There’s no doubt we’re a nation of tea-lovers – and apparently we’ve been getting through an extra two cups a day during the pandemic. That’s on top of the average four to six cuppas a day we normally drink.
It’s little surprise, then, that the Tea Advisory Panel (Tap) found 80% of people say tea provides relief from daily problems and stresses.
Tap says tea contains natural plant substances, including polyphenols, caffeine and amino acid L-theanine (a building block of protein) which act on the body and mind. A recent major review found L-theanine improves the ability to manage stress and anxiety, and earlier studies have shown it triggers various parts of the brain linked with relaxation and mental focus to light up, helping us deal with distractions.
“We often turn to tea when in need of a boost or to help us handle stress,” says dietitian Dr Carrie Ruxton. “Whether it’s a comforting mug of tea with family, or the peaceful ritual of brewing up some tea leaves in your favourite teapot, tea always seems to do the trick. Yet we know from the science that it’s not our imagination, as there are now several studies pointing to the mental health benefits of drinking tea every day.”
One study, she says, asked participants to drink black tea or a placebo drink daily for six weeks, and were then asked to complete a series of stressful mental tasks. The tea drinkers were found to have lower levels of stress hormones in their blood, and reported feeling more relaxed after the tasks.
Fellow Tap member Dr Tim Bond adds: “Tea is a healthy drink and can make a useful contribution to our daily fluid requirements and help maintain good hydration during lockdown.
“Tea may contribute to immune function, partly due to a beneficial effect on the gut microflora. It’s a pleasant, comforting drink and can help us feel better during this time of stress and uncertainty. Enjoying four to six cups daily is good for our physical and mental health.”
Dr Bond outlines the science.
It may reduce or delay dementia risk
A study of 957 elderly Chinese people found consistent drinking of black/oolong tea reduced the risk of cognitive disorders by 53%, and for green tea by 43%. The findings also suggested those genetically at higher risk of developing Alzheimer’s disease may reduce this by as much as 86%. “This health benefit is likely to be due to the catechin content of tea,” says Bond.
A laboratory study found the dominant member of this catechin family could reduce the cognitive defects linked with a Western diet high in fat and sugar, and Bond says further research has found a positive contribution of tea drinking to brain structure, suggesting a protective effect on age-related decline in brain organisation.
It enhances cognition and memory
A review of 49 human studies found two ingredients in tea – L-theanine and caffeine – in combination are associated with improved attention, memory and alertness more than either ingredient on its own.
It helps reduce depression and anxiety
Another 2018 study found long-term tea consumption among elderly people was associated with reduced symptoms of anxiety and depression. Theaflavins, compounds found in black tea, have been found to reduce depression and prevent memory impairment. Theaflavins have also been shown to reduce anxiety by increasing dopamine turnover in the brain.
It lowers the risk of cardiovascular problems
A review published in 2012 found regular tea consumption could reduce the risk of heart and circulation problems by up to 20%. Some studies have found this effect could even be as high as 45%. In one 2019 study of 208 patients, tea drinking was linked with reduced arterial disease compared with soft drinks, which were linked with increased arterial disease.
It helps prevent type 2 diabetes
Studies also indicate the beneficial effect of being a regular tea drinker in relation to type 2 diabetes – particularly green tea. A study published recently by Cambridge University Press, of 12,017 people aged 20-70, found daily tea drinking reduced diabetes risk in women by 32%. Dark tea reduced the risk by 45%.
It helps with weight management
Scientists are increasingly understanding the role of gut bacteria in obesity and weight management. A 2017 University of California study found both black and green tea changed the ratio of intestinal bacteria. The percentage of bacteria associated with obesity decreased, while bacteria associated with lean body mass rose. This change in the gut microflora was associated with increased energy metabolism.
It helps tackle high blood pressure
A study published in 2012 found drinking black tea could have a 10% effect in reducing blood pressure, while separate research found regularly drinking green tea could reduce the risk of high blood pressure by 46%. “Tea and its compounds have been shown to help relax smooth muscle and reduce inflammation in arteries, which may help to explain these effects on blood pressure,” explains Bond.
It’s good for oral health
“There’s evidence tea can combat bad breath and reduce inflammation, bone reabsorption and the growth of bacteria associated with gum disease,” says Bond. One study found tea helped with a 40% reduction in dental decay risk.
It’s good for eye health
Research also shows daily tea drinking could reduce the risk of developing glaucoma and cataracts, among the most common potentially sight-threatening eye conditions. Tea catechins may also protect against age-related macular degeneration, says Bond.
It keeps bones strong
“Tea drinkers tend to have stronger bones,” says Bond, who explains that researchers report that tea appears to improve bone mineral density, especially in the spine, hip and neck. A further study also found tea consumption may help reduce the risk of osteoporosis.
