Research Update: More Good News About Tea

The health benefits of tea have been of growing interest to scientists and researchers around the globe. Last year there were nearly 300 separate studies into the benefits of tea!

We’ve put together a round-up of some of the latest research. Some of these findings may encourage you to put the kettle on and have a cup of black, green or white tea instead of grabbing a coffee or a soft drink.

Tea May Help to Prevent Skin Cancer

Researchers in the USA using a white tea extract cream found that white tea can boost the immune function of skin cells and can protect them against the damaging effects of the sun.

The researchers believe that it is the antioxidant properties of white tea that produce the benefits and, if this is so, these same antioxidants may also have an anti-ageing effect. During the study, researchers also found that ingredients in green tea reduced the direct effects of sunburn.

Previous studies at the CSIRO in Australia have found that both black and green tea are protective against skin cancer when tested on mice.

Green Tea Supplement May Help the Fight Against Diabetes

Supplement manufacturer, Pharmanex, has been testing their green tea supplement, Tegreen, on rats. Scientists found that overweight rats who were treated with their supplement lost abdominal fat and had lower levels of fat, sugar and insulin in their blood.

Down the track, this may have health implications for humans in treating syndrome X and insulin resistance.

Tea Can Lower Cholesterol and Prevent Heart Disease

In another study, scientists found that when people who had a moderately high cholesterol took a green tea supplement, their LDL-cholesterol levels were reduced by as much as 16 per cent. LDL cholesterol is the ‘bad’ cholesterol, responsible for the build-up of plaque in the arteries.

However, it’s important to note that the antioxidant levels contained in the green tea supplement used in the trial is equal to approximately seven cups of green tea or 35 cups of black tea.

This is not the only study to find that tea can lower cholesterol though. Other studies have shown that polyphenols (a type of antioxidant) in tea can interfere with the molecules that cause the formation of LDL cholesterol. It has also been shown that polyphenols have anti-clotting effects and can relax the blood vessels, helping them to function better.

A Dutch study found that, compared to non-tea drinkers, tea drinkers had half the risk of having a heart attack and one-third of the risk of having a fatal heart attack.

Tea Can Prevent Cancer

A variety of studies have suggested that tea can reduce the risk of bladder, stomach, colorectal, oesophageal and oral cancers.

According to a 2001 study conducted at UCLA, the consumption of green tea can reduce the risk of developing chronic gastritis – a pre-cancerous condition that causes lesions.

Other research at UCLA has shown that green tea can reduce the growth of bladder cancer tumours in both rats and humans.

Tea has been shown to reduce the risk of oesophageal and rectal cancer by as much as 60 per cent.

Tea Can Make Your Bones Stronger

People who drink tea may also have stronger bones than their non-tea drinking counterparts. One study from Taiwan found that people who drank tea habitually for ten years or more had a hip bone density 6.2 per cent higher than those who did not drink tea. In Britain, women who drank at least one cup of tea per day were also shown to have a higher bone density.

Tea Can Boost the Immune System

Researchers from Harvard Medical School have found that tea can boost the immune system, helping to fight off bacterial infections. However, the researchers were quick to point out that tea isn’t a cure-all and that, even if you drink a lot of tea, you should consult a doctor if you become ill.

Tea has also been shown to help prevent the growth of bacteria on teeth, making it a good tool in the fight against cavities.

Drink Tea Moderately as Part of a Healthy Lifestyle

Before you start gulping away at 35 cups of tea a day, think carefully about your caffeine consumption when drinking tea. A strong cup of black tea contains up to 50 mg of caffeine. And remember that green tea contains caffeine too.

Dietitian Allan Borushek recommends limiting your caffeine intake to no more than 250 mg per day. The caffeine content of tea may produce a diuretic effect, however there is still a overall gain in fluid intake.

It is also important to note that drinking plain black tea with meals can prevent the absorption of iron from fruits and vegetables, although not iron from meat. You can add some lemon or milk to your tea to stop this from happening.

The flavonoids in tea also keep your blood from clotting as quickly as usual. If you are taking any medication to thin your blood, let your doctor know how much tea you drink as this may affect your required dosage.

Related articles:
Caffeine Counter
Caffeine and Your Health
Is tea good for me?

Last updated: September 2nd, 2003