When summer comes, people drink tea and coffee more and more frequently. Although the two drinks have different tastes, they can both induce diuresis and reduce swelling. It turns out that they all contain caffeine, which can eliminate more sodium intake in our body. Tea and coffee promote sodium excretion, diuresis and detumescence. If you eat a high-salt diet for a long time and consume too much sodium, which exceeds the upper limit of renal excretion, the sodium reabsorbed into the blood by renal tubules will also increase. When the sodium in blood vessels increases, it will lock more water, which will lead to an increase in blood volume and increase the burden on the heart. High sodium can also lead to poor vasoconstriction and dilation, harden blood vessels and increase the risk of coronary heart disease. Both tea and coffee contain an alkaloid called caffeine, which can inhibit the reabsorption of sodium by renal tubules, resulting in the decrease of sodium re-entering the blood, and the excess sodium is dissolved in water, forming urine to be excreted. Caffeine helps the body excrete more sodium through this form, which is why it is often said that drinking tea and coffee can induce diuresis and reduce swelling. Patients with coronary heart disease had better not drink coffee. Drinking too much coffee will excite the sympathetic nerve and accelerate the heartbeat, which is not good for cardiovascular system. People with tachycardia and poor sleep should not drink coffee. If people who have symptoms such as rapid pulse, rapid heartbeat or trembling tinnitus after drinking a lot of espresso continuously, they should try to avoid drinking coffee and be alert to heart disease. Coffee is bitter. Many people drink coffee with coffee partners, milk and sugar. If they drink a lot for a long time, their calories will increase. In addition, coffee can promote the digestion and absorption of food, easily make people obese and increase the risk of coronary heart disease. Friends with coronary heart disease, you should drink coffee in moderation: drinking coffee in moderation can refresh you. If consumed in large quantities, it may cause gastritis, gastric ulcer, insomnia, arrhythmia and even myocardial infarction. Normal adults are advised to drink no more than 3 cups of coffee a day (200ml per cup), and friends with coronary heart disease should not drink more than 1 cup. Less sugar: Coffee is bitter, so many people add sugar and milk. But both sugar and milk will increase calories and make people obese. Try to choose pure coffee (instant coffee contains many other sugar additives). If pure coffee is too bitter, you can choose to add less coffee powder and more water. Pay attention to time: coffee should be drunk after meals, not on an empty stomach or before going to bed. Don't drink with wine: drinking coffee and wine together will make you drunk easily on the one hand and strengthen your heart on the other, so cardiovascular patients must pay attention to it. Drinking green tea is not friendly to the heart but more beneficial to the heart than coffee. Drinking too much can easily cause heart discomfort. Compared with white tea and black tea, green tea contains at least four kinds of tea polyphenols active substances (catechins), which have the following benefits for cardiovascular system: preventing arteriosclerosis: catechins can prevent platelet aggregation and reduce blood viscosity; Catechin can resist oxidation, remove excess oxygen free radicals in the body and protect vascular endothelial cells; Promote the synthesis of vasodilator NO and inhibit vasospasm. So drinking more green tea can better prevent atherosclerosis. Lowering blood pressure: Catechin can inhibit angiotensin I converting enzyme and prevent angiotensin I from converting into angiotensin II with strong vasoconstrictive effect, so it can lower blood pressure. Flavonoids in green tea can also maintain vascular elasticity and prevent vasospasm. People with hypertension drink more green tea, which helps to lower blood pressure. Reduce bad cholesterol in blood: catechin can inhibit the absorption of cholesterol in food by intestine, promote the excretion of excess cholesterol in the body and slow down the formation of atherosclerosis; Improve the content of beneficial cholesterol (high density lipoprotein) in blood and promote the protection of cardiovascular system. Therefore, drinking more green tea can help us clear bad cholesterol from blood vessels and keep good cholesterol. Although green tea is good, we should avoid the following pits: drinking tea on an empty stomach is prone to acid reflux, belching and abdominal distension, because drinking tea on an empty stomach will dilute gastric acid and reduce digestive function. Do not drink strong tea: drinking too strong tea (especially on an empty stomach) can easily cause palpitation, rapid heartbeat, dizziness, fatigue and other discomfort, because the caffeine content in strong tea is too high and it is absorbed too quickly on an empty stomach. It is not suitable to substitute tea for medicine: the acid in tea can combine with many drugs to produce precipitation, which hinders absorption and affects the efficacy. It is not advisable to drink tea before going to bed: drinking tea before going to bed can easily lead to insomnia, and the number of going to the toilet in the middle of the night increases, which affects the quality of sleep, because caffeine and theophylline in tea have exciting and refreshing effects. Summer is coming, let's drink less coffee and more green tea, so that our hearts can spend the hot summer. References: Wu, Fan Fangyuan, et al. Physiological function and mechanism of caffeine. [J]。 Tea science. 20 10.4(32):235-242 2, Fang, et al. Research progress on health care function of coffee. [J]。 China Journal of Food Hygiene. Relationship between green tea and coronary heart disease. 1000000006 1[D] Nanjing Medical University. 20 10 4 ding jingzhen, Zhang Wei. Research progress on cardiovascular protection mechanism of green tea components. Journal of pharmacoepidemiology. 2006, 15 (6): 340-342 statement: The above content comes from the Internet, and the copyright belongs to the original author. Please inform me if your original copyright is infringed.