This question: “Is tea good for you?” is the one I am asked most often. As a lifelong lover and drinker of tea, I would say “of course tea is good for you!” But, as a scientist (I trained as a nutritional biochemist. Read more about me and my background here), I would say “it depends”. Read on to find out more, and to find out how to find reliable, up-to-date health information about tea. Everything in this article pertains to black tea, the fully oxidized form of the leaves of Camellia sinensis.
- Some black tea health facts
- Health benefits under research
- How to find reliable information about tea and health
- In conclusion
Some black tea health facts
First of all, there are some definite, proven facts about the positive role tea can play in a healthy diet. The following list comes from the Tea Advisory Panel, which you can read more about later in this article. These benefits include:
- The major component of tea as a beverage is, of course, water. One cup of tea provides about one-tenth of your daily fluid requirement.
- In the UK, and many other countries, tap water has fluoride added because it plays an important role in preventing tooth decay. The exact amount varies greatly depending on where you live, but tea itself naturally contains fluoride so tea makes a significant contribution.
- The average cup of tea contains about half the amount of caffeine as a cup of coffee.
- One cup of black tea provides around 30% of your daily manganese requirement, which is essential for bone growth and maintenance. It also contains small amounts, around 3% of your daily requirement of folic acid, vitamin B2, copper, magnesium, and potassium, all of which are vital nutrients.
- Black tea taken without milk contains no calories. Adding two tablespoons of semi-skimmed milk (2% fat) adds about 16 calories and 0.3g of fat. It also provides a small amount of calcium and vitamin B12 as well as other dietary minerals.
- Most of us drink tea because we enjoy drinking tea: it relaxes us, energizes us, provides us with a break from work, allows us to share time with friends and family. The culture associated with tea, especially in Britain, is that every situation, no matter how difficult, can be improved with a nice cup of tea and sit down. Therefore tea plays an important role in mental wellbeing and stress reduction. It is obviously difficult to quantify this benefit but increasingly we understand that mental health is vital to physical health so this benefit should not be overlooked.
Health benefits under research
Over the past several thousand years, much anecdotal evidence about the health benefits of tea has been collected. There is a huge amount of scientific research going on into the potential benefits of tea. There are claims about tea having a positive role in weight loss Chinese writings that are five thousand years old.
In the system of traditional Chinese medicine, black tea is said to reduce body fat, stimulate the central nervous system, enhance blood vessel strength, reduce fatigue and lower cholesterol.
Many of these claims, and more, for the health benefits of tea are now under active research by the Western scientific community. Some of these are:
- Heart health. A study published in 2002 which followed 4807 men and women found that the more tea a person drank, the lower their risk of heart attack (myocardial infarction) .
- Another study from 2008 found that tea provides benefits to the cardiovascular system as a whole, reducing the formation of atherosclerotic plaques, a key component of not just heart disease but also strokes and other thromboses .
- Diabetes. Type 2 diabetes is a disorder of glucose metabolism which is becoming increasingly common throughout the world. A study published in 2012 found that, as well as decreasing cardiovascular risk factors, black tea decreased fasting glucose levels . A more recent study published in 2014 found a lower risk of type 2 diabetes associated with drinking more than three cups of tea per day .
- Cancer. Over 50 studies of the association between cancer risk and tea consumption have been published since 2006. The results have been varied, but some have linked tea consumption to reduced risks of cancers of the colon, breast, ovary, prostate, and lung. Research is ongoing but at present, the National Cancer Institute of the USA regards the benefits of tea consumption in relation to cancer as “inconclusive” .
How to find reliable information about tea and health
It is important to note that many aspects of tea consumption and health will vary greatly depending on where you live. This is especially notable with regard to water quality and safety as water is the main component of tea. Here in the UK, we are fortunate to have safe, clean tap water which is constantly monitored across the country for many different factors that could affect health, from microbial content to dangerous pollutants such as arsenic.
Unfortunately for much of the world’s population, this is not the case. A 2016 article in the Wall Street Journal reported that in India, around 76 million people live without access to clean water: that’s more than the entire population of the UK. The same report noted that more than half of the population of three countries, Papua New Guinea, Equatorial Guinea, and Angola, have no access to safe water. This article took its data from a report published by WaterAid, a UK-based non-profit charity dedicated to improving water safety and sanitation around the world.
Back to tea. It is vital when looking for any health advice on the internet to understand the source of the information, and, most importantly, how it is funded. Ask yourself whether the site is just someone’s opinion, whether it is a site promoting tea (like this one!) or a more general health site, whether it is a site selling tea or funded by a tea company, and does it provide links to independent scientific studies?
In the UK, we are fortunate to have the Tea Advisory Panel, which provides independent and objective information about the benefits of tea. The seven scientists who make up the panel have long and distinguished backgrounds in medicine and nutritional science. This is a great starting point for finding out about the health benefits of tea.
As a lifelong lover of tea as a soothing and invigorating vital element of family and social life, tea is an essential part of my mental wellbeing. I never made a decision to drink tea because I was given it from when I was a baby (it was the first drink I had in a bottle) so to me, it’s like breathing.
However, the important point here is that before making changes to your diet because of perceived health benefits it is important to do your own research, find different sources of information and, if you can, talk to your doctor.
References (retrieved 5 August 2019)
 Geleijnse, J.M.; Launer, L.J.; Van der Kuip, D.A.; Hofman, A.; Witteman, J.C. Inverse association of tea and flavonoid intakes with incident myocardial infarction: The Rotterdam Study. Am. J. Clin. Nutr. 2002, 75, 880–886.
 Grassi, D.; Aggio, A.; Onori, L.; Croce, G.; Tiberti, S.; Ferri, C.; Ferri, L.; Desideri, G. Tea, flavonoids, and nitric oxide-mediated vascular reactivity.J. Nutr. 2008, 138, 1554S–1560S
 Bahorun, T.; Luximon-Ramma, A.; Neergheen-Bhujun, V.S.; Gunness, T.K.; Googoolye, K.; Auger, C.; Croziere, A.; Aruoma, O. I. The effect of black tea on risk factors of cardiovascular disease in a normal population. Prev. Med., 2012, 54S, S98-S102
 Yang J.; Mao Q.X.; Xu H.X.; Ma X.; Zeng, C.Y. Tea consumption and risk of type 2 diabetes mellitus: a systematic review and meta-analysis update. 2014, 4(7)
 National Cancer Institute, Tea and Cancer Prevention, last updated 2010