真的建议：这 8 类人要少喝咖啡！Real advice: These 8 types of people should drink less coffee!

对于现代人来说，咖啡已经逐渐成了流行饮品，更是很多上班族每日必备的“续命神器”。

目前有很多研究提到常喝咖啡对健康有益，比如能提神醒脑、缓解疲劳、预防 2 型糖尿病、预防某些癌症等。苏州大学研究团队的一项研究显示：饮用咖啡竟可抵消久坐带来的危害——每天久坐时长≥6 小时且不喝咖啡者的死亡风险是每天坐＜6 小时且喝咖啡者的 1.58 倍；不喝咖啡的人群里，久坐时间越长，全因死亡风险越高。

即便如此，咖啡也并非适合所有人，有 8 类人不能盲目喝咖啡，一定要特别注意。

1.睡眠不好的人

咖啡中含有较高的咖啡因，具有一定的提神效果。咖啡因与机体供能物质三磷酸腺苷（ATP）的代谢物腺苷结构相似，可竞争结合引起疲劳和睡眠信号的受体，发挥促进觉醒、改善疲劳的生物活性。

正因为如此，很多上班族都要依靠咖啡来打起精神，努力工作。

有研究显示：咖啡因在人体吸收迅速，一般在饮用后 15 分钟至 2 小时就能达到峰值，扩散全身，并跨越血脑屏障。在成人体内的半衰期一般为 2.5~4.5 小时。所以，一般情况下在计划睡觉的 5 小时以前喝咖啡，对正常人的睡眠不会有太大影响，比如 22 点睡觉，那就下午 5 点之前喝咖啡。

不过，不同人群对咖啡因的耐受程度有差异，对于本身就睡眠不好、存在失眠、睡眠障碍的人群还是得尽量少喝或不喝咖啡。

2.心律失常人群

虽然喝咖啡后心跳加速是正常现象，但仍然需要重视，特别是对于本身就有心律失常的人群。

心律失常主要是由心脏电传导异常引起的心跳不规则、过快或过慢。超过 80%的美国医生建议存在心悸或心律失常的病人戒断或减少咖啡因的摄入量。

另外还有一些研究表明：对于大多数人，即使是心律失常病人或心律失常高风险人群，尽管没有明确定义咖啡因危害的阈值，但每天 400 毫克以下的咖啡因摄入量似乎是安全的，甚至可能对心律失常具有保护作用；但是对于恶性心律失常人群以及咖啡因敏感的心律失常高风险人群来说，还是要尽量避免摄入咖啡因。

400 毫克的咖啡因相当于不超过 4 杯纯咖啡（150 毫升/杯），如果是买来的咖啡，可以对比包装标签上每杯咖啡因的含量来计算杯数；如果是一小包 1.8~2 克的速溶咖啡，一般每天最多不超过 5 袋。

3.有胃病的人群

咖啡会刺激胃肠道，使胃酸的分泌增加。

这对于胃功能正常的人来说，不会影响健康。但对于本身就有胃病，比如患有胃溃疡、胃酸分泌过多、胃食管反流病的人群，经常或者过量饮用咖啡可能会导致恶心、呕吐、胃反酸、烧心等症状。

4.肠易激综合征患者

肠易激综合征是很常见的功能性肠病，患者可能会频繁地腹泻、便秘。

咖啡因在消化系统中可刺激胃酸、胆囊收缩素分泌，从而促进结肠运动，引起腹泻等症状。一般情况下，肠易激综合征患者对咖啡因比较敏感，饮用后可能会增加胃肠不适、腹泻的症状。减少咖啡因的摄入，能降低肠易激综合征相关症状的发生。

5.骨质疏松人群

咖啡中的咖啡因、鞣酸等成分的确会影响钙吸收，同时咖啡因利尿会增加钙流失，但这对于健康人来说影响并不大。有研究提到：咖啡因对钙吸收的负面影响很小，只需 1~2 汤匙牛奶即可完全抵消。

欧洲食品安全局、美国食品药品监督管理局、加拿大卫生部、澳新食品标准局等食品安全监管机构基于大量人群数据，认为健康成年人咖啡因的每日摄入量在 400 毫克以内不会对心血管功能、行为、生殖和发育、骨骼健康造成不利影响，也没有急性中毒风险。所以，健康人群不用担心喝咖啡会导致骨质疏松。

不过，对于已经患有骨质疏松的人群，《老年骨质疏松性疼痛诊疗与管理中国专家共识（2024 版）》中建议应当避免过量饮用咖啡。

6.青光眼患者

有研究表明，咖啡中所含的咖啡因能导致青光眼患者眼压异常增高，为青光眼发展危险因素。眼压升高会引起视神经损伤和视功能损害，严重会导致失明。

所以，青光眼患者在日常生活中应避免饮用咖啡这类高含量咖啡因的饮品，避免眼压升高及波动对眼睛进一步造成伤害。

7.儿童、青少年

国际上目前暂时推荐的儿童及青少年咖啡因安全摄入量为每公斤体重不超过 2.5～3 毫克。也就是说，比如对于体重为 40 公斤的儿童及青少年来说，咖啡因的摄入量为 100~120 毫克，大概也就 1 杯咖啡。当然，最好还是不喝。

这是因为正处于生长发育期的孩子代谢咖啡因的能力比成年人弱，不仅会影响睡眠，也会影响身体发育。

《中国儿童青少年零食指南（2018）》中也提到：含有咖啡因成分的食物对儿童大脑发育和功能都会产生负面影响。因此 12 岁及以下儿童禁止摄取咖啡因，不喝浓茶、咖啡等含咖啡因的饮料。

8.孕妇和哺乳期女性

《咖啡与健康的相关科学共识》中提到，不建议孕妇喝咖啡，如果饮用，每天不超过2杯。尽管加拿大卫生部、美国妇产科学会、美国孕产协会等机构认为，孕期可少量饮用咖啡（每天不超过 150~300mg 咖啡因，约 2 杯），但不应鼓励孕妇喝咖啡。

因此，对于平时就没有喝咖啡习惯的女性，建议孕期和哺乳期不要饮用咖啡；而对于平时就一直有喝咖啡习惯的女性，最好限量饮用咖啡。

总结

虽然喝咖啡对健康颇为有益，但也得限量。《咖啡与健康的相关科学共识》中建议：普通成人每天咖啡因摄入量应控制在 400 毫克以内。

不同人群对咖啡因的耐受程度不同，建议文中提到的 8 类人群以及对咖啡因敏感的人群应当根据自身情况限制或者避免咖啡因的摄入。

参考文献

[1]Zhou H, Nie J, Cao Y, et al. Association of daily sitting time and coffee consumption with the risk of all-cause and cardiovascular disease mortality among US adults. BMC Public Health. 2024;24(1):1069. Published 2024 Apr 17. doi:10.1186/s12889-024-18515-9

[2]张曼宇,范红玲,翟文超.咖啡因与心律失常的相关性研究进展[J].中西医结合心脑血管病杂志,2024,22(8):1433-1437

[3]覃弦,宋军,侯晓华.肠易激综合征生活方式和饮食管理的研究进展[J].胃肠病学,2018,23(7):436-439

[4]Heaney, R P. “Effects of caffeine on bone and the calcium economy.” Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association vol. 40,9 (2002): 1263-70. doi:10.1016/s0278-6915(02)00094-7

[5]中国食品科学技术学会.咖啡因的科学共识[J/OL].中国食品学报:1-6[2024-05-17].http://kns.cnki.net/kcms/detail/11.4528.TS.20240416.1351.007.html.

[6]熊海波,易虹,刘鑫,代喻兵.咖啡因对青光眼患者眼压影响的Meta分析[J].检验医学与临床,2015,12(16):2362-2363

[7]曹卉娟,刘建平.孕期咖啡因摄入与流产相关性分析性研究系统综述[J].中国实用妇科与产科杂志,2014,30(12):945-950

[8]Lisowska A, Kasiak P, Rząca M. Assessment of caffeine intake in groups of pregnant and breastfeeding women: A cross-sectional analysis. Clin Nutr ESPEN. 2023 Oct;57:151-157. doi: 10.1016/j.clnesp.2023.06.041. Epub 2023 Jun 29. PMID: 37739650.

策划制作

审核丨阮光锋 科信食品与健康信息交流中心副主任 中华预防医学会健康传播分会委员

策划丨符思佳

责编丨王梦如

澎湃丨科普中国

For modern people, coffee has gradually become a popular beverage and a daily essential "life-saving tool" for many office workers.

At present, many studies mention that regular coffee drinking is beneficial to health, such as refreshing, relieving fatigue, preventing type 2 diabetes, and preventing some cancers. A study by a research team from Soochow University shows that drinking coffee can actually offset the harm caused by prolonged sitting - those who sit for ≥ 6 hours a day and do not drink coffee have a 1.58 times higher risk of death than those who sit for<6 hours a day and drink coffee; Among people who do not drink coffee, the longer they sit, the higher their risk of all-cause mortality.

However, coffee is not suitable for everyone. There are 8 types of people who should not blindly drink coffee and must pay special attention.

1. People who have poor sleep

Coffee contains a high amount of caffeine, which has a certain refreshing effect. Caffeine has a similar structure to adenosine, a metabolite of the body's energy supply substance adenosine triphosphate (ATP), and can compete to bind to receptors that cause fatigue and sleep signals, exerting biological activity to promote wakefulness and improve fatigue.

Because of this, many office workers rely on coffee to stay alert and work hard.

Studies have shown that caffeine is rapidly absorbed by the human body, typically reaching its peak within 15 minutes to 2 hours after consumption, spreading throughout the body, and crossing the blood-brain barrier. The half-life in the adult body is generally 2.5-4.5 hours. So, in general, drinking coffee 5 hours before planning to sleep will not have a significant impact on a normal person's sleep. For example, if you go to bed at 22:00, then drink coffee before 5pm.

However, different groups of people have varying levels of tolerance to caffeine. For those who already have poor sleep, insomnia, or sleep disorders, it is still advisable to drink less or avoid coffee as much as possible.

2. Population with arrhythmia

Although an increase in heart rate after drinking coffee is a normal phenomenon, it still needs to be taken seriously, especially for people who already have arrhythmia.

Arrhythmia is mainly caused by abnormal electrical conduction of the heart, resulting in irregular, too fast or too slow heartbeat. More than 80% of American doctors recommend patients with palpitations or arrhythmias to quit or reduce their intake of caffeine.

In addition, some studies have shown that for most people, even those with arrhythmia or those at high risk of arrhythmia, although there is no clear threshold for caffeine harm, a daily intake of less than 400 milligrams of caffeine seems safe and may even have a protective effect on arrhythmia; However, for individuals with malignant arrhythmias and high-risk individuals with caffeine sensitive arrhythmias, it is still advisable to avoid caffeine intake as much as possible.

400 milligrams of caffeine is equivalent to no more than 4 cups of pure coffee (150 milliliters per cup). If it is purchased coffee, the number of cups can be calculated by comparing the caffeine content per cup on the packaging label; If it is a small packet of 1.8-2g instant coffee, generally no more than 5 bags per day.

3. People with stomach diseases

Coffee can stimulate the gastrointestinal tract and increase the secretion of stomach acid.

For people with normal stomach function, this will not affect their health. But for people who already have stomach problems, such as gastric ulcers, excessive gastric acid secretion, and gastroesophageal reflux disease, frequent or excessive consumption of coffee may lead to symptoms such as nausea, vomiting, acid reflux, and heartburn.

4. Patients with irritable bowel syndrome

Irritable bowel syndrome is a common functional bowel disease, and patients may experience frequent diarrhea and constipation.

Caffeine can stimulate the secretion of gastric acid and cholecystokinin in the digestive system, thereby promoting colon motility and causing symptoms such as diarrhea. In general, patients with irritable bowel syndrome are more sensitive to caffeine, and drinking it may increase symptoms of gastrointestinal discomfort and diarrhea. Reducing caffeine intake can lower the incidence of symptoms related to irritable bowel syndrome.

5. Osteoporosis population

The caffeine, tannic acid and other components in coffee can indeed affect calcium absorption, and caffeine diuresis can increase calcium loss, but this has little effect on healthy people. A study suggests that caffeine has minimal negative effects on calcium absorption, and only 1-2 tablespoons of milk can completely counteract it.

Based on a large amount of population data, food safety regulatory agencies such as the European Food Safety Agency, the US Food and Drug Administration, Health Canada, and the Australian and New Zealand Food Standards Agency believe that a daily intake of caffeine within 400 milligrams for healthy adults will not have adverse effects on cardiovascular function, behavior, reproduction and development, bone health, and there is no risk of acute poisoning. So, healthy people don't have to worry about drinking coffee causing osteoporosis.

However, for individuals who already suffer from osteoporosis, the "Chinese Expert Consensus on the Diagnosis, Treatment, and Management of Osteoporotic Pain in the Elderly (2024 Edition)" recommends avoiding excessive consumption of coffee.

6. Glaucoma patients

Studies have shown that caffeine in coffee can cause abnormal increase in intraocular pressure in glaucoma patients, which is a risk factor for the development of glaucoma. Elevated intraocular pressure can cause damage to the optic nerve and visual function, and in severe cases, can lead to blindness.

Therefore, glaucoma patients should avoid drinking high caffeine beverages such as coffee in their daily lives to prevent further damage to the eyes caused by increased and fluctuating intraocular pressure.

7. Children and adolescents

The currently recommended safe intake of caffeine for children and adolescents internationally is no more than 2.5-3 milligrams per kilogram of body weight. That is to say, for children and adolescents weighing 40 kilograms, the intake of caffeine is 100-120 milligrams, which is about one cup of coffee. Of course, it's better not to drink.

This is because children who are in the growth and development stage have weaker ability to metabolize caffeine than adults, which not only affects sleep but also physical development.

The "Chinese Children and Adolescents Snack Guide (2018)" also mentions that foods containing caffeine can have negative effects on children's brain development and function. Therefore, children aged 12 and under are prohibited from consuming caffeine and do not drink caffeinated beverages such as strong tea and coffee.

8. Pregnant and lactating women

According to the Scientific Consensus on Coffee and Health, it is not recommended for pregnant women to drink coffee, and if consumed, no more than 2 cups per day. Although institutions such as Health Canada, the American College of Obstetricians and Gynecologists, and the American Maternity Association believe that coffee consumption during pregnancy should be moderate (no more than 150-300mg of caffeine per day, about 2 cups), pregnant women should not be encouraged to drink coffee.

Therefore, for women who do not have the habit of drinking coffee regularly, it is recommended not to drink coffee during pregnancy and lactation; For women who have a habit of drinking coffee regularly, it is best to limit their coffee consumption.

Summary

Although drinking coffee is beneficial for health, it should also be limited. The Scientific Consensus on Coffee and Health recommends that the daily intake of caffeine for ordinary adults should be controlled within 400 milligrams.

Different groups of people have varying levels of tolerance to caffeine. It is recommended that the 8 groups of people mentioned in the article, as well as those who are sensitive to caffeine, limit or avoid caffeine intake according to their own circumstances.

References

[1]Zhou H, Nie J, Cao Y, et al. Association of daily sitting time and coffee consumption with the risk of all-cause and cardiovascular disease mortality among US adults. BMC Public Health. 2024; 24(1):1069. Published 2024 Apr 17. doi:10.1186/s12889-024-18515-9

[2] Zhang Manyu, Fan Hongling, Zhai Wenchao Research progress on the correlation between caffeine and arrhythmia [J]. Journal of Integrated Traditional Chinese and Western Medicine in Cardiovascular and Cerebrovascular Diseases, 2024, 22 (8): 1433-1437

[3] Qin Xian, Song Jun, Hou Xiaohua Research progress on lifestyle and dietary management of irritable bowel syndrome [J]. Gastroenterology, 2018, 23 (7): 436-439

[4]Heaney, R P. “Effects of caffeine on bone and the calcium economy.” Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association vol. 40,9 (2002): 1263-70. doi:10.1016/s0278-6915(02)00094-7

[5] Chinese Society for Food Science and Technology Scientific consensus on caffeine [J/OL]. Chinese Journal of Food Science: 1-6 [2400-05-17] http://kns.cnki.net/kcms/detail/11.4528.TS.20240416.1351.007.html.

[6] Xiong Haibo, Yi Hong, Liu Xin, Dai Yubing Meta analysis of the effect of caffeine on intraocular pressure in glaucoma patients [J]. Journal of Laboratory Medicine and Clinical Medicine, 2015, 12 (16): 2362-2363

[7] Cao Huijuan, Liu Jianping A systematic review of the correlation analysis between caffeine intake during pregnancy and miscarriage [J]. Chinese Journal of Practical Gynecology and Obstetrics, 2014, 30 (12): 945-950

[8]Lisowska A, Kasiak P, Rząca M. Assessment of caffeine intake in groups of pregnant and breastfeeding women: A cross-sectional analysis. Clin Nutr ESPEN. 2023 Oct; 57:151-157.  doi: 10.1016/j.clnesp.2023.06.041. Epub 2023 Jun 29. PMID: 37739650.

Planning and production

Review | Ruan Guangfeng, Deputy Director of Kexin Food and Health Information Exchange Center, Member of the Health Communication Branch of the Chinese Preventive Medicine Association

Planning | Fu Sijia

Editor in Chief | Wang Mengru

Pengpai | Science Popularization China