4 cups of coffee per day reducing the risk of stroke by 21%.

Drinking coffee reduces the risk of various liver diseases

In July, the international authoritative journal Clinical Gastroenterology and Hepatology published a study covering more than 350000 participants, which found that people who drink 1 to 2 cups of coffee per day have a 20% lower risk of cirrhosis, a 24% lower risk of liver cancer, and a 31% lower risk of liver disease-related death compared to those who do not drink coffee at all.

This is not the first time that coffee has been found to have a liver protective effect. In 2021, a large-scale study involving nearly 500000 people and followed up for 10 years published in the BMC Public Health journal found that compared to non coffee drinkers, moderate coffee drinkers had a 21% lower risk of chronic liver disease, a 20% lower risk of non-alcoholic fatty liver disease, and a significant 49% lower risk of chronic liver disease-related mortality.

Don't exceed this' safe dose '

Since coffee protects both the heart and the liver, shouldn't the more you drink, the better? Of course not! In daily life, drinking without limits can actually bring risks.

Doctors suggest that the average adult should consume no more than 400 milligrams of caffeine per day, about 3 to 5 cups of black coffee (240 milliliters per cup); Avoid drinking fancy coffee such as mocha and caramel macchiato. Patients with atrial fibrillation, coronary heart disease, or heart failure can drink 2 to 3 cups of black coffee and add some milk depending on the situation.

Try not to drink coffee on an empty stomach. Drinking coffee on an empty stomach not only reduces appetite, but also stimulates the digestive system. It is recommended to drink coffee after breakfast or lunch as it can aid digestion. People with poor stomach, especially those with underlying diseases such as chronic gastritis and gastroesophageal reflux, are advised not to drink coffee on an empty stomach.