The study also found that drinking a proper amount of caffeine every day can accelerate metabolism, promote digestion, improve constipation, boost the spirit and relieve pain. On the psychological level, drinking coffee is a kind of enjoyment, which can also relieve stress, relax mood, stimulate gastrointestinal peristalsis and have a laxative effect. Drinking after meals will promote the secretion of gastric juice, so it will help digestion. Medical research shows that coffee beans contain nutrients such as sugar, protein, fat, potassium, crude fiber and water. In addition, coffee also contains caffeine, tannic acid, alkaloids and other ingredients beneficial to human health. Many studies have pointed out that drinking coffee in moderation, that is, drinking two to four cups a day, can stimulate the sympathetic nervous system and produce refreshing and fatigue-relieving effects; It can also relax blood vessels, promote blood circulation, prevent cardiovascular diseases, help head artery to contract, and help relieve migraine. Although coffee has many advantages, it is undeniable that coffee is not without its disadvantages, and drinking too much will also cause harm to the body. Studies have found that "iron deficiency anemia" is a common problem in countries that drink a lot of coffee, because coffee will affect our body's absorption of iron. Caffeine contained in coffee can stimulate our central nervous system, cause anxiety and insomnia, stimulate stomach acid and increase fatty acids and glucose in the blood. Studies abroad have found that women who drink too much coffee will cause bone loss; Some studies show that people with hypertension should drink less coffee. If they drink two or three cups of coffee every day, their blood pressure will rise. In addition, some studies have pointed out that drinking too much coffee will lead to an increase in bad sterols. Later, it was proved that it was not caffeine but coffee soybean oil that caused the increase of serum cholesterol. It is not difficult to remove soybean oil. Just use a filter paper when making coffee, and the oil can be filtered out. The study also found that excessive consumption of caffeine can discolor teeth, make them more prone to arthritis, stimulate the release of bile hormones and promote gallbladder contraction. For people with gallstones and colic, drinking coffee may aggravate the symptoms. Caffeine can also increase the resistance of carotid artery, reduce the blood flow needed for fetal growth, and affect the supply of nutrients and oxygen, which may be the reason why coffee leads to baby weight loss or pregnant women abortion. It is worth noting that drinking too much coffee may lead to cardiovascular diseases. The American Journal of Clinical Nutrition published a study. There are 3000 men and women who drink more than 200ml of coffee every day. It was found that the inflammatory indexes of coffee drinkers, including protein C, tissue necrosis factor and white blood cell count, were significantly higher than those of non-coffee drinkers. The more coffee they drink, the higher the index rises. The higher the inflammatory index, the higher the risk of cardiovascular disease in the future. Therefore, people with arrhythmia or cardiovascular diseases are advised to drink less coffee. In addition, people with low potassium ion should not drink coffee, because coffee has diuretic effect, which will excrete potassium ion and affect renal function. Too much coffee can be poisoned, just like drugs and food, too much coffee can be poisoned. Although drinking coffee is good for your health, from a medical point of view, it is best to drink less if you don't drink coffee, because drinking too much coffee is easy to become addictive. Don't drink too much. Drinking more than 1000cc every day has reached the poisoning standard, and even anesthetic has no effect. For health, she gradually lost weight, and now she only drinks about 700 cc a day. Coffee, like medicine and food, can lead to poisoning in excess. A while ago, there was a case of an artist drinking coffee to lose weight, and the side effects were very serious. Drinking caffeine in large quantities every day, exceeding 5g to10g (about drinking more than 45 cups 150cc of ground coffee or more than 23 cups of 300cc mugs every day), may cause general convulsions, coma, severe brain edema, hypokalemia, arrhythmia and cardiac paralysis, which may lead to death. Not only coffee, but also caffeinated drinks on the market should not be consumed excessively every day. If you consume more than 500 mg to 1000 mg (one gram) of caffeine every day, drink more than 4 cups of ground coffee every day, or more than 2 cups of 300cc coffee cups, you will have mild symptoms of caffeine poisoning, such as fidgeting, anxiety, irritability, palpitation, nausea, and increased diuretic effect of urine. Drinking a lot of coffee is easy to cause poisoning, and drinking caffeine for a long time can also be addictive. The greater the daily intake of caffeine, the greater the chance of addiction and the faster the speed. Once coffee addicts don't drink coffee, they will have withdrawal symptoms such as headache, general fatigue and yawning, but as long as they are patient, they can return to normal without drinking coffee for a few days. Tips for drinking coffee: Do not drink more than 4 cups of ground coffee (such as American coffee, latte and cappuccino) every day to prevent mild poisoning. If you have symptoms such as irritability, anxiety, irritability, palpitation and nausea after drinking coffee, it is best not to drink caffeinated drinks such as cola and tea on the same day. According to the recent research report in 2004, caffeine will be absorbed by the baby through the placenta and enter the baby's body, which is harmful to the baby's brain and heart. Therefore, pregnant women had better not drink coffee. Teenagers under 18 are still developing, so it is better to drink less caffeinated drinks. Drinking coffee in the morning helps to clear your head, but don't drink it on an empty stomach to avoid hurting your stomach. People with duodenal ulcer should avoid drinking coffee on an empty stomach. Don't smoke or drink immediately after drinking coffee, otherwise it will promote blood circulation and increase cardiovascular burden, which is not conducive to heart health. Although caffeine can boost the spirit, drinking too much or drinking too much will make people impatient and weaken their understanding. It is best to add cream to coffee, which can reduce the irritation to the stomach, but it is necessary to control the intake of sugar and avoid obesity. If people with gallstones drink too much coffee, they may feel pain because caffeine stimulates gallbladder contraction. Therefore, people with gallstones had better not drink coffee. Drinking time is the key. For healthy people, the biggest disadvantage of caffeine is that it may make people like to drink it constantly. Coffee has both advantages and disadvantages. How to learn from its strengths and avoid its weaknesses? This must be discussed from three aspects: time, habit and intake of coffee. Time for coffee is very important. Because drinking coffee an hour before meals will not reduce the absorption of iron, but drinking coffee an hour after meals will reduce the body's ability to absorb iron. Drinking coffee on an empty stomach will stimulate the stomach and cause discomfort. In order not to stimulate the stomach and reduce the absorption of iron, it is recommended to drink coffee 30 minutes after meals. As for drinking in the morning or afternoon? It varies from person to person, because everyone has different tolerance for coffee. Some people can't sleep at night after drinking in the afternoon, and some people can sleep before going to bed. She believes that coffee lovers should control their time of drinking coffee, so that they don't have to lose sleep in order to enjoy mellow coffee. Concentration affects health In the habit of drinking coffee, different brewing methods will affect the absorption of iron. A cup of coffee will reduce the iron absorption rate from 5.88% to 1.64%. If drinking instant coffee is worse, the iron absorption rate will be reduced to 0.96%, and when the coffee concentration doubles, the iron absorption rate will be reduced to 0.53%. In addition, the ingredients of traditional creamer are mostly vegetable oil, not dairy products. It is suggested to replace creamer with fresh milk and milk powder to supplement calcium that may be lost when drinking coffee. It is worth noting that people with poor gastrointestinal system should not add too much polysaccharide to avoid irritation to the stomach. People who have a bad stomach should drink less coffee after noon, so as not to cause stomach upset. Many people have trouble putting coffee in the refrigerator. They like to buy a lot of coffee beans at a time, or grind 300 to 400 grams of coffee beans into powder and put them at home, which will easily deteriorate coffee and produce carcinogens. In hot and humid climate, coffee beans are prone to produce ochratoxin at room temperature. For example, some coffee shops expose coffee beans to the air, and the residual ochratoxin in coffee beans can easily reproduce and produce ochratoxin at sufficient humidity and room temperature. People who eat too much ochratoxin will not only cause kidney disease, but also have the risk of miscarriage, liver injury and cancer in animal experiments. In order to avoid eating ochratoxin by mistake, it is best to seal inexhaustible coffee beans or coffee powder and store it safely in the refrigerator. Coffee beans are easy to deteriorate. It is best to put coffee beans or coffee powder in the refrigerator and drink it within one month, otherwise the coffee will deteriorate and produce carcinogens. The best way is to take the beans out of the refrigerator and grind them every day when you want to drink coffee, and brew them immediately. The influence of coffee on human body The benefits of coffee Can you lose weight and fat by drinking coffee? Dietitians say that drinking coffee can speed up the metabolic rate of the human body by 3 to 4%, increase the rate of calorie consumption, and help control weight. But only if you drink black coffee. If you add sugar and cream, a packet of sugar packets and cream balls has about 50 calories, and 6 cups of coffee a day has 300 calories. If you don't exercise properly, you will get fat in the long run. Analgesic caffeine has analgesic effect, such as caffeine contained in cold syrup. People with migraine can drink coffee to solve this problem, and the effect is good. But it's best to drink it when there are signs, because it takes 10 to 30 minutes after drinking. The disadvantages of coffee-induced breast cancer Caffeine will stimulate the breast, lead to breast fibrocyst, and even develop into breast cancer.