A cup of tea, or four, is a daily ritual for millions of Britons, and it is estimated that the country consumes around 165 million cups a day – about two and a half per person.
While there has been much talk about the overall health benefits of a drink, a recent study has raised the terrifying possibility that each tea bag may be releasing billions of potentially harmful plastic particles into the body.
But it’s far from the only health problem linked to a cup of tea. Here, MailOnline explains all the possible hidden health dangers.
Potentially carcinogenic and fertility-reducing microplastics
A shocking study this week suggested that each tea bag used to make a drink could be releasing billions of dangerous microplastics into the body.
Microplastics are small pieces of plastic less than 5 mm in length that have become increasingly abundant in the environment over time.
They are found in water, air and now in tea. Once in the body, microplastics can penetrate deeply into tissues thanks to their microscopic size.
While there has been much talk about the overall health benefits of this humble beverage, a recent study has raised the terrifying possibility that each tea bag may be releasing billions of potentially harmful plastic particles into the body.
In experiments, scientists from the Universitat Autònoma de Barcelona tested various tea bags made with nylon, polypropylene or polymer filters, mixing hot water with each one and testing the results.
They found that the microplastics released in the tea were mostly absorbed by mucus-producing intestinal cells.
However, they discovered that some were so small that they could even enter the cell nucleus, the part of the cell that houses genetic material.
While all were found to release huge amounts of microplastics, polypropylene tea bags were the worst, releasing approximately 1.2 billion particles per milliliter, each with an average size of 136.7 nanometers.
The implications of what microplastic exposure means for overall human health, both through tea and other routes, are still being explored.
But there is growing evidence to suggest that plastics could play a key role in the early genesis of cancer, where healthy cells become cancerous.
Some scientists have suggested that the presence of microplastics in tissues could be increasing the risk of cancer, including a mysterious increase in bowel cancers in young people.
Others have even found microplastics in human sperm and theorized that their presence could be influencing the global decline in fertility.
Small pieces of microplastic, seen here as black dots, were found in semen samples from 36 participants in a Chinese trial.
esophageal cancer
Drinking piping hot tea can double your risk of developing a type of cancer, some studies suggest.
Research on people in Iran found that those who regularly drank tea at a temperature of 60°C (140°F) or higher saw their risk of esophageal cancer increase by 90 percent.
The esophagus is the muscular tube that carries food and drinks down the throat to the stomach for digestion.
The theory is that repeated exposure to hot liquids damages cells, causing changes that could develop into cancer.
However, although it is intriguing, experts have highlighted that most Britons do not drink tea at this temperature due to the habit of adding milk, which cools it quickly.
Cancer experts have also said that if the increased risk posed by high temperatures is real, it is likely a cumulative effect of years of exposure to these scalding fluids.
This means that those Britons who have occasionally had a sip of tea that is too hot are probably not at a significantly increased risk of this type of cancer.
Drinking piping hot tea can double your risk of developing a type of cancer, some studies suggest
kidney stones
Oxalate is a natural chemical found in many types of plants, including tea.
While harmless to most people, one in 10 Britons prone to kidney stones should limit the amount of oxalate-rich foods and drinks they consume.
Having too much oxalate over a long period of time could contribute to the development of a stone.
While they are normally passed through urine without problems, larger kidney stones can be extremely painful and lead to infections or even affect kidney function if left untreated.
It is for this reason that the NHS advises people suffering from kidney stones to limit their consumption to just two or three cups of tea a day.
They also recommend consuming cups with a lot of milk, since the calcium it contains binds to oxalate, neutralizing it and helping to stop the development of stones.
Possible iron deficiency
Tannins are a type of natural chemical found in tea leaves that have been attributed several health benefits due to their antioxidant properties.
However, if you are one of the 8 per cent of British women or 3 per cent of men who are iron deficient, you may want to limit the number of cups you drink per day.
Microplastics aren’t the only potentially harmful substance scientists have found in tea bags.
This is because tannins can interfere with the way the body absorbs iron, which could make anemia worse.
If you are taking iron supplements, experts advise against consuming tea two hours before or after to ensure you absorb the iron needed to produce red blood cells that carry oxygen around the body.
Beware of hidden caffeine
When most people think of caffeinated drinks, coffee and energy drinks are usually the first things that come to mind.
But tea is also a little-known source of a stimulant that can come with a number of potential problems that some should be aware of.
While not as rich in caffeine as coffee, an average 200ml cup of tea still contains 45mg of the stimulant.
However, the exact caffeine content of tea can vary greatly due to factors such as brewing time, water temperature, and type of tea.
A Department of Nutritional Services report previously found that a cup of black tea contains between 23 and 110 mg of caffeine.
The NHS recommends that people consume less than 600mg of caffeine per day to avoid problems such as anxiety, insomnia, agitation, palpitations, diarrhea and restlessness.
However, Britons with certain sensitive heart conditions and taking medications that could interact with the stimulant may need to limit their caffeine intake, and this may include tea.
Pregnant women are also recommended to limit their caffeine consumption to just 200 mg per day due to the increased risk of miscarriage or low birth weight.
Pregnant women are also recommended to limit their caffeine consumption to just 200 mg per day due to the increased risk of miscarriage or low birth weight.
The stimulant is believed to cause blood pressure spikes that can influence blood flow to the placenta.
But some studies have suggested that even women who consume less than the 200 mg limit still have a higher risk of having low birth weight babies or premature newborns.
Other scientists have linked pregnant women who consume caffeine to children suffering from developmental delays.
However, this remains an area of scientific debate and some experts suggest that research linking consumption to problems is overblown.
But these experts added that pregnant women should still follow authorities’ guidelines on daily caffeine intake limits.
teeth discoloration
One of the most common complaints when drinking tea is tooth discoloration.
This is due to the high tannin content of the drink, which can cause the famous yellow stains.
While this can be unsightly and detrimental to people’s self-confidence, it is purely a cosmetic problem and can be mitigated by maintaining good oral hygiene.