Coffee "prescription": three cups of hand-brewed coffee and one cup of latte every day

Take three cups of brewed coffee and one cup of latte every day, on time and follow the doctor's advice.

Nahla: The author of this issue is Dr.S, who we are going to introduce to you! Dr.S is the handsome guy in white who made coffee for us at the offline market of Walking Coffee Map a few days ago. He is a postdoctoral fellow in the Department of Cardiology of Peking University Medical School. He couldn't stand the coffee medical science popularization posts copied and pasted from Baidu and Google on the Internet, so he promised us to write real science! If you have any questions about coffee and health, you can leave a message, and Dr.S will give you a real scientific and professional answer.

Finally, the "third wave of coffee" has flowed into China from the other side of the Pacific Ocean (such as coffee concepts in Australia and the United States, and specialty coffee beans in America). Coffee lovers can now distinguish between cappuccino, latte, and espresso, and those with a stronger thirst for knowledge know what the unfamiliar terms flat white and piccolo mean. More and more people are beginning to like black coffee/drip coffee that is "sour and bitter" and has a bit of "isatis root" flavor.

After satisfying their taste buds, many coffee addicts begin to worry about the effects of drinking coffee on their health:

"Eh? If I keep drinking coffee like this every day, I'm going to die sooner or later?!"

Let me tell you first: Don’t worry, it will definitely happen!

When we discuss the impact of something on health, it must be within the limit. After all, breathing too much oxygen can kill people.

So is coffee good or bad for your health?

Before answering this question, let's first talk about the biologically active substances in coffee.

At present, we have discovered nearly a thousand biologically active substances in coffee, and the three most important types of substances are: caffeine, diterpenoids and chlorogenic acid.

Among them, the first thing that comes to mind when we mention coffee is probably caffeine . Its main function is to excite the central nervous system , which is also the main substance of coffee's refreshing effect; in addition to refreshing, caffeine can also excite the respiratory system and muscle system (including cardiac muscle and skeletal muscle), thereby improving athletic performance .

Therefore, we can see that the reason why coffee was used in religious activities (the euphoric effect significantly improves people's imagination and visual sensitivity ) and in wars (from ancient warriors drinking coffee before battles in the Arab region to the German army using coffee beans as important military supplies during World War II) was mainly due to the use of caffeine.

The diterpenoids in coffee mainly include cafestol and coffee bean resin .

The fats that give us a strong sense of satisfaction in espresso come from them. Without discussing its various biological effects, what we can remember is that these substances may increase cholesterol (especially low-density lipoprotein cholesterol, a "bad" cholesterol).

The third major component of coffee is chlorogenic acid , which is a potent antioxidant . Excessive "oxidation" (a non-technical term) is an important mechanism that causes us to suffer from various diseases. The benefits of coffee we will discuss next are largely due to it.

At this point, we already know that in addition to caffeine, coffee has many other important components that cannot be ignored. Drinking a cup of coffee means that you will inevitably receive the influence of several substances at the same time.

Discussing the effects of each substance in isolation means there is a possibility of misleading ourselves, so we plan to start with existing medical research to discuss the "comprehensive effects" of coffee on health.

Today, let’s start with the health of the cardiovascular system.

1

Does drinking coffee cause high blood pressure?

Due to the effect of caffeine, the direct effect of drinking coffee is to increase blood pressure, and the substance that exerts the effect of increasing blood pressure is mainly caffeine. However, after drinking coffee regularly, the sensitivity of blood pressure changes to coffee will decrease. Studies have shown that long-term drinking of coffee does not increase the incidence of hypertension, which is the effect of antioxidants such as chlorogenic acid.

2

Can drinking coffee prevent diabetes?

Studies have shown that people who drink more than 6 cups of coffee a day have a lower risk of developing type 2 diabetes than those who drink less than 2 cups of coffee. A study involving 88,000 female subjects aged 26 to 46 showed that drinking coffee can significantly reduce the incidence of type 2 diabetes, and this benefit can be achieved regardless of whether it is regular coffee or decaffeinated coffee; and whether coffee contains caffeine or not, the more you drink, the better it is for type 2 diabetes. And the antioxidant chlorogenic acid plays a role in this process.

3

Coffee and high blood lipids?

As mentioned before, diterpenoids, an important component of coffee, can increase the "bad" cholesterol in the blood. Therefore, in this sense, coffee is not good for the body. However, different production methods also have different degrees of retention of diterpenoids. The longer the coffee powder is in contact with water, the more diterpenoids are precipitated, and the more unfavorable it is for the cholesterol level in the body.

✖Therefore , brewed coffee made with an American coffee machine (the method used by major fast food restaurants such as McDonald's) contains more of these substances, and this type of coffee may increase blood cholesterol;

✔ As for drip coffee/hand-brewed coffee, in addition to the relatively shorter hand-brew time, because of the filter paper filtration step, most diterpenes cannot pass through the filter paper into the coffee liquid (people with experience in coffee making should know that the reason why some Japanese hand-brewed methods that use flannel are mellower than the filter paper filtration method is, to a certain extent, because diterpenes can easily pass through the gauze into the coffee liquid). Therefore, its diterpenes are relatively less and the negative impact on blood lipids is relatively small.

A study involving 132,000 subjects showed that long-term consumption of drip coffee had no significant effect on serum cholesterol levels.

4

Coffee and Coronary Heart Disease?

First, let me explain to you what coronary heart disease is. Coronary heart disease is caused by various reasons, which cause the arteries that supply blood to the heart (causing the direction of the artery to be called the coronary artery) to become narrow, resulting in insufficient blood supply to the heart. If the narrowing occurs suddenly, it will cause myocardial infarction.

Hypertension, diabetes and hypercholesterolemia can all increase the risk of coronary heart disease (but none of them are more harmful to the heart than smoking, and by the way, let me remind you that smoking is harmful to health). The previous chapter has already pointed out that drinking coffee in a "reasonable" way can prevent diabetes without having a negative impact on blood pressure and blood lipids.

Similar studies also suggest that moderate (>2 cups/day) or more coffee consumption can reduce the incidence of coronary heart disease.

Regarding coffee and coronary heart disease, another issue is worth paying attention to:

Can patients who have been diagnosed with coronary heart disease, or even severe coronary heart disease (such as myocardial infarction) still drink coffee?

The answer is yes!

Medical practitioners have raised this question because the direct effect of caffeine is to stimulate "nerve excitement", and a part of the nervous system called the sympathetic nerves can also be stimulated by caffeine, which is more dangerous for patients with coronary heart disease; at the same time, arrhythmias such as "premature beats" that do not endanger healthy people are also a potential risk factor for deterioration in patients with coronary heart disease, which may also be stimulated by caffeine.

Subsequent studies have largely dispelled people's excessive concerns about this: a study followed up 106 patients with myocardial infarction and found that coffee did not increase the incidence of arrhythmias, and had no significant correlation with whether the condition of myocardial infarction patients worsened or even died. This can be regarded as whitewashing coffee to some extent!

Furthermore, further studies have found that coffee can stimulate the parasympathetic nerves, which to a certain extent antagonize the sympathetic nerves, for patients who have suffered myocardial infarction (the parasympathetic nerves can produce effects such as slowing the heart rate), and therefore can even have certain beneficial effects on patients with myocardial infarction. At the same time, coffee also reduces a substance that can lead to a poor long-term prognosis for patients with myocardial infarction (a substance called C-reactive protein), and thus may produce long-term benefits.

"I am DR.S. A small explanation of my rigorous academic approach"

1 ounce = 30 ml. Most of the studies mentioned in the article refer to 8 ounces per cup. A cup of coffee of about 200 ml contains about 95-200 mg of caffeine. Some studies distinguish different sources or production methods of coffee (including instant coffee), while others do not. However, from the above-mentioned article, when discussing the effects of coffee, when we usually calculate how many cups of coffee we drink every day, using hand-brewed black coffee as the standard, the degree of consistency with the research results will not be lower.

The main contents of this article refer to the following literature:

O'Keefe JH et, al. Effects of habitual coffee consumption on cardiometabolic disease, cardiovascular health, and all-cause mortality. J Am Coll Cardiol. 2013 Sep 17;62(12):1043-51.

The "prescription" for healthy coffee drinking: three cups of hand-brewed coffee and one cup of latte (Part 1) is about the origin of the "prescription". You will have to wait for the next issue to talk about diseases that will be caused by drinking more than four cups or less than four cups, and also the harm of excessive coffee intake and how to avoid it.

The article is not finished yet, it will be continued in the next issue!

SO Who is Dr.S?

Dr. S (Sugar and Sunshine Sina Weibo @Sugarman), Pisces, a beautiful boy from Tianjin, a postdoctoral fellow in the Department of Cardiology at Peking University. He loves making latte art, drinking hand-brewed coffee, and is a moderate coffee addict. He also loves football, reading, music, and art. He claims that his favorite painter is Caravaggio. He wears the title of doctor, but his main job for half of his life is taking exams. He is an idealist with no money. His favorite living person is Woody Allen, and his favorite eternal person is Su Shi.