After fresh water, tea is the most widely consumed beverage in the world, with over 3 billion cups consumed daily. The earliest archaeological evidence of tea consumption was found in China, dating back to around 200 B.C., with tea playing a pivotal role in economic and political development throughout human history.
As its popularity spread west towards Europe, tea became highly popular amongst the British middle and upper classes, leading to heavy taxation being introduced in 1689. British tea taxation would infamously be imposed on British colonies, leading to the Boston Tea Party in 1773 and setting a strong impetus for American independence in motion.
Tea plays a crucial economic role globally. The United Nations Food and Agricultural Organization (FAO) estimates annual tea production to be around $17 billion.
While tea has undoubtedly shaped the world we live in and continues to play a role in the lives of billions globally, we must ask ourselves whether tea is conducive to human health. Thankfully, a plethora of evidence attests to the safety of tea and its health benefits.
Health Benefits of Drinking Tea
Ancient Chinese civilizations were amongst the first to claim that tea had healing and medicinal properties. Until the sixth century B.C., tea was primarily considered a medicinal concoction in China. Modern medicine is continually attesting to the broad health benefits of tea.
Tea Is Full of Antioxidants
Chemicals found in green and black tea, known as catechins and theaflavins, give tea its antioxidant properties. Black, green, oolong and white tea, sometimes called the “true teas,” are all derivatives of the same plant, Camellia sinensis, but have been processed differently. Green tea has the highest content of catechins and, for antioxidant purposes, is the most effective tea. This is partly the reason for green tea’s primary association with health benefits when compared to the other true teas.
A comparative study published in the Toxicology journal found that one to two servings of black, green or oolong tea contained as many antioxidants as five servings of fruit and vegetables.
The benefits of antioxidants are diverse and vast, with research associating antioxidant consumption with:
- Protection from oxidative stress;
- Reduced rates of certain diseases;
- Improved mental health;
- Inflammation reduction.
Tea Consumption Can Reduce the Risk of Stroke
A stroke is a severe medical condition typified by an obstruction of blood flow to the brain, causing eventual cell death and neurological damage. Strokes are the fifth highest cause of death in the U.S., and many stroke survivors face a greatly reduced quality of life and a generally poor prognosis.
A Danish study of all stroke patients aged over 25 between 1982-1991 found that survivors had a 60% increased chance of death five years after their initial stroke. Additionally, 1 in 3 American adults has at least one of the leading risk factors for strokes — obesity, high blood pressure, high cholesterol, diabetes and a smoking habit.
Overwhelming medical literature supports the efficacy of tea in reducing the risk of stroke. A meta-analysis of studies published between 1966-2012, cumulatively involving over 500,000 participants, found a statistically significant association between tea consumption and a reduced risk of stroke. Drinking 3 cups of tea daily was associated with a 13% lower risk of stroke. Another meta-analysis involving nearly 200,000 participants found that consuming at least 3 cups of tea per day decreased the risk of stroke by 21%.
Tea Can Mitigate the Risk of Cardiovascular Disease
Cardiovascular disease is one of the leading causes of death worldwide. The World Health Organization (WHO) estimates it causes nearly 18 million fatalities annually, approximately 32% of all global deaths. The Centers for Disease Control and Prevention (CDC) estimate that heart disease costs the U.S. roughly $219 billion annually.
Reducing the risk of cardiovascular disease is one of the many health benefits of tea. A study of more than 82,000 Japanese men over the period 1995-2007 found that green tea consumption of 2 cups and upwards per day reduced the risk of cardiovascular disease. Furthermore, another Japanese study of over 76,000 men and women found that consuming black, green and oolong tea reduced cardiovascular disease mortality.
There Is Increasing Evidence That Tea Can Assist In Cancer Prevention
According to the CDC’s National Center for Health Statistics, cancer was the second leading cause of death in the U.S. in 2020, with just over 600,00 fatalities. Cancer is a particularly scary disease since it is notoriously difficult to treat sustainably.
Tea has shown some efficacy in prophylaxis (i.e., prevention) and in slowing down the progression of some cancers. Studies on animals have shown that tea can mitigate tumor transformation and the overall progression of the disease. A journal article published in The American Journal of Clinical Nutrition suggests that tea might have similar effects on humans as it does on animals regarding cancer. Moreover, the U.S. National Cancer Institute website suggests that tea may inhibit angiogenesis (i.e., the growth of new blood vessels required for the growth and spread of tumor cells).
While human-specific studies of the effects of tea in combating cancer are in their early stages, some have shown positive results. As modern medicine continues to search for an effective cancer cure, there is almost no harm in preventive tea consumption.
Tea Can Help You With Weight Loss
Green tea has long been touted as a weight loss supplement, and the evidence from research supports this belief.
Research conducted at the Pennsylvania State University’s College of Agricultural Sciences found that green tea increased metabolism in mice and achieved an average body mass reduction of 27.1%.
A Chinese study suggests that consuming different types of true teas daily, as opposed to one single type of true tea, may augment their weight loss benefits.
Frequently Asked Questions About Tea
Tea has been consumed by humans long before the advent of modern medicine and the scientific method. As such, it is important to separate fact from fiction when considering narratives surrounding tea and its uses, safety and benefits.
How Much Tea Can You Drink per Day?
Consuming more than 4 cups of tea per day can lead to adverse side effects, such as sleep problems, nausea, dizziness and impaired iron absorption.
How Much Tea Is Safe During Pregnancy?
Due to their caffeine content, the consumption of true teas should be monitored carefully during pregnancy. Pregnant women looking to get their fix of tea should consider switching to caffeine-free herbal teas until after giving birth.
Which Type of Tea Has the Most Caffeine and Which Has the Least?
People looking to regulate or limit their caffeine intake might be interested to know which of the true teas have the highest and lowest caffeine content, respectively.
Black tea has the highest caffeine content, with approximately 64-112 milligrams per serving. Contrastingly, white tea has the lowest caffeine content, with 32-37 milligrams of caffeine per serving.
For reference, a cup of brewed coffee has between 70-140 milligrams of caffeine, while a double espresso contains 125 milligrams.
Can Tea Expire?
According to an assistant professor at TUFTS University in Massachusetts, dried tea leaves can last up to two years before losing their flavor. Outside of losing flavor and changing in aroma, there is little to no danger in consuming expired tea, whether brewed with dry leaves or a teabag.
Are Tea Bags Good for Plants?
Tea leaves contain many of the same minerals as plant fertilizers, such as nitrogen and potassium, and can be used around your garden. It is best advised to remove the leaves from a used teabag before gardening. Using tea leaves will increase the acidity of the soil it is added to, so be sure to only use them for plants that thrive in acidic environments.
Tea Is an Ancient Medicine Fit for the Modern Age
Diverse cultures worldwide have fully embraced tea, and it seems that its popularity isn’t going to die down any time soon. Luckily, tea has a broad range of benefits that keep us healthy and prevent disease. Consider these benefits the next time you consider making yourself a cup of the world’s favorite beverage.