Research about coffee and blood pressure is conflicting. However, it seems that how often a person drinks coffee could influence its effect on blood pressure.
Caffeine is a vasoconstrictor, which means that it decreases the size of blood vessels and can raise blood pressure. Caffeine exerts its effects by interacting with different receptors in the brain. Experts believe that other compounds in coffee, such as antioxidants, have a protective effect on blood vessels.
The benefits and risks of drinking coffee remain somewhat controversial, as the research to date is inconclusive.
Increased coffee consumption is associated with a small decrease in hypertension, according to a 2017 review. The researchers found a 9% reduced risk when drinking 7 cups per day, with a 1% decrease in risk for each additional cup per day.
The same review suggested that beneficial compounds in coffee, such as phenols, may have a protective effect. The researchers also noted that genetic variation among individuals could affect how they metabolize caffeine.
The review found that although there were older reports of a link between coffee drinking and hypertension, more recent studies suggested that 3–4 cups a day had either a neutral or beneficial effect.
A 2016 study of 40 healthy regular coffee drinkers found that all types of coffee increased blood pressure but that the levels stayed within healthy ranges.
The increase in blood pressure was temporary but still measurable 3 hours after consumption.
Some research suggests that the amount of coffee that someone drinks determines its effects on blood pressure.
A 2015 study indicated an increase in systolic blood pressure only in people who did not consume coffee frequently. Another review found that habitual coffee consumption of more than 3 cups a day did not increase the risk of hypertension. However, there was a slightly elevated risk associated with 1–3 cups a day.
As coffee contains many different compounds aside from caffeine, other compounds could be responsible for its effects on blood pressure.
However, a person could try switching to decaffeinated coffee to see whether their blood pressure decreases.
According to researchers, regular coffee drinkers may experience withdrawal symptoms, such as headaches and low mood, if they suddenly stop consuming it. Therefore, if they wish to reduce their consumption, they should cut down the number of cups gradually.
The authors of a review in JACC: Clinical Electrophysiology note that some doctors recommend that people with atrial fibrillation or other conditions involving an irregular heartbeat avoid coffee.
However, they concluded that a regular intake of up to 300 milligrams of caffeine per day appears to be safe and may even be protective against heart rhythm disorders.
The researchers cautioned, though, that if there is a clear association between arrhythmia episodes and caffeine, a person should not drink coffee.
Some alternatives to coffee contain caffeine, while others are naturally caffeine-free. People can try:
- chicory coffee
- dandelion root coffee
- rooibos tea
- yerba mate
- roasted barley or grain drinks
If someone experiences concerning symptoms when they drink coffee, they may wish to speak to a doctor. Those who notice an increase in blood pressure should seek medical advice.
Research suggests that people with high blood pressure can drink coffee as long as they are cautious.
Regular coffee drinkers may build up a tolerance to the physiological effects of coffee, whereas those who drink it less often may experience an increase in their blood pressure.
Coffee may be suitable for people with high blood pressure and could even have beneficial effects. However, people should be mindful of their tolerance for coffee and how their body reacts to caffeine.
If a person is concerned about their blood pressure, they should speak to a doctor.