咖啡真的不健康吗？Is coffee really unhealthy?

原创 李钰峥 食品与生活

咖啡是一种广泛流行的饮料，用经过烘焙的咖啡豆制成，通常为热饮，但也可以作为冷饮（冰咖啡）。咖啡豆是茜草科常绿小乔木——咖啡树的果仁，原产地埃塞俄比亚的咖法省高原地区。大约在11世纪时，人们开始用水煮咖啡作为饮料，17世纪传至欧洲和亚洲。

咖啡作为一种饮品，可谓功成名就。毫不夸张，它已经成为很多人的一种执念。我喜欢咖啡，又不喜欢咖啡。我不懂咖啡入口的酸苦，却又贪婪它的气味，抑或说，我爱的是喝咖啡的感觉。

咖啡之所以能够提神醒脑，源于其主要功效成分——咖啡因。咖啡因即咖啡果的次生代谢物（在植物的生长过程中，体内会出现用作自我保护的次生代谢物）。人脑中枢有一对负责反馈疲劳信号的伙伴，即腺苷与腺苷受体。当人感到疲劳，这对伙伴便会一起向大脑报告，大脑随即发出需要休息的信号。咖啡因的化学结构与腺苷非常相似。如果这时喝完一大杯咖啡，咖啡因就会伪装成腺苷，抢夺并占据腺苷受体，大脑便无法收到身体疲劳的信号，不会产生睡意。与此同时，还会感到双手变冷，肌肉紧张，兴奋甚至心跳加速。这是由于咖啡因插足而引起的异常被脑垂体发现，以为机体出现突发状况，于是紧急调兵遣将，刺激产生肾上腺素。

咖啡因为这个神奇之处成为了很多人的心头好，但也让很多人觉得它像毒品，似乎不健康却又戒不掉。咖啡真的不健康吗？

咖啡和心血管疾病、癌症

适量喝咖啡对心血管健康是有好处的，并且可以降低死亡率。

目前学术界已经确定：适量喝咖啡对心血管健康是有好处的，并且可以降低死亡率。此外，有些人担心喝咖啡会增加患癌的风险。虽然咖啡豆在烘焙过程中确实会产生丙烯酰胺（一种致癌化合物），但抛开剂量谈作用无疑是不明智的。有研究显示，丙烯酰胺的致癌剂量大约为每天每千克体重摄入2.6～16微克。也就是说，一个体重为50千克的成年人，需要每天喝至少10千克咖啡，才会达到致癌剂量。

咖啡和抑郁症

喝咖啡的人患抑郁症的风险较低，自杀的可能性也大大降低。

在当代紧张快速的生活节奏下，每个人的头顶上似乎都有一块乌云，抑郁症患者也越来越多。抑郁症是世界上最常见的精神障碍。哈佛大学于2011年进行的一项研究表明，喝咖啡的人较不喝咖啡的人患抑郁症的风险降低了20％，同时，一项追踪研究发现，每天喝四杯及以上咖啡的人，自杀的可能性降低了53％。

咖啡和“老年痴呆”

咖啡可以预防阿尔茨海默症和帕金森综合征。

阿尔茨海默症和帕金森综合征是两大常见的神经退行性疾病，目前在医学上都是不能完全治愈的。流行病学研究发现，咖啡摄入量增加与阿尔茨海默症风险降低相关。同时，喝咖啡的人患帕金森综合征的风险也较低。

咖啡和糖尿病

喝咖啡的人患2型糖尿病风险较低。

糖尿病是一种由于胰岛素分泌缺陷或胰岛素作用障碍所致，并以高血糖为特征的代谢性疾病，根据发病原因分为两种类型。流行病学的最新证据表明，多喝咖啡可以降低2型糖尿病和血糖代谢紊乱的风险。

咖啡和钙流失

会，但不用太担心。

咖啡导致的钙流失是由于咖啡因有短时的利尿作用，通过排尿会带走一部分矿物质，包括钙。然而，每杯咖啡中的咖啡因只会增加2～3毫克的钙流失，因而日常喝咖啡并不用太担心钙流失的问题。如果你喝的是奶咖就更不用担心了，牛奶带给你的钙远大于那些流失的钙。

改善有方

❶ 咖啡的疾病预防作用只针对普通健康人群, 并不包括心血管疾病、糖尿病、心脏病、高血压等患者，暂时没有证据表明咖啡对疾病有治疗效果。此外，本文引用的许多研究都是观察性的，即只研究了喝咖啡与疾病结局之间的关联，但没有证明因果关系。

❷ 孕妇应当减少或严格限制咖啡的摄入。

❸ 有一些证据表明，咖啡因代谢缓慢人群喝咖啡会增加心脏病发作的风险。

总之，如果你没有喝咖啡的习惯，不喝也无妨，毕竟凡事有利有弊，如果你喜欢喝咖啡而且已经养成习惯，不妨尽情享受咖啡带来的美妙。咖啡不是神药，但适量喝咖啡也是一种健康的生活方式。

原标题：《咖啡真的不健康吗？》

Original by Li Yuzheng Food and Life

Coffee is a widely popular beverage made from roasted coffee beans, usually served as a hot drink but also as a cold drink (iced coffee). Coffee beans are the nuts of the coffee tree, a small evergreen tree in the Rubiaceae family, native to the highlands of Kaffa Province, Ethiopia. Around the 11th century, people began using boiled coffee as a beverage, which spread to Europe and Asia in the 17th century.

Coffee, as a beverage, can be said to have achieved great success. Without exaggeration, it has become a obsession for many people. I like coffee, but I don't like coffee. I don't understand the bitterness of coffee in the mouth, but I am also greedy for its aroma, or rather, what I love is the feeling of drinking coffee.

The reason why coffee can refresh the mind is due to its main active ingredient - caffeine. Caffeine is a secondary metabolite of coffee fruit (a self-protection secondary metabolite that appears in the body during plant growth). The central nervous system of the human brain has a pair of partners responsible for feedback of fatigue signals, namely adenosine and adenosine receptors. When a person feels tired, these partners will report to the brain together, and the brain will immediately send a signal that they need to rest. The chemical structure of caffeine is very similar to adenosine. If you finish a large cup of coffee at this time, caffeine will disguise itself as adenosine, seize and occupy adenosine receptors, and the brain will not receive signals of physical fatigue and will not produce drowsiness. At the same time, you may also feel your hands getting cold, muscles tense, excited, and even your heart beating faster. This is due to the abnormality caused by caffeine being inserted, which was discovered by the pituitary gland, thinking that the body had an emergency situation. Therefore, emergency troops were mobilized to stimulate the production of adrenaline.

Coffee has become a favorite of many people because of its magical properties, but it also makes many people feel like it's like a drug, seemingly unhealthy yet unable to quit. Is coffee really unhealthy?

Coffee and cardiovascular disease, cancer

Moderate coffee consumption is beneficial for cardiovascular health and can reduce mortality rates.

Currently, the academic community has confirmed that moderate coffee consumption is beneficial for cardiovascular health and can reduce mortality rates. In addition, some people are concerned that drinking coffee may increase the risk of cancer. Although coffee beans do produce acrylamide (a carcinogenic compound) during the roasting process, it is undoubtedly unwise to talk about its effects without considering the dosage. Studies have shown that the carcinogenic dose of acrylamide is approximately 2.6-16 micrograms per kilogram of body weight consumed per day. That is to say, an adult weighing 50 kilograms needs to drink at least 10 kilograms of coffee per day to reach the carcinogenic dose.

Coffee and Depression

People who drink coffee have a lower risk of depression and a significantly reduced likelihood of suicide.

In the current fast-paced and tense lifestyle, there seems to be a dark cloud above everyone's head, and there are also more and more patients with depression. Depression is the most common mental disorder in the world. A study conducted by Harvard University in 2011 showed that people who drink coffee have a 20% lower risk of depression compared to those who do not drink coffee. Additionally, a follow-up study found that people who drink four or more cups of coffee per day have a 53% lower likelihood of suicide.

Coffee and 'senile dementia'

Coffee can prevent Alzheimer's and Parkinson's syndrome.

Alzheimer's disease and Parkinson's syndrome are two common neurodegenerative diseases that are currently incurable in medicine. Epidemiological studies have found that an increase in coffee intake is associated with a reduced risk of Alzheimer's disease. Meanwhile, coffee drinkers also have a lower risk of developing Parkinson's syndrome.

Coffee and diabetes

Coffee drinkers have a lower risk of type 2 diabetes.

Diabetes is a metabolic disease characterized by hyperglycemia, which is caused by insulin secretion defect or insulin dysfunction. The latest epidemiological evidence shows that drinking more coffee can reduce the risk of type 2 diabetes and glucose metabolism disorder.

Coffee and calcium loss

Yes, but don't worry too much.

The calcium loss caused by coffee is due to the short-term diuretic effect of caffeine, which takes away some minerals, including calcium, through urination. However, the caffeine in each cup of coffee only increases calcium loss by 2-3 milligrams, so there is no need to worry too much about calcium loss when drinking coffee in daily life. If you are drinking milk coffee, there is no need to worry, as milk provides you with much more calcium than the lost calcium.

Improvement is effective

The disease prevention effect of coffee is only aimed at ordinary healthy people, not including patients with cardiovascular disease, diabetes, heart disease, hypertension, etc. There is no evidence that coffee has therapeutic effect on diseases for the time being. In addition, many of the studies cited in this article are observational, that is, they only studied the association between coffee consumption and disease outcomes, but did not prove a causal relationship.

Pregnant women should reduce or strictly limit their intake of coffee.

There is some evidence to suggest that people with slow caffeine metabolism who drink coffee have an increased risk of heart attack.

In short, if you don't have the habit of drinking coffee, it's okay not to drink it. After all, there are pros and cons to everything. If you enjoy drinking coffee and have developed a habit, you can enjoy the beauty it brings to yourself. Coffee is not a miracle drug, but drinking coffee in moderation is also a healthy lifestyle.

Title: Is Coffee Really Unhealthy