Caffeine is the main raw material of coffee, which can stimulate the liver, make people think clearly and reduce fatigue. However, the side effects of caffeine can not be ignored. The following are the "seven deadly sins" announced by experts: people who drink a lot of coffee tend to become neurotic; Easy to cause dry skin; Easy to make teeth yellow; The possibility of a heart attack is 50% higher; Caffeine will increase the loss of calcium; Bladder cancer and other cancers of urinary organs are closely related to the amount of coffee consumed. The seventh deadly sin is the most serious: experts suspect that caffeine can lead to early threatened abortion in pregnant women. Of course, for coffee, we don't have to be "scared." After all, proper drinking is good for human health. Only excessive drinking of coffee will be harmful to human health. You may ask: How much coffee is excessive? In fact, it all depends on the individual's tolerance and habits. Coffee may keep you awake at night, or it may raise your blood pressure. However, Professor Martin, director of the coffee research institute of Vanderbilt University in the United States, recently said that coffee contains hundreds of healthy ingredients, which can resist liver injury, various cancers, asthma, heart disease and paralysis. He pointed out that it is beneficial to drink 2-4 cups of coffee every day. People who don't drink coffee are more likely to suffer from these diseases than those who drink coffee. Studies in recent 20 years have confirmed that caffeine is an effective component in coffee, which can activate the central nervous system, and can be used to make long-term analgesic drugs, which can resist drowsiness, colds, asthma and edema. Its side effects are addiction, insomnia, nervousness and high blood pressure. Studies have shown that coffee contains anti-dementia substances, which can reduce the impact of harmful substances on the body and help prevent some diseases. Scientists say that when oxygen in the human body is mixed with other chemicals, it will form harmful substances that blindly destroy cells and body tissues, which is the cause of heart disease, vascular disease, tumor, decline of immune mechanism and neurasthenia. The research results of the American Coffee Institute show that coffee contains four times as many anti-dementia substances as tea. Nutrition plays a major role in strengthening the body's disease prevention mechanism. The substances that can resist dementia include vitamin E, vitamin C, carotene in soybean, red wine, some seasonings, fruits, onions, olives and so on. Roasted coffee beans are more resistant to dementia, and this substance in decaffeinated coffee will not be weakened or destroyed. At the same time, experts point out that drinking a cup of coffee in the morning can refresh you, and drinking coffee during the day can refresh you. So coffee can be a little stronger at this time. It is best to have a little coffee after dinner or in the evening. Coffee is recognized as a healthy drink, but drinking coffee should be controlled for a certain time. Coffee or tea should not be used with meals, but should be drunk after meals. When drinking coffee, whether it is hot or cold, you should drink some boiled water. First of all, it can remove the peculiar smell of the mouth to get a better taste; Second, because coffee has diuretic effect, drinking more white water can improve urination and protect renal function, and you don't have to worry about getting angry when drinking coffee. Black coffee has always been called "the messenger of health", and its main effects on health are as follows: 1. Caffeine can stimulate the central nervous system, make the mind clearer, have abundant thinking ability, concentrate and improve work efficiency; 2. Caffeine can make muscles contract freely and improve motor function. 3. appetizing and digestion caffeine stimulates gastrointestinal secretion of gastric acid, which can promote intestinal peristalsis, help digestion, prevent gastroptosis and have a rapid laxative effect. 4. Liqiao dehumidification caffeine can promote renal function, discharge excess sodium ions in the body, increase urination and improve abdominal distension and edema. 5. The linoleic acid contained in the coffee for promoting blood circulation and removing blood stasis has the functions of hemolysis, preventing thrombosis, enhancing vasoconstriction, relieving migraine and reducing the probability of stroke. 6. Pingfei Dingchuan Caffeine can inhibit parasympathetic nerve and reduce asthma attacks. 7. Dry deodorized caffeine contains tannin, which has a strong adsorption capacity for taste. If your room has just been renovated, make a pot of coffee indoors, and the taste will be quickly removed. 8, drinking coffee can protect the liver and hangover. 9, coffee can lose weight The best time to drink coffee to lose weight is 30 minutes after lunch to 1 hour and before going to work, taste a cup of rich sugar-free black coffee, with walking, can promote fat burning. 10, black coffee can effectively improve hypotension. 1 1, black coffee has antioxidant effect, which helps to prevent cancer and resist aging. Coffee, we have been talking about it from an emotional point of view. Today, let's take a look at its essence. 1. Coffee contains some nutrients. Nicotinic acid in coffee contains vitamin B, and roasted coffee beans have higher content. But also free fatty acids, caffeine, tannic acid and so on. 2. Coffee is good for the skin. Coffee can promote metabolic function, activate digestive organs and play a great role in constipation. Bathing with coffee powder is a kind of hyperthermia, which has the function of losing weight. 3. Coffee has the function of relieving alcoholism. Drinking coffee after drinking will quickly oxidize acetaldehyde converted by alcohol, decompose it into water and carbon dioxide and excrete it. 4. Coffee can relieve fatigue. To eliminate fatigue, we must supplement nutrition, rest and sleep, and promote metabolic functions, and coffee has these functions. Three cups of coffee a day can prevent gallstones. For caffeinated coffee, it can stimulate gallbladder contraction and reduce cholesterol which is easy to form gallstones in bile. Recently, researchers at Harvard University found that men who drink two or three cups of coffee a day have a lower risk of gallstones than 40%. 6. Drinking coffee regularly can prevent radiation injury. Radiation hazards, especially electrical radiation, have become the prominent pollution at present. Baba's Indian atomic researchers reached this conclusion in mouse experiments and said it can be applied to humans. 7. The health function of coffee. Coffee has the functions of resisting oxidation, protecting the heart, strengthening bones and muscles, benefiting the waist and knees, stimulating appetite, promoting eating, reducing fat and digestion, inducing resuscitation and removing dampness, promoting blood circulation and removing blood stasis, calming wind and relieving spasm. 8. The influence of coffee on mood. Experiments show that the average person absorbs 300 mg (about 3 cups of brewed coffee) every day, which will have a good influence on a person's alertness and mood. The following six kinds of people should not drink coffee: suffering from hypertension, coronary heart disease, arteriosclerosis and other diseases-drinking coffee for a long time or in large quantities will cause cardiovascular diseases. Older women-coffee can reduce calcium and cause osteoporosis. After menopause, women need to supplement ten times as much calcium every day. Patients with stomach trouble-drinking too much coffee will make stomach trouble worse. Pregnant women-drinking too much coffee can lead to fetal malformation or miscarriage. Vitamin B 1 deficiency-vitamin B 1 can keep the balance and stability of the nervous system, and coffee can destroy it. Cancer patients-drinking too much coffee is dangerous for normal people.