Overview
There is conflicting research-based evidence on the effects of caffeine on blood pressure and whether it is safe for hypertensive patients to drink coffee. However, most researchers believe that daily coffee intake can lead to a short-term increase in blood pressure. This article discusses the effect of caffeine on blood pressure and explores how drinking coffee affects blood pressure and the heart and whether drinking coffee is bad for the body.
Does coffee affect blood pressure?
Coffee can indeed affect blood pressure. Consuming 250-300 mg of caffeine daily typically results in a temporary increase in blood pressure. Research indicates that caffeine may cause a short but significant spike in blood pressure, even in individuals without hypertension. The exact reason for this increase is unclear. Still, it may be due to caffeine blocking a hormone that enlarges arteries or triggering the adrenal glands to release more adrenaline, raising blood pressure.
Some people who regularly drink caffeinated beverages have higher average blood pressure, while others develop a tolerance and experience no long-term effects on their blood pressure. A quantitative review found that coffee consumption can increase systolic blood pressure by 8.1 mm Hg and diastolic blood pressure by 5.7 mm Hg. These effects typically last for about three hours.
If you have high blood pressure, consult your doctor about whether you should limit or stop consuming caffeine. The U.S. Food and Drug Administration considers 400 milligrams of caffeine daily safe for most people. However, if you’re concerned about its impact on your blood pressure, try limiting your intake to 200 milligrams a day—roughly the amount in two 8-ounce cups of brewed coffee. Remember, caffeine content varies by brand and preparation method.
Avoid caffeine before activities that naturally raise blood pressure, such as exercise or heavy physical labor. To check if caffeine affects your blood pressure, measure it before and 30 to 120 minutes after drinking a caffeinated beverage. You may be sensitive to caffeine’s effects if it rises by 5 to 10 points.
If you decide to reduce your caffeine intake, do that gradually over several days to a week to avoid withdrawal symptoms like headaches.
Is coffee bad for high blood pressure?
Balanced coffee intake is generally considered safe for those individuals with high blood pressure. However, there are still mixed beliefs regarding the long-term and short-term effects of caffeine on the body.
Some researchers have concluded that caffeine blocks adenosine receptors and causes vasodilation at rest. Others believe that caffeine triggers the release of adrenaline, which causes vasoconstriction (narrowing of arteries). As a result, blood pressure increases.
Doctors often suggest patients avoid regularly consuming high amounts of caffeine as it can lead to physical dependence. But if you’re still concerned about coffee’s effects on blood pressure, you can talk to your provider to optimize the safe dose for your body.
Why might coffee help with blood pressure?
While coffee can temporarily increase blood pressure, it is also known to release chemicals like antioxidants and bioactive compounds that may be responsible for lowering blood pressure in many poeple.
The antioxidants in coffee, such as flavonoids, increase the production of nitric oxide, which dilates the blood vessels. Flavonoids also increase other minerals in the body, like magnesium, potassium, and vitamin E, which block the oxidation process and reduce excessive inflammation. Due to reduced inflammation and increased nitric oxide levels, the blood pressure will decrease.
How does caffeine consumption raise blood pressure?
The effect of coffee on increasing blood pressure is a bit complex as every body responds to it in a different way, depending on the frequency, dosage and sensitivity to caffeine.
Some specific doses of caffeine trigger the release of excitatory neurotransmitters of the sympathetic nervous system, such as norepinephrine and noradrenaline. These hormones cause an acute increase in blood pressure due to vasoconstriction.
Once the arteries are narrowed, there is a higher resistance in blood vessels which makes it harder for the blood flow. As a result, most people notice an increase in BP for a short amount of time, especially those who are not tolerant of consuming coffee daily.
People who regularly drink coffee develop a tolerance to caffeine and might not notice an increase or decrease in BP.
What effect does caffeine have on your heart?
Caffeine is believed to stimulate the heart due to the release of noradrenaline and norepinephrine hormones. Due to this, the heart rate and cardiac output both increase. In some people with underlying medical conditions, caffeine can disrupt normal heart rhythms, leading to arrhythmias.
Although latest evidence-based researches are very limited, it is widely believed that caffeine can have both short-term and long-term effects on the heart, ranging from increased heart rate and blood pressure to cardiac arrhythmias.
While moderate caffeine consumption is generally considered safe, you should consider speaking to your doctor to avoid potential complications.
When should I see a doctor?
If you experience any of the following scenarios after consuming coffee, you can visit your doctor right away:
- You notice an abnormal increase in blood pressure
- You’re experiencing persistent heart palpitations (rapid heartbeat)that aren’t returning to normal.
- You’re unable to sleep at night, have anxiety, or experience tremors.
- Experiencing stomach problems, indigestion, or heartburn.
It is important to talk to a doctor if you’re confused about the safe dose of caffeine as hypertensive patient. Also, if you’ve any underlying medical condition or you’re taking any medications, it is necessary to consult a healthcare professional right away.
FAQs about caffeine raise blood pressure
Caffeine has a half-life of 5 hours, meaning if you consume 100 mg of caffeine, after 5 hours, 50 mg will remain in your body. In a healthy adult, it generally takes almost 10 hours for caffeine to be completely eliminated from the blood system. However, the metabolism of caffeine can depend on various factors like pregnancy, kidney problems, smoking, or altitude.
If you’re taking blood pressure medication like beta blockers or verapamil, it is generally advised to avoid drinking coffee as it can interact with the absorption and metabolism of the drugs. You can talk to your provider to avoid the interaction and take coffee accordingly.
Yes, caffeine overdose can occur if you take more than the normal amount. A general safe dose of caffeine in healthy adults is 400 mg. Experts generally advise not to consume more than 600 mg, which is four to seven cups. An overdose of caffeine occurs if a person has 180 ml/L of caffeine in the blood. That means 40 cups of coffee is considered harmful to the body and can result in fatal consequences.
Yes, consuming a moderate amount of coffee of less than 400 mg in a day is generally considered safe in healthy adults without any medical conditions. However, if you suffer from any clinical condition like hypertension or diabetes or you’re pregnant, it is best to talk to your doctor about the safer dose of caffeine.
