Research published in Advances in Nutrition, which examined 157 trials and 15 studies investigating how flavan-3-ols (present in tea) affect the human body, discovered that taking in 400–600 milligrams daily was the ideal quantity.

The study concluded: “Further, increasing consumption of dietary flavan-3-ols can help improve blood pressure, cholesterol concentrations, and blood sugar. Strength of evidence was strongest for some biomarkers (i.e., systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, and insulin/glucose dynamics).

“It should be noted that this is a food-based guideline and not a recommendation for flavan-3-ol supplements.”

The study identified the following as sources of flavan-3-ols:

A single cup of tea provides roughly 160mg of flavan-3-ol, which means that consuming three cups daily would fulfil the suggested daily intake. The Tea Advisory Panel (TAP) welcomed these findings.

Doctor Carrie Ruxton, a nutritionist and spokesperson for TAP, commented: “This is the first time in years that a so-called ‘non-nutrient’ is being recommended. What’s more, the recommendation has the goal of actually improving our health as opposed to simply keeping deficiency at bay, with the best part being that we can achieve this target simply by enjoying a few cups of tea.”

Other studies

Dr Tim Bond, a scientist, researcher and spokesperson for TAP, stated: “According to a study published in the Journal of Cardiovascular Pharmacology, flavonoids improve the performance of blood vessels – called ‘endothelial function’ – which helps to control blood pressure.

“By this action, flavonoid-rich foods such as tea, berries and apples can help to support cardiovascular health. Tea, with its rich flavonoid content, is therefore an important part of an optimal diet, particularly for heart health. It also provides healthy hydration.”

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Another study, published in Molecular Nutrition and Food Research in 2008, explored the antioxidant, anticancer, heart protective, antibacterial, antiviral, and brain protective qualities of flavan-3-ols.

Dr Bond said: “People can sometimes overlook the true power of polyphenols such as flavan-3-ols by describing them, perhaps too simplistically, as ‘antioxidants’. However, mounting research continues to show the benefits of consuming natural flavan-3-ols when it comes to reducing our risk of diet-related diseases, including heart disease, stroke, and type 2 diabetes.”

To reduce your blood pressure, the NHS recommends you:

• Keep to a healthy, balanced diet
• Take regular exercise – target at least 150 minutes of activity each week
• Shed excess weight if you’re carrying too much
• Cut back on salt – stay away from salty foods or adding salt to your dishes
• Reduce alcohol intake – don’t drink more than 14 units of alcohol weekly on a consistent basis
• Cut down on caffeine – beverages rich in caffeine include coffee, tea and cola
• Stop smoking

If you’re worried about your blood pressure, you should speak to your GP.