1. Iron agent should not be taken with tea, milk and coffee. Because milk contains high phosphorus, it will affect the absorption of iron. Tannic acid in tea and coffee can reduce iron absorption by 75%. It is advisable to take warm boiled water.

2. Tannic acid in tea and coffee will reduce the absorption of calcium. Therefore, it is best to drink tea and coffee between meals.

3. Caffeine-containing drinks and foods can cause nausea, vomiting, headache, and rapid heartbeat after being drunk in large quantities by pregnant women. Caffeine can also enter the fetus through the placenta, affecting fetal development.

Many doctors believe that drinking 1~2 cups (6~8 ounces each) of coffee, tea or carbonated drinks every day will not affect the fetus. But for the sake of caution, it is best for pregnant women to ban it. Caffeine can lead to an increase in abortion rate, so drink decaffeinated drinks.

People who want to lose weight should not drink more coffee. The average coffee partner contains more milk, sugar and fat. Coffee itself may stimulate the secretion of gastric juice, improve food digestion and absorption, not only can not lose weight, but also make people fat.

6. Children should not drink coffee. Caffeine can excite children's central nervous system, interfere with children's memory and cause ADHD.

7. Strong tea, coffee and carbonated drinks are also risk factors for the formation of digestive tract ulcers.

8. Supplementing caffeine when you are nervous can improve your alertness, sensitivity, memory and attention. But if you drink more coffee than you are used to, you will have the same dose of stimulants, which will cause tension. For people with anxiety tendency, caffeine can aggravate the symptoms of sweating, palpitation and tinnitus.

9. Caffeine for strengthening hypertension is often combined with other simple painkillers because of its analgesic effect. However, if you take a lot of caffeine for a long time, if you already have high blood pressure, using a lot of caffeine will only make your situation worse. Because caffeine alone can raise blood pressure, if combined with emotional tension, it will have a dangerous multiplier effect. Therefore, people at risk of hypertension should especially avoid drinking caffeinated drinks when working pressure is high. Some people who drink coffee all the year round think they are immune to the effects 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.

10. Caffeine itself 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 adversely affect the preservation of bone mass and may increase the threat of osteoporosis in women. However, the premise is that people who usually have insufficient calcium intake in food, or people who don't exercise often, and postmenopausal women, due to insufficient estrogen, calcium loss, coupled with a large amount of caffeine, may pose a threat to bones. If you can enjoy it in a reasonable amount, you can still do it without choking.

The benefits of drinking coffee

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.