Coffee has been part of human culture for over 600 years and remains one of the world’s most popular drinks today.
On average, people now consume about 2 kilograms of coffee per person per year, and many have strong opinions about brewing methods, beans, and blends. Genetics also influences how much coffee people enjoy, which can influence both caffeine metabolism and the brain’s reward system.
Coffee can temporarily increase blood pressure, especially in people who don’t drink much coffee or who already have high blood pressure. But that doesn’t mean you need to cut coffee out of your daily routine if you’re concerned about your heart health. For most people, moderation is more important than avoiding it completely.
So how exactly does coffee affect blood pressure, and what amounts are considered safe?
What is high blood pressure?
Blood pressure measures the force with which blood pushes against artery walls as the heart pumps. Doctors track it using two numbers:
- Systolic blood pressure (the higher number) measures the pressure when the heart contracts and pumps blood around the body.
- Diastolic blood pressure (the lower number) measures the pressure when the heart relaxes between beats.
A healthy blood pressure reading is less than 120 millimeters of mercury (mm Hg) systolic and less than 80 mm Hg diastolic.
Readings that consistently reach 140/90 or higher are classified as high blood pressure, also called high blood pressure.
High blood pressure is sometimes referred to as a silent condition because it usually does not cause symptoms. If left untreated or poorly managed, it can increase your risk of heart attack or stroke and worsen existing heart or kidney disease.
Approximately 31% of adults have high blood pressure, but about half are unaware that they have high blood pressure. Among people taking high blood pressure medication, about 47% still have uncontrolled blood pressure.
How caffeine increases blood pressure
Caffeine is a muscle stimulant and can increase heart rate in some people. In some cases, this can cause irregular heartbeats called arrhythmias.
It also stimulates the release of adrenaline from the adrenal glands. This reaction can cause your heart to beat faster, your blood vessels to narrow, and your blood pressure to rise.
Caffeine levels in the bloodstream typically reach their peak between 30 minutes and 2 hours after drinking coffee. The half-life is 3 to 6 hours, during which time the amount in the blood decreases by about half.
There are several factors that affect how quickly your body processes caffeine. Age is important because children have smaller and less developed livers and are slower to metabolize caffeine. Genetics also plays a role, as some people naturally break down caffeine faster than others. People who drink coffee regularly also tend to remove caffeine from their bodies more efficiently.
Research reviews show that caffeine found in coffee, colas, energy drinks, and chocolate can increase systolic blood pressure by 3 to 15 points and diastolic blood pressure by 4 to 13 points after consumption.
This effect may be more concerning for people who already have high blood pressure or who already have heart or liver disease. People with these symptoms should talk to their doctor about consuming caffeine.
Coffee contains more than just caffeine
Coffee is made up of hundreds of phytochemicals, compounds that provide flavor, aroma, and potentially health effects.
Some of these compounds can directly affect blood pressure. For example, melanoidins help regulate enzymes involved in regulating body fluid balance and controlling blood pressure.
Another compound called quinic acid is associated with lower systolic and diastolic blood pressure. Researchers believe this may allow blood vessels to work more effectively and better cope with changes in pressure.
Does coffee increase the risk of high blood pressure?
Researchers took a closer look at whether coffee actually causes long-term high blood pressure.
One review combined data from 13 studies involving approximately 315,000 people. During the follow-up period, 64,650 participants developed hypertension. Overall, the researchers found no clear link between coffee consumption and an increased risk of developing high blood pressure.
The results were consistent regardless of gender, coffee intake, caffeinated vs. decaffeinated coffee, smoking habits, and study period.
Five studies conducted in the United States and seven lower-quality studies showed some low-risk findings, but the researchers noted that these results should be interpreted with caution.
Another study conducted in Japan followed more than 18,000 adults between the ages of 40 and 79 for about 19 years. Approximately 1,800 participants had very high blood pressure (grade 2-3 hypertension), defined as systolic blood pressure of 160 or higher or diastolic blood pressure of 100 or higher.
In that group, those who drank two or more cups of coffee daily had twice the risk of dying from cardiovascular disease, including heart attack and stroke, compared to those who did not drink coffee.
Researchers did not find a similar increased risk among people with normal blood pressure or mild (grade 1) hypertension (systolic blood pressure 140-159 or diastolic blood pressure 90-99).
Coffee and blood pressure conclusion
Most people don’t need to give up coffee completely. Instead, experts recommend paying attention to your overall health, caffeine intake, and blood pressure levels.
Here are some helpful steps:
- Know your blood pressure numbers, health history, and foods and drinks that contain caffeine
- Consider all factors that affect blood pressure, including family history, diet, salt intake, and physical activity
- Avoid consuming caffeine before your blood pressure test as it may temporarily affect the results.
- Avoid caffeine later in the day if it interferes with sleep
- Limit your coffee intake to less than four cups a day or consider switching to decaf.
- If your systolic blood pressure is above 160 or your diastolic blood pressure is above 100, consider limiting your coffee to one cup a day and talk to your doctor.
