Some people say they experience "hand tremors" after drinking coffee, some say they "break out in cold sweats," and some claim that coffee causes cancer.

Why do these reactions occur when drinking coffee? Recently, rumors were circulating online about coffee causing cancer. Is this true?

In the latest issue of the New England Journal of Medicine (NEJM), a collaborative study between Harvard Medical School and the National University of Singapore delved into the physiology, metabolism, and toxic effects of coffee, as well as its associations with various chronic diseases.

Based on substantial evidence, consuming coffee does not increase the risk of cancer or cardiovascular diseases. In fact, moderate daily coffee consumption has been shown to reduce the risk of several chronic diseases.

However, some individuals experience accelerated heart rate after consuming coffee. Does coffee have any effect on cardiovascular and other chronic diseases?

1. Cardiovascular Diseases:

Evidence suggests that, at the population level, coffee does not increase the risk of cardiovascular diseases. While caffeine can temporarily elevate blood pressure, the body can develop tolerance to this within a week, and clinical trials have not found substantial effects of coffee on blood pressure.

Regarding blood lipids, although coffee polyphenols can raise cholesterol levels, this is mainly influenced by different preparation methods.

Randomized trials have shown that compared to filtered coffee, consuming an average of six cups of unfiltered coffee per day increases the risk of elevated LDL cholesterol and major cardiovascular events by 11%. Drinking less unfiltered coffee can help control blood lipids.

2. Liver Diseases, Stones, and Parkinson's:

Caffeine helps prevent liver cirrhosis and fibrosis, while coffee polyphenols can prevent liver fibrosis and hepatic steatosis. Studies also indicate a reduced risk of kidney and gallstones with coffee intake.

Research conducted in the US, Asia, and Europe shows a significant inverse association between caffeine intake and the risk of Parkinson's disease, consistent with animal experiments.

3. Obesity and Type 2 Diabetes:

Caffeine improves energy balance and is beneficial for weight management. In metabolic studies, it was found that consuming caffeine multiple times during the day activates "brown fat," increasing 24-hour energy expenditure by 5%. Moderate caffeine intake is also associated with a reduced risk of type 2 diabetes.

It's surprising that drinking coffee not only doesn't cause cancer but also has so many health benefits. However, this doesn't mean that the more you drink, the healthier you'll be. The key to health is understanding how much is right for you.

Individual sensitivity to caffeine varies, as does the rate at which caffeine is metabolized, resulting in differing levels of tolerance. In certain situations, individuals may be more sensitive to the effects of caffeine.

Moderate coffee consumption is beneficial for the body, but excessive intake can lead to symptoms such as insomnia, anxiety, tremors, stomach discomfort, increased heart rate, headaches, nausea, and restlessness. Experiencing these symptoms after consuming caffeinated beverages indicates overconsumption.

So, what is the appropriate amount to drink?

For healthy adults, it is recommended not to exceed 400 milligrams per day, equivalent to 2-3 cups of regular American-style coffee.

If someone regularly drinks coffee every day and suddenly stops, they may experience anxiety, headaches, lack of concentration, irritability, and fatigue. This can give the impression of being addicted to coffee.

In reality, this is a manifestation of caffeine withdrawal syndrome, which is particularly common among individuals experiencing high work-related stress. Generally, consuming around 100 milligrams of coffee per day is less likely to lead to addiction.

In summary, recent research affirms that moderate coffee consumption offers numerous health benefits without increasing the risk of cancer or cardiovascular diseases. However, individual sensitivity to caffeine varies, and excessive intake can lead to adverse effects. Therefore, enjoying coffee in moderation is key to reaping its potential health advantages while minimizing risks.