Why that hot drink may be bad for you

Sticking the kettle on may be an appealing prospect when it is cold outside but be careful - drinking something hot after coming in from the cold may cause cracks in the surface of the teeth.

Sticking the kettle on may be an appealing prospect when it is cold outside but be careful - drinking something hot after coming in from the cold may cause cracks in the surface of the teeth.

Published Apr 2, 2015

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London - Many of us are so eager to have our cup of tea that we do not wait for it to brew properly, a University of London study revealed recently.

Researchers found that 40 percent of tea drinkers do not let the tea infuse for two minutes; the time needed to achieve the best flavour.

Not only will you miss out on the taste but there is also another potential problem with being impatient - you are drinking the liquid when it is still very hot, which, research suggests, could be bad for you.

For example, the heat and steam from your cup of tea or coffee can make blood vessels in the nose expand, says Henry Sharpe, a consultant ear, nose and throat surgeon at East Kent Hospitals University NHS Foundation Trust. ‘This can lead to weakening or rupturing of the vessels, causing nosebleeds. People prone to nosebleeds are particularly vulnerable, so allow your drinks to cool. We tell anyone who has had nasal surgery to avoid hot drinks for 40 to 72 hours.’

If you have had a nosebleed, avoid hot drinks for at least 24 hours as that is how long it takes for blood vessels to settle down, says Mr Sharpe. And here is what else that warming cuppa might do.

 

Is it safer to have milk in your tea?

Drinking steaming hot black tea has been linked with an increased risk of oesophageal cancer. The disease affects 8,000 people in Britain each year. In Europe it tends to be associated with smoking, obesity and alcohol, rather than hot drinks.

However, researchers at the University of Tehran have suggested that hot black tea may also be a risk factor. They studied the tea-drinking habits of 300 people diagnosed with oesophageal cancer and compared them with healthy people.

Nearly all of the participants drank black tea regularly; more than a litre a day on average. Very hot tea (at least 70degC) was associated with an eight-fold increased risk of the disease compared with drinking it warm or lukewarm (65C or less). Tea at 65 to 69C was associated with twice the risk, said the study, reported in the British Medical Journal.

It also found that drinking it in less than two minutes after it was poured was associated with a five-fold higher risk of cancer, compared with drinking it four or more minutes after being poured.

Previous British studies found that people prefer their tea between 56C and 60C, cool enough not to be risky (freshly boiled tea can be as hot as 100C).

Adding milk should cool the drink enough to eliminate the risk but it might be sensible to delay drinking herbal teas, which don’t usually have milk added, until they have cooled down. ‘The temperature and the speed at which the drink is ingested are the culprits, rather than the tea,’ says Dr Steven Mann, consultant gastroenterologist at Barnet Hospital.

One theory is that the high temperature causes damage to the lining of the oesophagus.

‘This damage means cells have to be regenerated. When that happens, cells can sometimes go haywire, triggering cancer,’ says Mr Sharpe. ‘The same thing happens with acid reflux, when the oesophagus is constantly exposed to acid splashing up the gullet.’

One very hot drink would be enough to scald the throat and gullet and damage the cells but damage could also build up over the years, says Dr Mann.

 

Hot drinks make skin conditions worse

People with rosacea may find that it gets worse when they have hot drinks. The condition, which affects one in ten people, causes chronic facial flushing.

‘Many patients in my practice find the redness gets worse when they drink hot drinks and improves when they replace them with cold drinks,’ says Dr John Ashworth, consultant dermatologist at Bridgewater NHS Trust, Cheshire.

This may be because a rise in body temperature affects the blood vessels around the body which regulate heat, including those in the face, he says.

 

When your teeth are at risk, too

Sticking the kettle on may be an appealing prospect when it is cold outside but be careful - drinking something hot after coming in from the cold may cause cracks in the surface of the teeth.

These superficial cracks, barely visible to the naked eye, are caused by rapid changes in temperature, from hot to cold, which can stress the enamel and result in a crack. If this exposes the dentine (a yellowish material that covers the pulp and tooth nerve) it can cause sensitivity or pain.

Severe cracks can damage the pulp or nerve, raising the risk of an infection or abscess. In cold weather, keep temperature changes to a minimum by wearing a scarf over your mouth, as this will warm the air you breathe. If you have sensitive teeth, perhaps from tooth grinding or brushing too hard, avoid hot drinks altogether, says Ilana Pine, a Manchester-based dental surgeon.

Teeth that have just been whitened may also feel sensitive, says Dr Pine, as the whitening process makes teeth more porous and dehydrated. As they rehydrate, they absorb liquid, so will be especially sensitive to hot drinks. ‘This should not last for more than 48 hours after the whitening treatment,’ says Dr Pine.

 

The dangers of polystyrene cups

Water of 69C is hot enough to cause third-degree burns, which destroy all the layers of skin in one second. That damage is irreperable, says Dr Ashworth.

In 2000, McDonald’s in America was sued by a 79-year-old customer, who was awarded $500,000 after spilling a cup of scalding McDonald’s coffee on herself, causing third-degree burns to her knees and lap. The court ruled the coffee had been too hot.

‘Cardboard and polystyrene are more of an insulating material, so they do not conduct heat away from the liquid. that is why the drink stays hotter,’ says Professor Peter Wilde, a research scientist at the Institute of Food Research.

‘Ceramic cups conduct more heat to the outside. That is why, while the cup feels hotter, the drink or liquid is actually cooler.’

If you spill hot drinks on your skin, it is important to apply ice or place the area under a cold running tap for ten to 15 minutes, says Dr Ashworth. The skin should feel cold to the touch and the redness should diminish.

Heat from a burn continues to damage the skin cells for some time; your body produces thick, fibrous material to help to repair the damage, causing scarring.

The quicker the skin is cooled down, the better.

You can’t put a dressing in your mouth so, if you do scald it, rinse with antibacterial, alcohol-free mouthwash or lukewarm salt water to soothe and promote healing, and prevent infection, says Luke Cascarini, a consultant oral surgeon at BMI The Sloane Hospital and the North-West London NHS Hospital Trust.

 

Could your tastebuds be destroyed?

Hot drinks can damage the tastebuds. ‘These are very delicate nerve endings around the tongue and they can get damaged like any other cells when exposed to very hot liquid,’ says Mr Cascarini.

‘Fortunately, the tongue is covered with millions of tastebuds so if it happens as a one-off, it shouldn’t really affect your sense of taste.’

Damaging the tastebuds can cause a rough, painful feeling on your tongue but it would take drinking hot drinks repeatedly and scalding the tongue extensively to affect taste sensation permanently.

 

PS... Hot coffee can make you kinder

On the plus side, holding a hot drink could make you seem more friendly.

in 2008, researchers at Yale University found that when people held a warm cup of coffee, they judged others to be more generous and caring.

If they had been holding an iced coffee, however, they took a less positive view towards others.

Another study from Yale found that people who are holding something hot instead of cold (in this case, heated or frozen therapeutic pads) are more likely to give something to others.

They were more likely to take something for themselves if they had been holding something cold.

The researchers believe that the insula (the part of the brain in which judgments about others are formed and also where we process warmth) is affected by an ‘agreeable’ temperature range.

The findings may also be linked to positive associations from cuddling our parents when we were young.

Daily Mail

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