As you all know, caffeine contained in coffee or refreshment drinks can have the effect of reviving your mind and eliminating sleepiness. However, there are so many kinds of coffee, what is the best effect? And how did they get rid of it?
01, why can coffee eliminate the feeling of difficulty?
Caffeine eliminates difficulty because it blocks an inhibitory neurotransmitter called adenosine, and caffeine reduces their effects. Adenosine's original role is to promote sleep, reduce the pulse speed of the heart, cause pain, promote blood circulation, reduce renal blood flow velocity, and so on.
Because caffeine blocks adenosine's "sleep-promoting effect," it has an exciting, refreshing effect. In other words, the principle of "caffeine refreshment" is that caffeine artificially blocks natural sleepiness, which deceives the brain so that it does not notice the natural sleepiness.
In our daily life, drinking only two or three cups of coffee does not have much effect. However, if you continue to consume too much caffeine, it can cause the brain to be disturbed by the rhythm of waking and sleeping.
Natural sleepiness is no longer due to natural time, which eventually leads to insomnia or even insomnia.
02. hot coffee is faster and more refreshing
In fact, hot coffee is a faster way to wake up. The low temperature of iced coffee causes small intestinal mucosa and capillaries to contract, delaying the body's absorption of caffeine, so that it cannot be quickly refreshed.
At the same time, the caffeine concentration in the blood of iced coffee also rises at a slower rate than hot coffee for a while, and it would be better to drink hot coffee if you want caffeine to work as soon as possible.
03,9,12,15
The best coffee time of the day is 9: 00 a. M., 12:00 and 3: 00 p.m. After drinking coffee, caffeine begins to work, and caffeine concentrations in the blood are about half of the maximum over a period of two and a half hours to four and a half hours.
For older people, the time is about four to five hours, in other words, caffeine is less effective. Therefore, a reasonable time to drink coffee can maximize the effectiveness of caffeine.
Instead of constantly drinking coffee to wake yourself up, it's better to wait until caffeine's "blood concentration" is reduced to half or less, which is the most efficient way to get caffeine. So drinking coffee at 9: 00 a. M., 12: 00 a. M. and 3: 00 p. M., not only makes good use of caffeine, but also ensures that it doesn't affect sleep.
Why does coffee cause frequent urination?
It is true that urine is made by the kidneys. One of the effects of adenosine, mentioned earlier, is the "effect of lowering the velocity of blood flow in the kidney," which is inhibited by caffeine intake, and the amount of blood flowing toward the kidney increases, and the blood continues to flow toward the kidney. The kidneys continue to produce new urine that causes frequent urination.
Excessive intake of caffeine not only discourages sleepiness, but also increases the number of times you get up and go to the toilet. So it reduces the quality of sleep, so try to avoid coffee and caffeine drinks in the evenings and evenings, and besides that, what are the benefits of drinking coffee?
Here, make a small summary, if you need, may as well have a cup of coffee.
Reduce the risk of liver cance
"according to the amount of coffee consumed," said a researcher at the Mario Negri Institute of Pharmacology, University of Milan, in the journal Clinical Gastroenterology and Hepatology. Any type of coffee can reduce the risk of hepatocellular carcinoma (HCC) by 50%. "
The report, which looked at 16 studies and 3153 cases from 1996 to 2012, showed that the positive effect of coffee in preventing liver cancer is due to the well-known preventive effect of coffee on diabetes. Diabetes is one of the main causes of liver cancer.
Another explanation is that coffee can effectively prevent liver cirrhosis and play a beneficial role in liver enzymes, thus preventing liver cancer.
Reducing the risk of colorectal cance
Coffee reduces the risk of colorectal cancer by 26 percent, according to a recent study reported by the Norris Comprehensive Cancer Center at the University of Southern California. This is a population-based, molecular epidemiological study of colorectal cancer in northern Israel, in which 5145 patients with colorectal cancer and 4097 healthy people without a history of colorectal cancer were enrolled. The final data from the semi-quantitative coffee intake frequency questionnaire showed that the risk of colorectal cancer was reduced by 26 percent after a moderate daily intake of coffee (1 to 2 servings per day). At the same time, as coffee consumption increases, the risk of colon cancer decreases. Moreover, the trend was evident in both colon and rectal cancer.
It is more gratifying to note that, in addition to the caffeine, other ingredients in the coffee play a good role.
"Coffee contains a variety of ingredients that promote colorectal health, caffeine and polyphenols have antioxidant effects, nigrins promote colon peristalsis, and diterpenoids resist oxidative stress damage," the researchers said.
Reduce the recurrence rate of colon cance
Coffee has another effect on colon cancer. Researchers at the Dana Faber Cancer Institute have published a study in the Journal of Clinical Oncology
"frequent coffee consumption significantly reduces tumor recurrence and increases survival in stage 3 patients with colon cancer. And among them, caffeine plays a vital role. "
The news is a rare piece of good news for many colon cancer patients. The researchers followed up 953 patients undergoing chemotherapy
Following their six-month diet, they found that "patients who drank four or more cups of coffee a day (about 460 milligrams of caffeine) were 42 percent less likely to have cancer recurrence than those who did not." During follow-up, patients who did not drink coffee were 33 percent more likely to die from cancer or other causes than those who drank four or more regular cups. "
Reduce the risk of melanoma, skin cance
Coffee has become more and more common, and coffee has become a killer against skin cancer.
In 2015, a study by the National Cancer Institute found that drinking more than four cups of coffee a day could reduce the risk of skin cancer by 20 percent over a decade.
The study looked at four hundred and forty seven thousand participants, aged 50 to 71, who were asked to use a food questionnaire.
There was no cancer at the beginning of the study, and over the course of more than a decade of research, more than 2900 subjects developed malignant melanoma and more than 1900 suffered from melanoma in situ.
Excluding factors such as age, diet, and family history and considering only the relationship between caffeine and melanoma, more than four cups of coffee a day can reduce the risk of skin cancer by 20 percent over a decade. In theory, various ingredients in coffee have been shown to affect a significant number of molecular pathways that reduce the risk of skin cancer associated with ultraviolet light.
Reduce the risk of head and neck cance
A report on the risk of head and neck cancer, a survey conducted by Aichi prefecture Cancer Center in Japan. They found that people who drank more than three cups of coffee a day had a lower risk of head and neck cancer by about 40 percent than those who did not.
Inhibition of breast cancer growth
Breast cancer has become one of the major cancers afflicting women. For women diagnosed with breast cancer and treated with tamoxifen, coffee drinks can inhibit tumor growth and reduce the risk of recurrence, according to a study published in the journal Clinical Cancer Research by Skane University Hospital at the University of Lund.
The study of 1090 breast cancer patients in Sweden focused on the relationship between caffeine and caffeic acid, as well as tumor characteristics, and disease-free survival.
In at least 500 women treated with tamoxifen, women who drank at least two cups of coffee a day had a lower risk of breast cancer recurrence than women who drank less than two cups of coffee or did not drink coffee, with smaller tumors, the study found. The incidence of hormone-dependent tumors was lower. Caffeine and caffeic acid can block cell cycle progression and enhance cell death, enhancing tamoxifen treatment, the study suggests.
Reduce the risk of death
Harvard School of Public Health Professor Hu and colleagues have done a large study, published in the Nov. 16, 2015 Journal of Circulation. The study showed that among non-smokers who drank less than 1 cup of coffee, 1 cup of coffee, 3 cups of coffee and > 5 cups of coffee a day, the overall risk of mortality was reduced by 6%, 8%, 15%, and 12%, respectively.
The decline in mortality is mainly related to cardiovascular death, neurological disease death and suicide mortality.