In fact, the function of coffee can be divided into short-term function (immediate reflection of drinking it) and long-term function (that is, drinking coffee for a long time) to discuss. The short-term effect of drinking coffee (the immediate reflection of drinking coffee) is clear, and you can find the answer by your own feelings without relying on any research.
There is no doubt that coffee (caffeine) has a refreshing effect. But its refreshing effect varies from person to person. Some people are sensitive to caffeine, and the refreshing effect is particularly obvious, which may even cause insomnia or difficulty falling asleep. Some people, especially those who often drink coffee, are not so sensitive, and sometimes they don't even feel the obvious refreshing effect. I belong to the latter situation, even if I drink coffee before going to bed at night, it will not affect my normal deep sleep. After drinking coffee, I can't feel the obvious refreshing effect, but coffee is good for me-it makes me feel more energetic and energetic. But is this effect a caffeine effect or a psychological (dependence) effect? It's really hard to identify, so don't identify it. Drinking a glass of white water or other drinks will not have the same effect.
Some people worry that "coffee will not only excite the forebrain, but also damage the concentration to a certain extent, so it will affect the thinking ability." I don't think it's like Xu, and research shows that coffee doesn't affect thinking ability. So, does coffee affect thinking? Don't listen to experts, just try it yourself. Some "experts" say that things that are inconclusive or vary from person to person are not "truth" and not good.
Second, coffee has a definite effect on improving sports ability, and caffeine has a powerful effect, which can improve endurance and sports performance. This is why caffeine is banned by the International Olympic Committee (IOC). According to the regulations of the International Olympic Committee (IOC), when the concentration of caffeine in urine is greater than 12 μ g/ml, it is deemed to be prohibited (i.e. "drug test positive"). Drinking coffee before exercise helps to improve exercise ability.
The long-term effect of drinking coffee (that is, drinking coffee frequently for a long time) is complicated and needs to be confirmed by scientific research. Unfortunately, although there are many studies on coffee, it is often difficult to reach a consistent conclusion. We can only make a rough judgment on many problems.
5. Coffee (and tea) will interfere with the absorption of minerals. Caffeine can interfere with the absorption of calcium, iron, zinc and other minerals in the intestine, so children should not drink coffee. Adults drink coffee, just don't mix it with food.
6. Caffeine can lose weight, but drinking coffee, especially instant coffee, may not be able to lose weight. Caffeine has an exciting effect, which can increase basal metabolism, reduce deep sleep time, increase thermal energy consumption in general and help to lose weight. However, when drinking instant coffee or coffee, if you add something with more energy than sugar, milk or coffee partner, the weight loss effect will be greatly reduced.
7. Mothers drinking coffee will have a negative impact on fetuses and breast-fed babies. The US Food and Drug Administration (FDA) issued a statement advising pregnant or potential pregnant women to reduce caffeine intake. The American Academy of Pediatrics Committee on Drugs recommends that mothers should not consume more than 300 milligrams of caffeine a day.
8. Coffee is not good for patients with gastric ulcer. Because coffee can promote the secretion of gastric juice and increase gastric acid, patients with gastric ulcer should pay more attention when drinking coffee, not exceeding the limit, not to mention drinking coffee on an empty stomach.
9. Coffee can cause calcium loss. Although there is no direct evidence that caffeine can cause osteoporosis, some studies have pointed out that caffeine can increase the calcium excreted in urine, thus increasing the risk of osteoporosis. Therefore, girls who often drink coffee should pay attention to calcium supplementation. In addition, it is reported that increased urinary calcium excretion will increase the risk of kidney calculi's disease. Coffee has anti-cancer effect. There are many reports about coffee and cancer, and most of them support that coffee can prevent cancer. For example, Dr Larsen and Dr Volcker of Karolinska Medical College in Sweden jointly published a report in the American Journal of Gastroenterology, pointing out that drinking coffee is inversely related to the risk of liver cancer. Coffee contains a lot of antioxidants such as chlorogenic acid, which can compete with oxidative stress and prevent the formation of carcinogens. In addition, experiments on animal length also clearly show that coffee and chlorogenic acid can inhibit liver cancer. Of course, there are also some reports that drinking coffee will increase the risk of pancreatic cancer and uterine cysts.
The effect of coffee on heart disease is still unclear. Studies show that a person who drinks five or more cups of coffee a day is twice as likely to have a heart attack as a person who doesn't drink. Studies have also shown that women who drink more than five cups of coffee a week are 32% less likely to suffer from heart disease than women who don't drink coffee or drink less than four cups of coffee a week. Another study showed that there was no correlation between coffee and heart disease. I wonder if these studies have considered the intake of trans fatty acids in instant coffee or coffee partners. It is recognized that excessive trans fatty acids are harmful to the heart.
Third, drinking coffee helps to prevent gout. According to a report by Xinhuanet on May 28, 2007, researchers in the United States and Canada have found that drinking coffee can help reduce the uric acid level in human blood and achieve the effect of preventing gout (however, this effect seems to have nothing to do with caffeine). Comprehensive results: The benefits of coffee itself include refreshing, improving exercise ability (these two functions are clear), anti-cancer, weight loss, and preventing colds. (These functions are not clear enough); The disadvantages of coffee itself include interference with mineral absorption, adverse effects on fetus (these two effects are clear), osteoporosis, kidney calculi, and adverse effects on gastric ulcer. These effects are not clear enough. As for the influence of coffee on cardiovascular and cerebrovascular diseases, there is still great controversy at present, and it is difficult to form a tendentious conclusion.
So if you drink coffee, it is advisable to drink 1 or 2 cups a day, and don't drink too much. Be on high alert for instant coffee or coffee partners.
Trans fatty acids and food additives.