How to eat green, drink it, and love it
Green tea has long been a favorite among health-conscious travellers, but for some, its nutritional benefits are harder to see.
A new study from the University of Edinburgh suggests that its antioxidant effects are being overlooked by the general public, with only a handful of studies published to date.
The findings, which were published in the journal Scientific Reports, suggest that green tea’s ability to improve blood flow and reduce inflammation may be down to its anti-oxidant properties.
“There’s a lot of misinformation out there about the benefits of green tea,” said lead author Dr. Helen Cattaneo.
“We wanted to look at the nutritional benefits of the plant.”
Dr. Cattano, a professor of internal medicine at the University’s College of Medicine, and her colleagues conducted a study in which they analysed green tea extracts and analysed their antioxidant properties.
In this study, they looked at the antioxidant properties of eight different extracts, which ranged in strength from 0.1mg to 100mg per ounce.
The extracts were analysed using a technique called spectroscopy, in which a laser was focused on an atom in a liquid to measure its magnetic properties.
The researchers then analysed the compounds that were extracted and the resulting molecules were then compared to the compounds in the actual tea, in the form of an extract.
The researchers found that the antioxidants were significantly more effective in green tea than in the extract.
“Green tea contains a wide range of flavonoids that are thought to help the body regulate its metabolism,” said Dr. Caccaneo, who is a co-author on the paper.
“It is well known that flavonoid concentrations increase when people eat green tea and also when they drink green tea.”
Dr Cattaniello explained that the research suggests that green teas have different antioxidant properties depending on the amount of flavanols and caffeic acids they contain.
“Our data suggests that flavanol concentrations in green tea extract are more protective than those of tea, and that these protective effects are mediated by flavanones in the green tea extract,” she said.
While green tea may help regulate the body’s metabolism, it may also play a role in preventing heart disease and diabetes.
“We also found that green leafy vegetables, such as spinach and broccoli, have an antioxidant effect,” Dr. Cecilia O’Donnell, a postdoctoral researcher at the Edinburgh Centre for Advanced Functional Genomics, said.
“The antioxidants in these vegetables may act to protect against oxidative stress and inflammation, while also helping to improve the cardiovascular system.”
Dr O’Brien also said that green vegetables may offer a potential treatment for type 2 diabetes.”[It] may be that some of the benefits from green tea can be directly transferred to type 2 diabetics, because the antioxidant effect of green leaves is more powerful in diabetically active people than it is in people who are not diabetatic,” she added.
“In particular, we think the antioxidant effects of green leaf and white tea may have a therapeutic role for type 1 diabetes.”
Green tea extracts can be used in many different ways, including flavouring food, and Dr Cattani said she was not aware of any scientific research to support claims that the extract is a powerful anti-inflammatory agent.
“As we’ve been using these green teases for decades, they’re very effective at reducing inflammation and reducing oxidative stress,” she explained.
“So, this is really about improving the immune system and increasing your ability to heal, and as long as you’re doing this in the right context, it’s quite likely that the anti-inflammatories that you get from green tease are doing that.”
While the study shows that green leaves may have antioxidant properties, Dr Caccaniello said it was important to understand how the extracts are used.
“You’re probably more likely to be using green teabags than tea bags or green teaware or green tea bags,” she advised.
“It’s better to use green teapigs than tea bag greens.
I wouldn’t recommend tea bags and green teawas for a healthy lifestyle.”
The research was funded by the Scottish Government’s Natural Environment Research Council, the University College of Scotland, and the Scottish Science and Technology Centre.