All the reasons why you should swap your coffee for green tea

While many of us rely on coffee as a cognitive crutch to perk up our brain every morning, a recent Japanese study found that older people who regularly drink green tea had fewer lesions linked to dementia in their cerebral white matter.

Although coffee, with its 102-200mg of caffeine per 230ml (80mg per 230ml of instant), has been shown to have anti-inflammatory effects, it doesn’t have the same positive effect as green tea in the long-run, which packs a gentler 30-50mg per cup.

Earlier studies also show that green tea may even help you to lose weight, thanks to ingredients that promote the breakdown of fat cells. And while we’re likely to add milk, sugar or even syrup to a coffee – increasing calories – green tea is sipped in its purest form, keeping calories to a minimum and its antioxidant levels at a premium, Hobson advises.

Green tea contains an ingredient that boosts its health credentials above that of coffee. Made from steeped leaves and buds of the Camellia sinensis, green tea contains antioxidants called catechins, 80 per cent of which are categorised as a particularly beneficial type called epigallocatechin gallate (EGCG).

“Epigallocatechin gallate is the main antioxidant thought to bring the health benefits reported in the recent study,” explains Priya Tew, a specialist dietitian with Dietitian UK. “Free radicals are the molecules that can cause inflammation and damage to the body, antioxidants work by neutralising free radicals.”

The protective effects of green tea help your brain swerve something called “amyloid β” build-up. Amyloid β is the main component of plaque found in the brains of people with Alzheimer’s disease. “In addition to brain changes, green tea has a potential to lower blood pressure that could contribute to its protective effects, as this is a key risk factor for cerebral white matter lesions,” Rob Hobson, an award-winning nutritionist and author, advises. “Overall this makes it a better option for your morning brew.”

One cup is not enough to lower your risk though, says Tew: “This study shows that drinking green tea between three to eight times a day gives benefits.”

Green tea has far more to offer than simply supporting cognition. Hobson walks us through all its benefits.

Does green tea lower the risk of some cancers?

“Yes, the EGCG antioxidant found in green tea has been extensively studied for its ability to prevent certain types of cancer – particularly breast, prostate and colorectal cancers,” explains Hobson. “It’s thought to reduce the risk of abnormal cell division. It works by encouraging healthy cell death, and preventing the formation of new blood vessels that can support the growth of tumours.”

Does green tea help prevent heart disease?

Yes, there’s strong evidence that regularly drinking green tea can lower many of the risk factors associated with heart disease, including blood pressure and lipids, according to a 2022 review of studies.

“Green tea contains catechins and some other ‘polyphenol’ antioxidants that we think may improve blood vessel function. They are thought to keep veins, arteries and capillaries flexible, and that keeps blood flow efficient and prevents blockages, all of which contribute to better heart health,” says Hobson.

He also notes that the reduced amount of white matter lesions from the recent Japanese study is linked to vascular issues such as poor blood flow or high blood pressure. However, once again, more clinical evidence is needed to confirm the findings.

Does green tea help you lose weight?

There is evidence to suggest that green tea contains substances that boost metabolism, helping to break down fat cells, with several studies backing up this correlation.

The antioxidant EGCG plays a role here too, as it works to increase the levels of norepinephrine, which promotes the breakdown of fat cells. The catechins green tea contain, as well as the caffeine, also help break down fats in a process called fat oxidation.

There’s a distinction to be made between drinking green tea and taking green tea supplements – which is what some participants in these studies were doing.

“Supplements are concentrated and standardised to provide much higher doses of catechins. This makes supplements useful in studies looking at specific health effects but something to be aware of when looking at the results of the research,” says Hobson.

He admits: “Some studies have shown small reductions in body weight or fat mass with green tea supplementation, especially when paired with dietary and exercise interventions, but reducing your food intake, improving the quality of the food you eat and being more active would also be required.”

In other words: put the kettle on before you knuckle down to do the rest of the hard work needed to maintain a healthy weight.