I started drinking coffee a few years ago. At that time, I was staying up late to watch the World Cup football game. At first, the refreshing effect of coffee was very obvious. Later, the refreshing effect of coffee was not so obvious, but drinking coffee has become I get used to it and drink a drink almost every morning (the weekend lecture should be until noon). Sometimes I have a drink when I lecture at night or stay up all night on the Internet. In addition, as long as I patronize the coffee shop, I must drink coffee, and it is often carbon burning. In this way, I drink more than 1 cup of coffee per day on average, most of them are instant coffee.

　　Looking at the ingredients list of instant coffee, it can be seen that the ingredient with the highest content is the non-dairy creamer (or coffee companion), followed by white granulated sugar (or coffee powder), and then coffee powder (or white granulated sugar) ), and finally some supplementary food additives. To be honest, it is this ingredient list that allows me to restrain my desire to drink more coffee. Why?

　　The ingredients of the non-dairy creamer are more complicated, mainly including glucose syrup, hydrogenated vegetable oil and various foods Additives such as emulsifiers, moisture retention agents, antagonists, etc. There are two main health problems worth noting: One is food additives. Even though these big-brand products can use various food additives in accordance with relevant standards, complex and diverse food additives are still a hidden danger to food safety. The second is hydrogenated vegetable oil, which contains "trans fatty acids", Too much trans-fatty acid has a clear harm to the cardiovascular system.

Of course, not only instant coffee contains trans fatty acids, but many processed foods, such as biscuits, bread, snack noodles, cakes, potato chips, snacks, etc., contain more trans fatty acids. In comparison, trans fatty acids in instant coffee are not the most. In a bag of instant coffee (weight 12 to 18 grams), the "vegetable powder" accounts for more than 1/3 (4 to 6 grams), and the "hydrogenated vegetable oil" accounts for more than 1/2 (2 to 3 grams) ), "trans fatty acids" in hydrogenated vegetable oils account for about 1/3 (about 1 gram). Converting it to energy is about 9 kcal. Assuming that the energy intake throughout the day is 2200 kcal, the proportion of trans fatty acids providing energy is 0.4% (9÷2200×100%=0.4%). In the dietary guidelines published in August 2004, the United States issued an advisory that the average daily intake of trans fatty acids should be less than 1% of total energy. Calculated in this way, I drink 1 to 2 cups of instant coffee every day and it will not cause excessive intake of trans fatty acids (of course, if you also eat biscuits, bread, fast food noodles, potato chips and other foods rich in trans fatty acids, Then it is another matter).

　　 has been talking for a long time, but has not talked about the coffee itself. The role of coffee can be divided into short-term effects (immediate response after drinking) and long-term effects (that is, regular long-term drinking of coffee) to discuss. The short-term effect of drinking coffee (immediate reaction after drinking) is relatively clear, and almost no reliance on any research, you can find the answer by your own feelings:

　　 1. Coffee (caffeine) has a refreshing effect, This is beyond doubt. However, the strength of its refreshing effect varies from person to person. Some people are more sensitive to caffeine, and the refreshing effect is particularly obvious. It may even cause insomnia or difficulty falling asleep. Some people, especially those who often drink coffee, are not so sensitive, and sometimes do not even feel the obvious refreshing effect. I myself belong to the latter situation. Even drinking coffee before going to bed at night will not affect normal sleep. After drinking coffee, I can''t feel the obvious refreshing effect, but coffee does work for me-it makes me feel more energetic and more mental. But is this effect a caffeine effect or a psychological (dependence) effect? It''s really difficult to identify, don''t just identify it, anyway, drinking a glass of white water or other beverages will not have the same effect (at least for me In terms of).

　　 Some people worry that “coffee will also damage the concentration of attention to a certain extent while exciting the brain, so it will affect the thinking ability”. I don''t feel this way myself, and some studies have shown that coffee does not affect thinking skills. So, does coffee really affect thinking? Don’t listen to experts, just try it yourself. Some "experts" describe things that are not conclusive or different from person to person as "truth," which is very bad.

　　 2. A similar situation is that the question of whether drinking coffee before sexual activity contributes to sexual performance has also been mixed. Supporters such as the American Overseas Chinese reported that a study conducted by the University of Michigan on 744 couples showed that drinking coffee can not only increase sexual desire but also reduce the chance of impotence (People''s Daily reported on January 9, 2006) . Opponents such as "Life Times" published on September 09, 2008, an article by a deputy chief physician of the Second Affiliated Hospital of Heilongjiang University of Traditional Chinese Medicine "Drinking too much coffee affects libido and erection." Is drinking coffee beneficial or harmful to sexual performance? The answer is actually very simple, and you don’t even need to ask questions at all. You will know if you try it yourself.

　　 3. Coffee has a definite role in improving exercise capacity, and caffeine has a strong effect, which can improve endurance and athletic performance. This is precisely why caffeine is a stimulant specifically banned by the International Olympic Committee (IOC). The International Olympic Committee (IOC) stipulates that when the concentration of caffeine in urine is greater than 12 μg/ml, it is considered illegal (ie, "positive drug test"). Drinking coffee before exercise can help improve exercise capacity.

　　The long-term effect of drinking coffee (that is, drinking coffee for a long time) is more complicated and needs to be confirmed through scientific research. Unfortunately, although there are many studies on coffee, it is often difficult to reach a consistent conclusion. For many problems, we can only make a rough judgment.

　　 1. Coffee (same as tea) interferes 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 also try not to get mixed with food when drinking coffee.

　　 2. Caffeine has a weight-loss effect, but drinking coffee, especially instant coffee, may not be able to lose weight. Caffeine has a stimulating effect, can increase basal metabolism, reduce sleep time, generally increase heat energy consumption, and help to lose weight. However, if you drink a lot of instant coffee or drink coffee, if you add a lot of sugar, milk or coffee mates, which contain more heat, the weight loss effect will be greatly reduced.

　　3. Mother drinking coffee will have an adverse effect on the fetus and breast-feeding infants. The US Food and Drug Administration (FDA) has issued a statement recommending that women who are or may be pregnant reduce caffeine intake. The Drug Committee of the American Academy of Pediatrics recommends that mothers should not consume more than 300 mg of caffeine per day.

　　 4. Coffee is not good for patients with gastric ulcer. Because coffee can promote gastric juice secretion and increase gastric acid, patients with gastric ulcers should pay more attention when drinking coffee, do not overdose, and do not drink coffee on an empty stomach.

　　 5. Coffee will cause calcium loss. Although there is no direct evidence that caffeine causes osteoporosis, some studies have pointed out that caffeine increases the calcium excreted in the urine, thereby increasing the risk of osteoporosis. Therefore, women who drink coffee regularly should pay attention to calcium supplementation. In addition, there are reports that increased calcium excreted in the urine will increase the risk of kidney stones ("Health News" October 28, 2004).

　　 6. Coffee has anti-cancer effect. There are many reports on coffee and cancer, and most reports support coffee''s role in preventing cancer. For example, in a report published in the American Journal of Gastroenterology by Dr. Larsson and Dr. Volck of the Karolinska Institutet in Sweden, drinking coffee is inversely proportional to the risk of liver cancer. Coffee contains a lot of antioxidants such as green Original acid can fight oxidative stress and prevent the formation of carcinogens. In addition, experiments conducted on animals also clearly showed that coffee and chlorogenic acid have the effect of inhibiting liver cancer (China Economic Net on September 24, 2007). Of course, there are some reports showing that drinking coffee will increase the risk of pancreatic cancer and ovarian cysts (May 20, 2005 "Health News").

　　 7. The effect of coffee on heart disease is not yet clear. Some studies say that a person who drinks 5 cups or more of coffee per day has a two-fold higher risk of heart disease than those who do not drink it. Studies have also said that women who drink more than 5 cups of coffee per week have a 32% lower risk of heart disease than women who do not drink coffee or drink less than 4 cups of coffee per week. Other studies say that there is no connection between coffee and heart disease. It is not known whether these studies considered the intake of trans fatty acids in instant coffee or coffee mates. The harm of too much trans fatty acids to the heart is recognized.

　　 8. Drinking coffee helps prevent gout. According to Xinhuanet''s report on May 28, 2007, researchers in the United States and Canada have found through large-scale investigations that drinking coffee helps reduce uric acid levels in the human blood and achieve the effect of preventing gout (however, this effect does not seem to be related to caffeine ).

　　Summary: The benefits of coffee itself are refreshing, improving exercise capacity (these two functions are very clear), anti-cancer, weight loss, gout prevention, etc. (these effects are not clear enough); the disadvantages of coffee itself are , Interfering with mineral absorption, harmful to the fetus (these two effects are more clear), osteoporosis, kidney stones, adverse to gastric ulcers, etc. (these effects are not clear enough). As for the effect of coffee on cardiovascular and cerebrovascular diseases, the controversy is still very large, and it is difficult to form a tentative conclusion.

　　Trans fatty acids and complex food additives in instant coffee and coffee mates can cause adverse health effects or leave hidden dangers.

　　 Therefore, if you drink coffee, it is advisable to drink 1, 2 cups a day, not too much. Be highly alert for trans fatty acids and food additives in instant coffee or coffee mates.