Should people with cardiovascular disease drink tea with caffeine?
There have been opinions on both sides of the question about tea and heart disease. Should it be included in the recommended diet for a healthy heart? Or, does the caffeine in tea cause an irregular and elevated heart rate? This was a personal issue for me and was one of the reasons I became an avid tea drinker, giving up coffee when I realized that it was causing tachycardia. But I know that caffeine sensitivity can be an issue for some and should. But overall, the research into the benefits of including tea in a heart-healthy diet is fascinating. And two of the most common aspects of heart disease that have been studied in relation to tea consumption are high blood pressure (hypertension) and blocked/calcified arteries (atherosclerosis). And there are many general studies that associate diet with heart health.
The American Heart Association has funded and also published the results of many different studies supporting the benefits of drinking tea and heart health. The AHA is a fairly conservative organization so it’s especially important to consider their conclusions. In a nutshell, here’s what they found in a 2016 study of more than 6,000 subjects :
“Adults who drank one and two to three cups of tea daily had more favorable coronary calcium scores than those who never drank tea. They also noted a graded relationship between the amount of tea a person drank and a progressively lower incidence of major heart–related events starting with the one–cup–a–day tea drinkers, versus never tea drinkers.” They report that “coronary artery calcium progression (is), a marker for blood vessel disease, and heart attacks, angina, cardiac arrest, stroke and death from other types of heart disease.”
Tea and a heart-healthy diet.
What are some of the effects of the polyphenols like EGCG that support heart health?
These are some of the characteristics of tea that contribute to health and how they serve the body on a cellular level.
- Antioxidant – are substances that can prevent or slow damage to cells caused by free radicals.
- Anti-inflammatory – is the property of a substance or treatment that reduces inflammation or swelling.
- Antiproliferative – inhibits the cell proliferation as in apoptosis
- Anti thrombotic – reduces the formation of blood clots
- Vasorelaxation – a mechanism to widen blood vessels to enhance blood flow
In general, several studies have shown that tea drinkers who consume at least three cups a day enjoy a reduced risk of both heart disease and stroke. Specific observations note improved function of blood vessels, better circulation, and healthier cholesterol levels. One hypothesis is that tea functions as a vasodilator, opening the blood vessel walls, thereby reducing the risk of atherosclerosis, which is an indicator of high risk for cardiovascular disease. The body’s ability to maintain flexibility of the arteries is a critical factor to heart health. EGCG – Epigallocatechin gallate – inhibits the oxidation of cholesterol, a contributing factor to atherosclerosis.
What is atherosclerosis? How does drinking tea help?
Atherosclerosis is a chronic inflammatory disease of the blood vessels. Chronic means that the condition develops over time. It is the buildup of fatty material within the blood vessels. That restricts blood flow and is one of the primary causes of heart disease. It is made worse by some life choices like obesity, smoking, lack of exercise, and health conditions like diabetes, hypertension, and high cholesterol.
Diagram from NHLBI, Public domain, via Wikimedia Commons
“Tea and Hypertension
Hypertension – high blood pressure – is another form of heart disease that medical science is researching in relation to drinking several cups/glasses of tea daily.
Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure typically does not cause symptoms. Long-term high blood pressure, however, is a major risk factor for stroke, coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia. (Wikipedia)
And, while it is measurably true that caffeine intake elevates blood pressure acutely, and for a limited amount of time, there is research that tea can have a positive effect over a longer time of daily sipping. This may seem to be in conflict and is still being studied. But each one of us who has cardiovascular issues should consider how to balance potential benefits with possible harm. But studies like this 2019 begin to explain some of the benefits of tea on hypertension.
In summary, human interventions and animal studies have confirmed that both tea and tea metabolites have anti-hypertensive effects although some controversial reports existed. The underlying mechanisms include relaxing smooth muscle contraction, enhancing endothelial nitric oxide synthase activity, reducing vascular inflammation, inhibiting rennin activity, and anti-vascular oxidative stress based on ex-vivo tissue and in vitro cell culture studies.
Effects and Mechanisms of Tea Regulating Blood Pressure: Evidences and Promises” – Nutrients. 2019 May; 11(5): 1115. by Daxiang Li,1,2,† Ruru Wang,1,2,† Jinbao Huang,1,2 Qingshuang Cai,1,2 Chung S. Yang,2,3 Xiaochun Wan,1,2 and Zhongwen Xie1,2,*
Studying the health benefits of drinking tea
Studying the habits and lifestyle of real people living their daily lives is difficult. These are not tightly controlled laboratory conditions. Scientists know that, as much as they may try, it is nearly impossible to control the variables that may be affecting the results in ways that are not immediately obvious. To overcome this problem, many different studies studying a large number of diverse people, conducted in cultures around the world, are necessary. Over time, these different studies can be compared. We are now able to consider many of these kinds of studies to cautiously make some conclusions.
Conclusion; Considerations about Tea and Heart Disease
Heart diseases are a major cause of life-altering disease and death. The CDC estimates that approximately 600,000 people die annually of heart-related illnesses. While drinking tea cannot prevent or cure any cardiovascular illnesses, it can support an overall heart-healthy diet and provide energy for exercise and an active lifestyle. It would be inaccurate to say that drinking tea totally prevents heart disease. There are many causes of heart disease that cannot be addressed by diet and lifestyle. And it is not accurate to say that drinking tea will cure heart disease for much the same reason.
What’s Health About Tea; A series of 20 articles based on the book, “The Everything Healthy Tea Book”
- What’s The Healthiest Tea?
- A Glimpse of Tea’s Journey from Field To Cup
- EGCG: Understanding the Health Benefits of Tea
- Tea’s Power as an Antioxidant & Apoptosis Support
- Caffeine and L-Theanine In Tea
- Quantum Dots From Tea Extract Treat Disease
- An Overview of How Tea Helps Prevent and Fight Disease
- Tea And Cancer; The Evidence of Health and Well-Being
- Tea and Dementia; Can a Tea Lifestyle offer Protection Against Cognitive Decline?
- Tea & Dementia; A Tea Drinker’s Anti-Dementia Worksheet