Recently, a 53-year-old male patient in Can Tho was hospitalized with acute myocardial infarction, with a number of accompanying risk factors such as smoking, dyslipidemia, frequent late-night work, and especially the habit of drinking up to 10 cups of coffee a day.
Experts advise against drinking too much coffee in a day - Illustration photo: HA THANH
According to Dr. Nguyen Huy Hoang (Vietnam Society of Underwater Medicine and Hyperbaric Oxygen Therapy), this is not an isolated case but a warning about the abuse of high doses of coffee, transforming a familiar beverage into a dangerous cardiovascular risk factor.
A "double-edged sword" for the cardiovascular system.
According to Dr. Hoang, coffee can offer many health benefits if consumed in moderation. In healthy individuals, drinking about 2-3 cups a day may help reduce the risk of stroke, mild heart failure, and some cardiovascular events.
However, when exceeding safe limits, especially at 10 cups a day, coffee is no longer simply an "anti-sleepiness agent." The main reason is caffeine, which stimulates the sympathetic nervous system, increasing heart rate, temporarily raising blood pressure, and increasing the oxygen demand of the heart muscle.
In individuals with pre-existing atherosclerosis, these changes can trigger angina or lead to acute myocardial infarction.
Experts recommend that the total safe amount of caffeine should not exceed 400 mg per day for healthy adults and should be reduced to below 200 mg/day for those with cardiovascular disease or hypertension.
The risks of filter coffee and common habits
In Vietnam, many people are accustomed to drinking filter-brewed coffee, which has a high caffeine content, usually 100-150 mg per cup.
"Therefore, drinking 10 cups a day means consuming 1,000-1,500 mg of caffeine, which is many times higher than the safe level," Dr. Hoang estimated.
Furthermore, unfiltered filter coffee contains oily compounds such as cafestol and kahweol (diterpene group). These substances increase bad cholesterol (LDL), contributing to the progression of atherosclerosis.
Therefore, maintaining a habit of drinking this type of coffee in large quantities over a long period can significantly increase blood cholesterol levels, laying the groundwork for cardiovascular events.
In the case of the 53-year-old patient, the risk did not stem from a single factor but rather from the combined effect of several other unhealthy habits.
In particular, smoking 10-12 cigarettes a day causes nicotine to continuously stimulate the sympathetic nervous system, increasing heart rate, blood pressure, and vascular stiffness.
When combined with high doses of caffeine, this effect not only accumulates but is also amplified, increasing pressure on the blood vessel walls and the oxygen demand of the heart muscle.
In addition, working late and drinking coffee throughout the day disrupts the circadian rhythm. Normally, blood pressure decreases at night to allow the cardiovascular system to rest, but caffeine interferes with this process, causing blood pressure to remain high for an extended period.
In addition, caffeine inhibits melatonin—a hormone that regulates sleep and protects cardiovascular health—while maintaining high cortisol levels at night, increasing inflammation and oxidative stress in the body.
Vietnam has many delicious types of coffee, but it should be consumed in moderation to ensure good health.
What mechanisms lead to myocardial infarction?
According to Doctor Hoang, there are two main mechanisms by which high doses of coffee can lead to myocardial infarction.
Firstly, caffeine increases blood pressure and heart rate, putting significant pressure on the blood vessel walls. In already weakened atherosclerotic plaques, this force can cause rupture, triggering blood clot formation and leading to coronary artery blockage.
Secondly, caffeine can cause coronary artery constriction, especially in people who already have narrowed arteries. This constriction can disrupt blood flow to the heart, leading to a heart attack even if the atherosclerotic plaque has not completely ruptured.
Another factor is the body's metabolism of caffeine. Approximately 50-60% of the population belongs to the "slow metabolizer" group, meaning caffeine remains in the bloodstream for a longer period. For these individuals, drinking just 2-3 cups of coffee a day can increase the risk of cardiovascular disease; if it reaches 10 cups, the risk is almost consistently high.
Dr. Hoang advises against consuming more than 400 mg of caffeine per day (about 4-6 cups of coffee), and less than 200 mg per day if you have cardiovascular disease. Preferably, drink coffee brewed through a paper filter, and limit drip coffee to reduce cholesterol-raising substances. It's best to drink it in the morning or early afternoon, avoiding after 4-5 PM.
Avoid combining high-dose coffee with smoking, alcohol, or prolonged late-night work. If symptoms such as rapid heartbeat, palpitations, chest pain, or shortness of breath appear after drinking coffee, stop using it and seek medical attention immediately.
"Coffee is not an 'enemy' of health. But when abused and combined with an unhealthy lifestyle, this familiar beverage can become a trigger for dangerous cardiovascular events," Dr. Hoang emphasized.