1. The benefits of drinking coffee Caffeine can stimulate the central nervous system and muscles, so it can refresh the spirit, enhance the thinking ability and restore muscle fatigue. Acting on the cardiovascular system can improve heart function, relax blood vessels and promote blood circulation. For the gastrointestinal system, it can help digestion and help the decomposition of fat. 1. Caffeine, which helps to lose weight, can really accelerate the decomposition of fat, but at the same time, it is more necessary to rely on muscle exercise to convert excess fatty acids into heat energy for consumption. If there is no coordinated exercise, excess fatty acids will flow back along the blood stream and accumulate fat again. Therefore, after drinking coffee, you need to be active at the same time to play a real weight loss effect! Coffee itself has calories, but not much. The main calories are the creamer and sugar you add when you drink coffee. 2. Antioxidant capacity A few days ago, a research report pointed out that coffee contains four times more antioxidants than tea, which is more resistant to cardiovascular diseases, and coffee itself also conforms to the principle of antioxidants, and it is dark and bitter. Each coffee contains different antioxidants because of the brewing method. For example, American coffee contains the least antioxidant, while Espresso contains the most antioxidant. After adding creamer to coffee, its antioxidant effect will not be affected. 3. Improve dry eyes Foreign reports point out that coffee drinkers are significantly less likely to suffer from dry eyes than non-coffee drinkers. This is mainly related to the purine component in coffee (eye drops containing purine can stimulate glands to secrete liquid, which has a certain protective effect on eyes). This is of course good news for computer people who love to drink coffee, but it should be noted that coffee itself has diuretic effect, even if some of its ingredients have protective effect, people who have already suffered from dry eye and those who have taken any medicine containing diuretic ingredients must be prohibited from taking caffeinated drinks, so as not to aggravate the loss of water in the body. 4. It can relieve the headache caused by not sleeping well all night, or the pain caused by vasoconstriction on the temple side. The pain caused by these non-organic factors can be relieved by coffee, but it must be drunk in the morning or at noon (note: it is forbidden from afternoon to night). 5. The amount of coffee is good for the human body, but you can't drink too much coffee. It is advisable to have no more than 2 cups a day. For people who are prone to nervousness and anxiety, drinking too much may be harmful. 6. When drinking coffee, it is best to drink coffee after breakfast and lunch, because it can promote gastrointestinal peristalsis, help digestion, decompose high-calorie and high-fat foods that you eat, and will not cause irritation to the stomach like drinking coffee on an empty stomach. It is best not to drink coffee after dinner, for fear that it will affect your sleep. If you want to stay up all night by drinking coffee, you may drink too much unconsciously, which is not good for your health. 2. Disadvantages of drinking coffee 1. Adding caffeine when you are nervous will help improve your alertness, sensitivity, memory and concentration. But if you drink more coffee than you are used to, you will have the same dose of stimulants, which will cause nervousness. For people who tend to have anxiety disorders, caffeine can make the symptoms of sweaty palms, palpitations and tinnitus worse. 2. Aggravating hypertension Caffeine is often combined with other simple painkillers because of its analgesic effect. However, if you take it in large quantities for a long time, if you already have hypertension, using a large amount of caffeine will only make your situation worse. Because caffeine alone can raise blood pressure, and if it is combined with emotional tension, it will have a dangerous multiplication effect. Therefore, people at risk of hypertension should especially avoid drinking caffeinated drinks when working pressure is high. Some people who have the habit of drinking coffee all the year round think that they are immune to the effect of caffeine, but this is not the case. A study shows that after drinking a cup of coffee, the blood pressure can rise for as long as 12 hours. 3. Caffeine, which induces osteoporosis, has a good diuretic effect. If you drink a lot of coffee for a long time, it will easily lead to bone loss, which will have an adverse effect on the preservation of bone mass. For women, it may increase the threat of osteoporosis. But the premise is that people who don't get enough calcium in their food at ordinary times, or people who don't move often, and women after menopause, lose calcium due to lack of estrogen, which, together with a lot of caffeine, may pose a threat to bone. If you can enjoy it in a reasonable amount, you can still do it without choking. 3. These people drink coffee carefully 1. Caffeine in patients with liver disease will prolong the time for caffeine to die in the body. Generally, it takes 2 hours for normal adults to metabolize caffeine, but it may take 4-5 hours for patients with liver disease or liver insufficiency. Therefore, patients with liver disease must be careful when drinking coffee, and it is best not to drink it after evening to avoid affecting sleep due to long metabolism time, and it is best not to exceed 1 cup a day. 2. The reason why coffee for patients with digestive diseases is among them is that tannic acid can stimulate gastric acid secretion, which must be avoided if it is a patient with acute digestive diseases. After recovering, if you drink coffee occasionally, it is best to use it after meals to avoid drinking coffee on an empty stomach. 3. Pregnant women Many women will pay special attention to all the food they eat after pregnancy. Of course, beverages containing caffeine are also listed as one of the taboos. This is mainly due to the slow metabolism of caffeine in pregnant women, which will prolong the time that caffeine stays in the body, and it will take eight or nine months for the fetus in the abdomen to clear caffeine from the blood through metabolism. 4. Children's half-life of caffeine metabolism will be prolonged due to the incomplete development of children's liver and kidney and poor detoxification ability, so generally speaking, children under 12 need to ban caffeine intake. Even Europeans and Americans who drink coffee as boiling water all day have strict restrictions on children drinking coffee.