Heart Disease: Revealing the Truth About Coffee and Blood Pressure

Coffee is the most popular drink in the world. It is estimated that 2.25 billion cups of coffee are drunk around the world every day¹. 400 million cups are drunk in the United States alone. The world runs on caffeine. However, those with heart disease may be putting themselves at risk when they enjoy their morning cup of joe. In this article, we reveal the truth about coffee and blood pressure.

Hypertensive Heart Disease

Hypertension, or high blood pressure, is a condition where the force of the blood against the walls of the blood vessels is higher than normal². Chronically elevated blood pressure of 130/80 mm Hg is typically diagnosed as hypertension.

Hypertension affects many body systems by putting extra pressure on the arteries, causing them to become hard and brittle³. These brittle arteries don’t work effectively, reducing blood and oxygen flow to the heart and making them more prone to damage. When arteries harden and crack, cholesterol sticks to the damaged areas like a bandage⁴. In a healthy artery, cholesterol flows through without causing an issue. However, in a brittle, damaged artery this cholesterol can build up inside the arteries, increasing the risk of heart attack and stroke.

Hypertension can damage arteries, which poses a risk to kidney function. When the arteries around the kidneys are damaged, they can’t supply enough blood to the kidneys. This makes it difficult for them to remove waste and excess fluid from the body⁵. As excess fluid accumulates in the blood vessels, it further raises blood pressure, creating a vicious cycle that can eventually result in kidney failure.

According to the Centers for Disease Control (CDC) there are nearly half a million hypertension-related deaths per year in the United States⁶. Nearly 50% of adults have hypertension and only 1 in 4 have their blood pressure under control.

What is Coffee?

Making a delicious cup of coffee typically takes just a few minutes. However, the journey from coffee seed to your morning brew is much longer. A coffee tree usually starts bearing fruit, known as coffee cherries, about 3-4 years after planting⁷. The cherries are hand-picked when they turn bright red, then dried and milled to produce “green coffee.” This green coffee is then exported to manufacturers, where it is roasted, tested for quality, and finally sold to consumers.

The main components of coffee include caffeine, chlorogenic acid (CGA), trigonelline, various other acids, and small amounts of proteins, lipids, carbohydrates, and minerals⁸. Caffeine is the most prominent component. CGA, an antioxidant known for its health benefits, contributes to coffee’s flavor. Trigonelline and other acids are responsible for coffee’s acidic taste and pleasant aroma. While proteins, lipids, carbohydrates, and minerals are present only in small amounts, they contribute to coffee’s reputation as a healthful beverage.

Gut Health

On your journey to better understand your body you will find that the functions of the body are all tied together. Gut health and heart health are no exception. Science has found that individuals with high blood pressure have different gut bacteria than those who do not. Hypertension is associated with increased levels of pro-inflammatory and vasoconstrictive molecules and toxins which elevate blood pressure⁹. The relationship between gut health and blood pressure is yet to be completely understood. However, it has been established that people with an unhealthy gut microbiome are at a higher risk of developing or worsening hypertension.

While coffee cannot completely restore gut health, it can help. Coffee contains antioxidants called polyphenols. Several human studies have found that due to their anti-inflammatory nature, polyphenols positively affect blood pressure¹⁰. Some studies have also found that black coffee drinkers typically have a healthier gut microbiome than those who don’t. Caffeine triggers the gastrocolic reflex, causing the colon to contract and efficiently remove waste (stool) from the body¹¹. The quick removal of waste may be a key component to increased gut health.

Caffeine and Blood Pressure

The effects of caffeine on blood pressure are highly controversial. When evaluating this topic, some variables need to be considered, including:

• Dosage
• Consistency of consumption
• Age of consumer

Dosage

The evidence on how caffeine dosage affects blood pressure is mixed. Several epidemiological studies have found that long-term filtered coffee consumption did not significantly affect blood pressure¹². Conversely, observational studies suggest that consuming more than four cups of coffee per day may actually reduce the risk of hypertension, particularly in women. The biomechanics of why caffeine may benefit women more than men is not yet known. A separate meta-analysis of 11 randomized trials found that low dosages of caffeine raised systolic blood pressure. A high dose of caffeine raised both systolic and diastolic blood pressure. The effects of both dosages wore off within 3 hours or less.

Consistency of Consumption

How often coffee or any caffeine is consumed plays a role in how it affects blood pressure. Individuals who drink coffee more often are less affected by the caffeine as their bodies have become more immune to its effects. Caffeine has been found to raise both systolic and diastolic blood pressure more dramatically in those who do not consume coffee regularly.

Age of Consumer

A meta-analysis of caffeine consumers found that participants aged 24 and younger experienced an increase in systolic blood pressure of 5.31 mmHg and a 2.26 mmHg increase in diastolic blood pressure¹³. In contrast, participants aged 24 and older showed a smaller increase of 3.04 mmHg in systolic blood pressure and 2.55 mmHg in diastolic blood pressure. The effects of caffeine on individuals aged 70 and above have not been well-studied. However, this analysis suggests that caffeine may have a lesser impact on blood pressure in older adults compared to younger individuals.

The Truth About Coffee and Blood Pressure

The current science suggests no relation between caffeine intake and the development of hypertension. Individuals who have hypertension also do not seem to be at risk of worsening their condition by habitually drinking caffeine. Caffeine consumed with coffee has actually been found to have positive effects on gut health which could lead to better heart health.

Consumption of caffeine is highly individualized. Pay attention to how you feel within the first three hours of consumption. If your heart rate is elevated for extended periods of time after caffeine consumption, it may be time to switch to decaf.

Always speak to your doctor if you have any concerns with your blood pressure regardless of whether you do or do not have hypertension. Chronically elevated blood pressure can have life-altering consequences. It’s important to stop consuming caffeine at least six hours before bedtime. Caffeine can remain in the bloodstream for up to 10 hours, negatively affecting sleep quality, which can harm heart health.

Supporting Research

1. Gunter, M.J. et al (2017). Coffee drinking and mortality in ten European countries – the EPIC study. Annals of Internal Medicine 2017 Aug 15; 167(4): 236-247. Available from: Coffee Drinking and Mortality in 10 European Countries: A Multinational Cohort Study – PubMed (nih.gov) ↩︎
2. Understanding the Silent Killer: A Revolutionary Guide to Hypertension. Human Health Co. (2024b, August 12). https://humanhealthco.com/understanding-the-silent-killer-a-revolutionary-guide-to-hypertension/ ↩︎
3. Fuchs FD, Whelton PK. High Blood Pressure and Cardiovascular Disease. Hypertension. 2020 Feb;75(2):285-292. doi: 10.1161/HYPERTENSIONAHA.119.14240. Epub 2019 Dec 23. PMID: 31865786; PMCID: PMC10243231. ↩︎
4. Understanding the Silent Killer: A Revolutionary Guide to Hypertension. Human Health Co. (2024b, May 5). https://humanhealthco.com/understanding-the-silent-killer-a-revolutionary-guide-to-hypertension/ ↩︎
5. Shahoud JS, Sanvictores T, Aeddula NR. Physiology, Arterial Pressure Regulation. [Updated 2023 Aug 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538509/ ↩︎
6. Centers for Disease Control and Prevention. (2022, October 3). Health Topics – High Blood Pressure. Centers for Disease Control and Prevention. https://www.cdc.gov/policy/polaris/healthtopics/highbloodpressure/index.html#:~:text=High%20blood%20pressure%20(also%20known,have%20their%20condition%20under%20control.
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7. 10 Steps from Seed to Cup. National Coffee Association. (n.d.). https://www.ncausa.org/About-Coffee/10-Steps-from-Seed-to-Cup ↩︎
8. Saud S, Salamatullah AM. Relationship between the Chemical Composition and the Biological Functions of Coffee. Molecules. 2021 Dec 16;26(24):7634. doi: 10.3390/molecules26247634. PMID: 34946716; PMCID: PMC8704863. ↩︎
9. Tokarek J, Budny E, Saar M, Kućmierz J, Młynarska E, Rysz J, Franczyk B. Does the Composition of Gut Microbiota Affect Hypertension? Molecular Mechanisms Involved in Increasing Blood Pressure. Int J Mol Sci. 2023 Jan 10;24(2):1377. doi: 10.3390/ijms24021377. PMID: 36674891; PMCID: PMC9863380. ↩︎
10. Grosso G, Godos J, Currenti W, Micek A, Falzone L, Libra M, Giampieri F, Forbes-Hernández TY, Quiles JL, Battino M, La Vignera S, Galvano F. The Effect of Dietary Polyphenols on Vascular Health and Hypertension: Current Evidence and Mechanisms of Action. Nutrients. 2022 Jan 27;14(3):545. doi: 10.3390/nu14030545. PMID: 35276904; PMCID: PMC8840535. ↩︎
11. Miranda AM, Steluti J, Fisberg RM, Marchioni DM. Association between Polyphenol Intake and Hypertension in Adults and Older Adults: A Population-Based Study in Brazil. PLoS One. 2016 Oct 28;11(10):e0165791. doi: 10.1371/journal.pone.0165791. PMID: 27792767; PMCID: PMC5085083. ↩︎
12. Geleijnse JM. Habitual coffee consumption and blood pressure: an epidemiological perspective. Vasc Health Risk Manag. 2008;4(5):963-70. doi: 10.2147/vhrm.s3055. PMID: 19183744; PMCID: PMC2605331. ↩︎
13. Xu, Z., Meng, Q., Ge, X., Zhuang, R., Liu, J., Liang, X., Fan, H., Yu, P., Zheng, L., & Zhou, X. (2021, April 24). A short-term effect of caffeinated beverages on blood pressure: A meta-analysis of randomized controlled trails. Journal of Functional Foods. https://www.sciencedirect.com/science/article/pii/S1756464621001316 ↩︎