Is green tea really a ‘miracle’ weight loss aid? We asked nutrition experts to find out

A STEAMING mug of green tea can do more than comfort you on a cold day or give you a hit of caffeine.

Studies have linked the grassy green liquid to a lower risk of type 2 diabetes and even slowed biological ageing.

The beverage has also been touted for its weight loss benefits, with studies seeming to show that drinking green tea might help improve your metabolism or burn fat.

Green tea contains caffeine and a type of antioxidant called catechin, with research from 2010 suggesting that both of these might help speed up your metabolism.

Another piece of research published in 2012 found that men who took green tea extract before exercising burned 17 per cent more fat than men who didn’t take the supplement, suggesting green tea could boost the fat burning effects of exercise.

But often studies on the health benefits of green weren’t conducted over long periods of time, and many based their results on green tea extracts rather than the drink itself.

So The Sun asked two nutrition experts to spill the tea on whether the much-loved beverage can actually help with weight loss.

Duane Mellor – a dietitian and Lead for Evidence-Based Medicine and Nutrition at Aston University – and Gunter Kuhnle, a Professor of Nutrition and Food Science at the University of Reading, discussed research into the drink and what other health benefits it could yield.

Does green tea actually help with weight loss?

Dr Mellor told The Sun: “Although there are reports of green tea helping weight loss, many of the studies are very limited and therefore there are no approved claims to say that green tea helps humans to lose weight.

But he added that “interestingly, mice studies seem to show green tea can help these rodents lose weight”.

His words were echoed by Prof Kuhnle, who called into question whether research showing that drinking green can lead to weight loss is as clear-cut as it seems.

“Green tea is often promoted for weight loss, but from the data I have seen and know, it’s likely to be small and therefore difficult to say whether it is really meaningful.

“So I’m not sure it is really useful for weight loss,” he stated.

Does drinking green tea have other health benefits?

According to Dr Mellor, it has been suggested that green tea contains beneficial plant compounds with antioxidant properties called polyphenols.

Epicatechins and an amino acid that is not found in protein called l-theanine are both mentioned.

Test tube studies on polyphenols have “mistakenly linked their antioxidant functions in the test tube with health benefits”, Dr Mellor said.

But he noted that “in humans, this effect is far less clear”.

Some studies suggest that l-theanine can help people to relax and be in a calm state of alertness, the dietitian said.

“However, currently the evidence in not conclusive and therefore no health claims can be legally made when marketing green tea.”

As for Prof Kuhnle, he said green tea might be linked to better memory and heart health.

“Green tea does contain a group of compounds – flavanols – which can reduce the risk of cardio-vascular disease, so there is a likely health benefit,” he told The Sun.

Writing for The Conversation, he discussed a study he helped conduct which that people who eat lots of flavanol-rich foods may have better memory compared to those who have a low intake.

Previous research also found that people with a low intake of flavanols were at higher risk of heart disease, Dr Kuhnle added.

What won’t green tea help with?

According to Dr Mellor: “Green tea can be an interesting and refreshing alternative to regular tea or coffee.

“It is slightly lower in caffeine than black tea and much lower in caffeine than coffee.

“It won’t definitely help with any health issues, as the best way to manage weight is by looking at what you eat and making sustainable changes.”

Prof Kuhnle noted that some people might suffer from an upset stomach after sipping on the drink, but he said “green tea is generally fine”.

But both he and Dr Mellor warned that green tea extract can be dangerous when too much is consumed, as it can cause liver damage.

The European Food Safety Authority recommends that you consume no more than 800 mg/d of green tea – “which is difficult with tea as a beverage, but easy with an extract”, according to Prof Kunle.

How often should I drink green tea?

Prof Kunle said you’d need to consume about two to three cups of green tea per day to reap its flavonol benefits.

As for Dr Mellor, he said: “It’s fine to drink 2-4 cups per day.”