Do not drink too much coffee can speed up the aging process of the brain.

About 85% of Americans admit to drinking coffee every day. Coffee temporarily increases your heart rate and blood pressure, making you feel refreshed and focused. However, Dr. Teresa Aubrey, a neuroscience expert at Florida State University, believes that drinking too much coffee can make people jittery and nervous, dehydrating brain tissue and reducing blood supply, which can accelerate the aging process of the brain.

You may think that coffee can refresh your mind, make you smarter, and make you much more productive. Is that really the case? The study found that the caffeine in coffee can only improve the efficiency of jobs that do not require fine thinking or abstract thinking. Caffeine seems to speed up your thinking a little bit and enhance your ability to remember mechanically, but it doesn't enhance your creative thinking. Moreover, the body will gradually tolerate caffeine, and you have to consume more and more caffeine to have the same refreshing effect.

Drinking five cups of coffee may increase the risk of hearing voices, according to an Australian study. A 2009 study found that people who drank three cups of coffee were three times more likely to hear or see hallucinations. Please note that caffeine is found not only in coffee beans, but also in tea, cocoa beans and processed products derived from these ingredients, but also in a variety of drugs, such as painkillers, diuretics, vitamin supplements, etc. Some studies have found that caffeine can increase the level of hydrocortisone in your body, making you feel more nervous. Consuming large amounts of caffeine can also irritate your gastrointestinal tract, cause headaches, cause anxiety, and make you diuretic, preventing you from getting a good night's sleep.

Pharmacologically, Aubrey recommends consuming no more than 417 milligrams of caffeine a day. Some doctors have found that consuming 600 milligrams of caffeine a day can cause anxiety, dyspnea and even arrhythmias-about the same amount as drinking a liter of freshly ground coffee beans. Caffeine begins to feel after being ingested into the body for 10 or 15 minutes, and the effect lasts for 2 to 3 hours. People who are used to consuming 300 milligrams of caffeine a day will experience withdrawal symptoms after abruptly stopping their intake, including fatigue, depression, irritability, tremors and headaches.