Does caffeine raise blood pressure?
Moderate consumption of caffeinated drinks and foods is only rarely associated with long-term blood pressure elevation. Coffees and teas, thankfully, contain ingredients other than caffeine that are actually associated with improved medical outcomes.
Worldwide, about 90% of adults consume caffeine every day, in some form or other — most commonly in coffee, tea, soda and energy drinks. As such, caffeine is the world’s most popular stimulant. Meanwhile, more than 45% of people in the U.S. have hypertension, commonly known as high blood pressure. Since hypertension is dangerous in and of itself and can also precipitate a host of other cardiovascular diseases, the question "does caffeine raise blood pressure" is a pertinent one.
Fortunately, for the majority of us, caffeine only causes a short-term spike in blood pressure, and mostly in people who don't use it all the time. Additionally, there isn't enough evidence to prove that caffeine raises blood pressure over the long term. As (if not more) important, we don’t “drink caffeine”: Rather, we consume drinks or foods that contain caffeine and many other ingredients. Most notably, coffees and teas (and to a lesser extent, dark chocolate) contain substances, particularly phytochemicals, that have been shown to exert positive medical impacts on cardiovascular, metabolic, neurological and overall health; while it’s the sugars (and in some cases saturated fats) in or added to certain caffeinated food and drink products that appear largely responsible for negative health consequences.
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Understanding blood pressure
When your heart beats, it pumps oxygenated blood throughout your body, supplying vital nutrients and oxygen to your organs and tissues. The force generated by this pumping action creates pressure against the arterial walls, which is what we refer to as blood pressure (BP).
Your blood pressure is influenced by factors such as age, genetics, lifestyle choices, and underlying health conditions. When blood pressure is too high, it can put extra strain on your arteries and organs, increasing the risk of heart disease, stroke, and other serious health conditions. Conversely, low blood pressure can lead to dizziness, fainting, and inadequate blood flow to vital organs.
Understanding the two components of blood pressure, systolic and diastolic, allows for a more comprehensive assessment of your cardiovascular health. Systolic pressure, the higher number in a blood pressure reading, indicates the maximum pressure exerted by the heart during a contraction. Diastolic pressure, the lower number, represents the pressure in the arteries when the heart is at rest between beats.
Normal blood pressure typically reads as 120/80 mmHg. In 2017, the American College of Cardiology and the American Heart Association published new guidelines for hypertension management and defined high hypertension as a blood pressure at or above 130/80 mmHg. Stage 2 hypertension is defined as a blood pressure at or above 140/90 mmHg.
How is blood pressure measured?
Regular monitoring of blood pressure is crucial for identifying any potential issues early on and taking appropriate steps to manage and improve your cardiovascular health. By maintaining a healthy lifestyle — including regular exercise, a balanced diet, and stress management — you can help keep your blood pressure within the normal range and reduce the risk of developing cardiovascular diseases.
Blood pressure is often measured using a device called a sphygmomanometer, more commonly known as a blood pressure cuff. This can be done by a healthcare professional, or through a home blood pressure monitor. The cuff is wrapped around your upper arm and inflated to a pressure higher than your systolic blood pressure. This temporary constriction momentarily stops the blood flow in the artery. As the air is slowly released from the cuff, the doctor or healthcare professional listens with a stethoscope to the blood flowing through the artery, allowing them to gauge the pressure readings.
It is important to note that blood pressure readings can vary throughout the day due to factors such as physical activity, stress, and even the time of day. Therefore, it is recommended to measure your blood pressure at different times and under various conditions to obtain a more accurate picture of your cardiovascular health.
Causes of high blood pressure
Some people have high blood pressure caused by an underlying condition or drugs they are taking; this type of high blood pressure is called secondary hypertension, and tends to appear suddenly. But for most adults, there's no identifiable cause of high blood pressure, which tends to develop gradually over many years. Clinicians call this primary (essential) hypertension. Lifestyle factors can significantly up your risks of developing hypertension, particularly an unhealthy diet, low level of physical inactivity, obesity, excess alcohol and tobacco use, and high stress levels.
The dangers of high blood pressure
If your blood pressure stays abnormally high for too long (chronically), you are put at risk for many medical disorders, including cardiovascular disease (CVD), cerebrovascular diseases (e.g., stroke), kidney diseases and type 2 diabetes.
Mitigating your risks for high blood pressure, and the diseases which can develop from it, depends upon changes to your lifestyle, including dietary changes. If the hypertension persists, and other conditions develop, medications may be warranted, as well.
Read more about hypertension risks, causes, dangers, prevention and treatment:
7 ways to reduce stress and keep your blood pressure down
Cardiovascular disease prevention: What you need to know
Does caffeine raise blood pressure?
Caffeine, a naturally occurring stimulant found in coffee, tea, energy drinks, and chocolate, has long been a topic of interest when it comes to its effects on blood pressure. The relationship between caffeine consumption and blood pressure is multifaceted, with both short-term and long-term effects to consider.
Before delving into its blood pressure effects, we’ll make a few remarks on how caffeine works. This chemical exerts its effects primarily by blocking the neurotransmitter adenosine, which promotes relaxation and sleep. By inhibiting adenosine, caffeine causes alertness and wakefulness, making it a popular choice for those seeking a boost of energy. Caffeine also stimulates the central nervous system, increasing the activity of neurotransmitters such as dopamine and norepinephrine. This stimulation can lead to increased heart rate and blood pressure, as caffeine binds to adenosine receptors without activating them.
The effects of caffeine on the body
Beyond its ability to keep sleepiness at bay, caffeine has a multitude of effects on the body.
On the positive side, caffeine has been shown to:
- Improve mood and reduce fatigue
- Enhance cognitive function and increase alertness
- Boost metabolic rate and aid in fat burning
- Improve endurance and performance during exercise
- Lower the risks for type 2 diabetes, many cardiovascular diseases, Parkinson's disease, Alzheimer's disease, alcoholic cirrhosis, certain cancers (particularly colorectal and liver cancer), depression, and gout
Caffeine’s potential downsides, particularly at excessive levels, include:
- Anxiety, restlessness and jitters
- Gastrointestinal upset
- Disrupted sleep patterns, insomnia
- Headaches and irritability (as one abstains and experiences withdrawal symptoms due to the addictive properties of the chemical)
- Temporary increase in blood pressure
Effects of caffeine on blood pressure
Elaborating more on the last potential downside effect of caffeine, it is clear that some individuals may experience a temporary increase in blood pressure after consuming caffeine. So for these people, yes, caffeine does raise blood pressure. This is primarily due to caffeine's effect on vascular resistance and the force of cardiac contractions. However, it is important to note that the magnitude of this blood pressure increase varies among individuals. Some people may experience a more pronounced effect, while others may be less sensitive to the short-term impact of caffeine on blood pressure.
Additionally, if you're a regular caffeine drinker, your body may (and, in fact, usually does) develop a tolerance to these effects. Over time, the spike in blood pressure caused by caffeine may become less significant as your body adjusts to its presence. This tolerance can result in a diminished blood pressure-eating effect, making the short-term impact of caffeine on blood pressure less pronounced.
However, for those who are more sensitive to caffeine or have underlying health conditions, such as hypertension, the long-term impact on blood pressure may be more significant.
It is worth reiterating that caffeine is hardly the sole factor influencing blood pressure. Other lifestyle factors, such as diet, exercise, stress levels, and genetics, are believed to play considerably larger roles in determining an individual's blood pressure.
Caffeinated drinks and foods contain more than caffeine
While studies that isolate caffeine and its effects are important, remember that you’re not drinking a cup of caffeine; you are drinking a cup of coffee, or tea, or an energy drink, or eating a chocolate bar that may contain caffeine. But all of these food sources contain numerous other chemicals and nutrients.
Enter phytochemicals: The case for coffee and tea
Setting aside an analysis of energy drinks and chocolate, which contain varying (and often high) levels of caffeine and may also contain added sugars and other ingredients, let’s focus on coffee and tea since these categories represent two of the very largest sources of caffeine consumed worldwide.
While research is ongoing, and mechanisms still need further clarification, coffee and tea have been studied for decades: Overall, the news is good. Not only are their effects on blood pressure deemed of only minor concern (except for those that are either highly sensitive to such effects; or individuals who already have severe hypertension, such as blood pressure over 160/100), their effects on other physiological biomarkers is largely positive. The caffeine they contain is only a part of the equation, since both coffee and teas contain many other important ingredients.
Coffee and tea are rich sources of beneficial phytochemicals, including polyphenols, which are micronutrient compounds found in many plant food sources such as fruits and vegetables. The wide number of health benefits associated with many polyphenols have to do, in large part, with their antioxidant properties that reduce and help prevent free-radical activity in the body, which in turn is linked to improved cholesterol levels, improved blood pressure, reduced inflammation, and improved gut health — all of which ultimately support heart health, reduce risks for metabolic disorders (including type 2 diabetes), and stunt the development of cancer cells. The phytochemicals in both coffee and tea have also been found to aid in counteracting the negative effects of advanced glycation end-products, substances that become elevated by a diet high in animal proteins/fats and ultraprocessed foods. (Learn more: What is glycation?)
Coffee
What may surprise many people is hat coffee has a higher polyphenol content than any tea or red wine. Coffee contains 214 mg of polyphenols per 100 ml, whereas black tea and green tea contain 102 mg and 89 mg per 100 ml, respectively. Coffee contains chlorogenic acid and trigonelline, both of which exhibit cardioprotective effects. Consumption of chlorogenic acid is associated with reduced risk of hypertension, heart failure, atherosclerosis, and other cardiovascular conditions. Trigonelline improves cholesterols levels and reduces platelet aggregation, which, in excess, can lead to heart damage or strokes. Furthermore, as we detailed in our report, Coffee and diabetes, coffee has been shown to improve glucose metabolism by increasing glucose disposal or insulin sensitivity. Of the polyphenols found in coffee, chlorogenic acids (CGAs) appear to be the most potent in this regard; they have been shown to be protective against metabolic processes that could lead to inflammation and ensuing disorders (such as diabetes). Interestingly, coffee represents the richest dietary source of CGAs.
Here’s a snapshot of recent and important clinical trial findings on coffee and its health effects, including its impact upon blood pressure:
- In the large (over 20,000 adults) 2021 “Moli-sani Study” out of Italy, moderate consumption (3–4 cups/d) of Italian-style coffee was associated with lower risks of all-cause and, specifically, of CVD mortality. Study authors admit that the mechanisms explaining the beneficial effects remain unclear, although they propose it may have to do with the increased blood antioxidant levels witnessed, specifically the effects of caffeic acid and chlorogenic acid, two common catechol-containing coffee polyphenols; or an antiproliferative and antimetastatic activity by caffeine. Among other mechanisms, improved insulin sensitivity and reduced inflammation have been suggested as possible pathways by which coffee consumption may reduce the risk of chronic diseases.
- These results were in line with a 2019 meta-analysis of 40 prospective cohort studies that found lower risks of mortality from all causes and from CVD in a comparison of the highest versus lowest coffee consumption categories, with similar results across various subpopulations by characteristics of subjects, including age, sex, overweight status, alcohol drinking, smoking status, and caffeine content consumed.
As to high blood pressure (hypertension), specifically:
- A 2023 systematic review and meta-analysis found an inverse association between coffee consumption and hypertension risk in both cross-sectional and cohort studies. Overall, higher coffee consumption was associated with 7% reduction in the risk of hypertension, although authors caution that this association was dependent on varying study characteristics such as region of study, participants' sex, study quality, and sample size.
- A 2023 study published in Nature looked at over 9,000 subjects to determine the cardiovascular effects of coffee, and found that moderate and high coffee consumption correlated with lower systolic and diastolic blood pressure, but did raise LDL-cholesterol levels. The different levels of coffee consumption was not associated with altered cardiac function and morphology, heart failure, and most of its risk factors, nor did it correlate with any prevalent major cardiovascular diseases — connoting a neutral role of coffee in the context of cardiovascular health.
Teas
Teas do contain varying levels of caffeine, but they also contain catechins, polyphenols which are anti-inflammatory and preventative of oxidative stress, certain cancers, and neurodegenerative diseases.
Green tea contains the highest level of the catechin ECGC, or epigallocatechin-3-gallate, that in some research has demonstrated efficacy in reducing the risk of cardiovascular disease (CVD) and certain cancers. (Consuming green tea also has been shown to speed up fat breakdown, both at rest and during exercise, which indirectly may reduce CVD risks in overweight or obese individuals.) In addition, a body of research shows that green tea consumption is beneficial for controlling blood glucose levels. In one study, consuming green tea reduced fasting glucose levels, as well as hemoglobin A1c, a marker of type 2 diabetes (T2D). Subsequently, another study confirmed the reduction of fasting glucose levels, but not for the hemoglobin A1c marker. Lastly, while the findings are preliminary, the polyphenols present in green tea may also reduce cognitive defects associated with Parkinson’s and Alzheimer’s disease. Learn more: Health benefits of green tea.
Black teas, akin to (but with lower concentrations than) coffee, contain high concentrations of chlorogenic acid and theaflavins, polyphenols beneficial for reducing risks for T2D, certain cancers, certain neurodegenerative disorders, stroke, cardiovascular diseases, liver disease, and rheumatoid arthritis.
Preventing hypertension and managing blood pressure
So if it’s not coffee and tea that you should be watching out for so much, in regard to your blood pressure, what can you do to help prevent hypertension, or to manage an existing condition of it if you already have it? Clearly, it’s best to be fully evaluated and treated by your medical provider, particularly since your health profile is highly individualized, as are individual reactions to lifestyle changes such as dietary modifications. Medication strategies are also common and often advisable or even necessary.
Overall, however, there are several, highly recommended non-pharmacological strategies for managing BP:
- A healthier diet: Regarding blood pressure, it’s been deemed important to reduce your sodium intake, avoid ultraprocessed foods, refrain from excess alcohol consumption, and increase your intake of high-fiber, potassium-rich plant-based foods such as vegetables, fruits, legumes, whole grains, nuts and seeds. The potassium acquired by eating fruits and vegetables is one of the keys. (While most of us have heard that reducing salt in our diets can help lower blood pressure, research shows that it’s the ratio of sodium and potassium that matters most.) Many of these very same foods are also rich in B6 vitamins, folic acid, and magnesium (e.g., dark, leafy greens like spinach). Foods high in omega-3 fatty acids (e.g., salmon) are also beneficial.
- Weight management overall is of vital importance.
- Regular exercise, good sleep hygiene, and stress management also pay dividends when it comes to BP management.
We go into much greater detail on these and other blood pressure-reducing strategies in:
Cardiovascular disease prevention: What you need to know
7 ways to reduce stress and keep your blood pressure down
Salt and diabetes: What you need to know
Benefits of being a vegetarian: Are they actually healthier?
DoesWhat is cardiovascular fitness?
Key takeaways
So, does caffeine raise blood pressure? Most medical experts opine that — for the general population — consumption of up to 400 milligrams of caffeine per day (equal to roughly four cups of coffee, 10 cans of cola, or two “energy shot” drinks) is safe, as this level is not associated with any chronic, serious medical disorders. In fact, the most common sources of caffeine (coffee and tea) contain phytochemicals and other ingredients that contribute to such drinks reducing risks for several major diseases — including diabetes, heart disease, stroke, and certain neurodegenerative disorders and cancers. While caffeine intake may cause a temporary rise in blood pressure, long-term hypertension does not appear associated with moderate caffeine intake, except in cases where individuals already have severe hypertension or in individuals uniquely susceptible to caffeine’s BP effects. If you are at all concerned about caffeine’s effect on your BP, talk to your medical provider; it’s relatively easy to monitor your BP levels at home when drinking coffee or other caffeinated drinks or foods.
Note: Experts continue to advise that children avoid all caffeine drinks and foods, and adolescents and young adults need to be cautioned about excessive caffeine intake and mixing caffeine with alcohol and other drugs. Women who are pregnant or who are trying to become pregnant and those who are breastfeeding should talk with their doctors about limiting caffeine use to less than 200 mg daily.