Coffee is one of the world’s favorite drinks. Every day, billions of cups are consumed across homes, cafes, offices, and restaurants. For many people, coffee is more than just a source of caffeine. It is part of daily routines, social habits, and culture.
At the same time, coffee has also been surrounded by health questions for decades. One of the biggest concerns is whether coffee raises blood pressure and increases the risk of heart disease.
Scientists say the answer is not completely simple.
Coffee contains caffeine, a natural stimulant that affects the nervous system. After drinking coffee, many people feel more awake, alert, and energetic. But caffeine can also temporarily affect the heart and blood vessels.
Researchers explain that caffeine stimulates the release of adrenaline, a hormone that prepares the body for activity. Adrenaline can make the heart beat faster and cause blood vessels to tighten, which may increase blood pressure for a short time.
Blood pressure refers to the force of blood pushing against artery walls. Doctors measure it using two numbers.
The top number, called systolic pressure, measures force while the heart pumps blood. The bottom number, called diastolic pressure, measures force while the heart rests between beats.
Normal blood pressure is usually below 120/80 mm Hg. Consistently reaching 140/90 or higher is considered hypertension.
Hypertension is extremely common and often dangerous because it usually has no symptoms. Over time, uncontrolled high blood pressure can damage blood vessels and increase the risk of stroke, heart attack, kidney disease, and heart failure.
Researchers estimate that nearly one-third of adults have hypertension, and many do not know they have it.
Studies show caffeine can temporarily raise blood pressure after drinking coffee. Blood caffeine levels usually peak between 30 minutes and two hours later.
The amount of blood pressure increase varies between people. Some studies report systolic increases of 3 to 15 points and diastolic increases of 4 to 13 points after caffeine consumption.
However, scientists say temporary increases do not necessarily mean coffee causes long-term hypertension.
Many researchers have studied coffee consumption in large populations over many years. Surprisingly, many of these studies found little evidence that moderate coffee drinking directly causes chronic high blood pressure.
One major review examined 13 studies involving more than 315,000 people. Researchers found no strong link between coffee drinking and increased risk of developing hypertension over time.
The findings remained similar regardless of gender, smoking status, amount of coffee consumed, or whether participants drank caffeinated or decaffeinated coffee.
Scientists believe one reason may be that coffee contains many compounds besides caffeine.
Coffee is rich in natural plant chemicals known as phytochemicals. Some of these substances may actually help blood vessel function and circulation.
For example, compounds called melanoidins may influence enzymes that help regulate blood pressure. Another compound called quinic acid may improve the flexibility of blood vessels and help them respond more smoothly to changes in blood flow.
Researchers also note that regular coffee drinkers often develop some tolerance to caffeine over time. People who drink coffee frequently may experience smaller blood pressure increases than those who rarely consume caffeine.
Still, researchers caution that some groups of people may need to be more careful.
A long-term Japanese study followed more than 18,000 adults aged 40 to 79 for nearly 19 years. Among participants with very high blood pressure, drinking two or more cups of coffee daily was linked to roughly double the risk of death from cardiovascular disease.
However, the same increased risk was not seen in people with normal blood pressure or only mild hypertension.
This suggests coffee may affect people differently depending on their cardiovascular health.
Experts say people with severe hypertension, arrhythmias, liver disease, or certain heart conditions should discuss coffee intake with their healthcare provider.
Scientists also recommend avoiding coffee immediately before blood pressure checks because caffeine may temporarily raise readings and create misleading results.
Another important factor is sleep. Drinking coffee late in the day may interfere with sleep quality, which itself strongly affects blood pressure, heart health, metabolism, and stress levels.
Researchers generally recommend limiting coffee intake to around four cups or fewer per day for most healthy adults. Some people may tolerate more, while others may be more sensitive to caffeine’s effects.
The findings show that coffee is not simply “good” or “bad.” Its effects depend on many factors, including genetics, overall diet, medical history, stress, exercise, sleep, and individual sensitivity to caffeine.
Scientists continue studying coffee because it is one of the most widely consumed beverages in the world. Understanding how it affects health may help people make better decisions about their daily habits.
The study findings are valuable because they suggest moderate coffee drinking may not substantially increase long-term hypertension risk for most people, despite temporary rises in blood pressure after caffeine consumption.
One major strength of the research is the use of very large long-term population studies that followed participants for many years. The findings also highlight how coffee contains both potentially harmful and potentially beneficial compounds.
However, researchers still cannot fully explain why coffee may increase cardiovascular risks in people with severe hypertension while appearing relatively safe for others. Future studies may help scientists better understand how genetics, metabolism, and lifestyle influence individual responses to coffee.
If you care about high blood pressure, please read studies that early time-restricted eating could help improve blood pressure, and natural coconut sugar could help reduce blood pressure and artery stiffness.
For more health information, please see recent studies about added sugar in your diet linked to higher blood pressure, and results showing vitamin D could improve blood pressure in people with diabetes.
Source: The Conversation.
