Economic Observation Network According to the CCTV News app, coffee has gradually become a popular beverage for modern people and a daily essential "life-saving tool" for many office workers.

At present, many studies mention that regular coffee drinking is beneficial to health, such as refreshing, relieving fatigue, preventing type 2 diabetes, and preventing some cancers. A study by a research team from Soochow University shows that drinking coffee can actually offset the harm caused by prolonged sitting - those who sit for ≥ 6 hours a day and do not drink coffee have a 1.58 times higher risk of death than those who sit for<6 hours a day and drink coffee; Among people who do not drink coffee, the longer they sit, the higher their risk of all-cause mortality.

However, coffee is not suitable for everyone,There are 8 types of people who cannot blindly drink coffeeBe sure to pay special attention.

Coffee contains a high amount of caffeine, which has a certain refreshing effect. Caffeine has a similar structure to adenosine, a metabolite of the body's energy supply substance adenosine triphosphate (ATP), and can compete to bind to receptors that cause fatigue and sleep signals, exerting biological activity to promote wakefulness and improve fatigue.

Because of this, many office workers rely on coffee to stay alert and work hard.

Studies have shown that caffeine is rapidly absorbed by the human body, typically reaching its peak within 15 minutes to 2 hours after consumption, spreading throughout the body, and crossing the blood-brain barrier. The half-life in the adult body is generally 2.5-4.5 hours. So, in general, drinking coffee 5 hours before planning to sleep will not have a significant impact on a normal person's sleep. For example, if you go to bed at 22:00, then drink coffee before 5pm.

However, different groups of people have varying levels of tolerance to caffeine. For those who already have poor sleep, insomnia, or sleep disorders, it is still advisable to drink less or avoid coffee as much as possible.

Although an increase in heart rate after drinking coffee is a normal phenomenon, it still needs to be taken seriously, especially for people who already have arrhythmia.

Arrhythmia is mainly caused by abnormal electrical conduction of the heart, resulting in irregular, too fast or too slow heartbeat. More than 80% of American doctors recommend patients with palpitations or arrhythmias to quit or reduce their intake of caffeine.

In addition, some studies have shown that for most people, even those with arrhythmia or those at high risk of arrhythmia, although there is no clear threshold for caffeine harm, a daily intake of less than 400 milligrams of caffeine seems safe and may even have a protective effect on arrhythmia;However, for individuals with malignant arrhythmias and high-risk individuals with caffeine sensitive arrhythmias, it is still advisable to avoid caffeine intake as much as possible.

400 milligrams of caffeine is equivalent to no more than 4 cups of pure coffee (150 milliliters per cup). If it is purchased coffee, the number of cups can be calculated by comparing the caffeine content per cup on the packaging label; If it is a small packet of 1.8-2g instant coffee, generally no more than 5 bags per day.

Coffee can stimulate the gastrointestinal tract and increase the secretion of stomach acid.

For people with normal stomach function, this will not affect their health.But for people who already have stomach problems, such as gastric ulcers, excessive gastric acid secretion, and gastroesophageal reflux disease, frequent or excessive consumption of coffee may lead to symptoms such as nausea, vomiting, acid reflux, and heartburn.

Irritable bowel syndrome is a common functional bowel disease, and patients may experience frequent diarrhea and constipation.

Caffeine can stimulate the secretion of gastric acid and cholecystokinin in the digestive system, thereby promoting colon motility and causing symptoms such as diarrhea.In general, patients with irritable bowel syndrome are more sensitive to caffeine, and drinking it may increase symptoms of gastrointestinal discomfort and diarrhea.Reducing caffeine intake can lower the incidence of symptoms related to irritable bowel syndrome.

The caffeine, tannic acid and other components in coffee can indeed affect calcium absorption, and caffeine diuresis can increase calcium loss, but this has little effect on healthy people.A study suggests that caffeine has minimal negative effects on calcium absorption, and only 1-2 tablespoons of milk can completely counteract it.

Based on a large amount of population data, food safety regulatory agencies such as the European Food Safety Agency, the US Food and Drug Administration, Health Canada, and the Australian and New Zealand Food Standards Agency believe that a daily intake of caffeine within 400 milligrams for healthy adults will not have adverse effects on cardiovascular function, behavior, reproduction and development, bone health, and there is no risk of acute poisoning. So, healthy people don't have to worry about drinking coffee causing osteoporosis.

However, for individuals who already suffer from osteoporosis, the "Chinese Expert Consensus on the Diagnosis, Treatment, and Management of Osteoporotic Pain in the Elderly (2024 Edition)" recommends avoiding excessive consumption of coffee.

Studies have shown that caffeine in coffee can cause abnormal increase in intraocular pressure in glaucoma patients, which is a risk factor for the development of glaucoma. Elevated intraocular pressure can cause damage to the optic nerve and visual function, and in severe cases, can lead to blindness.

Therefore, glaucoma patients should avoid drinking high caffeine beverages such as coffee in their daily lives to prevent further damage to the eyes caused by increased and fluctuating intraocular pressure.

The currently recommended safe intake of caffeine for children and adolescents internationally is no more than 2.5-3 milligrams per kilogram of body weight. That is to say, for children and adolescents weighing 40 kilograms, the intake of caffeine is 100-120 milligrams, which is about one cup of coffee. Of course, it's better not to drink.

This is because children who are in the growth and development stage have weaker ability to metabolize caffeine than adults, which not only affects sleep but also physical development.

The "Chinese Children and Adolescents Snack Guide (2018)" also mentions that foods containing caffeine can have negative effects on children's brain development and function.Therefore, children aged 12 and under are prohibited from consuming caffeine and do not drink caffeinated beverages such as strong tea and coffee.

According to the Scientific Consensus on Coffee and Health, it is not recommended for pregnant women to drink coffee, and if consumed, no more than 2 cups per day. Although institutions such as Health Canada, the American College of Obstetricians and Gynecologists, and the American Maternity Association believe that coffee consumption during pregnancy should be moderate (no more than 150-300mg of caffeine per day, about 2 cups), pregnant women should not be encouraged to drink coffee.

Therefore, for women who do not have the habit of drinking coffee regularly, it is recommended not to drink coffee during pregnancy and lactation; For women who have a habit of drinking coffee regularly, it is best to limit their coffee consumption.

Summary

Although drinking coffee is beneficial for health, it should also be limited. The scientific consensus on coffee and health suggests:The daily intake of caffeine for ordinary adults should be controlled within 400 milligrams.

Different groups of people have varying levels of tolerance to caffeine. It is recommended that the 8 groups of people mentioned in the article, as well as those who are sensitive to caffeine, limit or avoid caffeine intake according to their own circumstances.