The health benefits of tea have been revealed in a slew of new research (Image: Getty)
If you’re one of the millions of Brits on a slow burn towards poor health, new research shows that something as simple as enjoying three or four cups of tea a day could dial down your risk of dozens of serious health issues. Systemic inflammation – a long-term, low-level and body-wide immune system malfunction which places the body on constant alert – is emerging as a key contributor to dozens of chronic physical and mental health conditions, including cardiovascular disease, diabetes, arthritis and other joint problems, dementia, depression and anxiety.
But a study just published in journal Food and Nutrition Sciences shows that drinking tea regularly could help dial down this corrosive inflammatory response and those at highest risk are the most likely to benefit from a brew. The research review, which analysed evidence from 22 papers, including 11 clinical trials, found: “Black tea with or without milk appears to have a potentially beneficial role in a range of conditions with inflammatory origins.”
And it concludes: “Given its low cost, wide availability and cultural acceptance, black tea could represent a simple adjunct to dietary strategies for reducing systemic inflammation.”
Persuading patients to change lifestyle can be a big ask… but suggesting extra cups of tea isn’t (Image: Getty)
Public health nutritionist Dr Emma Derbyshire, one of the co-authors of the new paper and a member of the Tea Advisory Panel, says: “Until now, a lot of the research around potential benefits of tea-drinking has focused on green tea, or looked at both black and green tea. However, in the UK, black tea, with or without milk, is by far the most popular, and although they are both derived from the same plant, Camellia sinensis, they are processed differently and we know this impacts their polyphenol profile, so we wanted to isolate the evidence.”
And the good news is that the evidence confirms that Britain’s favourite cuppa really is a cup of good health.
Hearty findings
A study of more than 84,000 patients with cardiovascular disease found that systemic inflammation increased their risk of a major “event” such as a heart attack or stroke by 30% and the likelihood of heart failure by 24%. Evidence of the link between systemic inflammation and cardiovascular disease is now so strong, last year the American College of Cardiology called for universal screening to identify adults at high risk of disease due to systemic inflammation.
And there’s also compelling evidence that drinking black tea can reduce this risk. A meta-analysis study published last year which looked at data from 14 studies involving 958,477 people, found that compared to those who didn’t drink black tea, those who enjoyed four cups a day reduced their risk of coronary heart disease by 11% and six cups cut it by 14%.
Dr Gill Jenkins, a GP with a special interest in diabetes and many of the lifestyle health issues associated with chronic inflammation, explains: “There are more than eight million people in the UK living with cardiovascular disease, and it’s estimated over half of us will develop a cardiovascular condition in our lifetime, so anything to reduce this risk could have a big impact on the nation’s health.
“What makes the link between tea and improved health even better is it’s advice that is easy to act on. It’s often a big ask to persuade patients to change their diet or lifestyle, but suggesting they take time out for a few cups of tea is an easy win.”
Cancer connection
UK Biobank data from more than 440,000 people found that systemic inflammation was associated with an increased risk of seven cancers and this was particularly pronounced for bowel and lung tumours. Another study, in more than 31,000 cancer survivors, found a “strong positive correlation” between raised inflammation and death from any cause. The authors concluded: “Inflammation plays a crucial role in cancer biology by influencing tumour progression, metastasis, and the response to treatment.”
Amino acids found in high concentrations in black tea have been found to inhibit oxidative damage (Image: Getty)
Look out for signs on an inflammation issue
In the short term, inflammation is an important immune defence which helps our body deal with infection or injury. But as the paper explains: “While inflammation may initially provide a protective response, prolonged inflammation can have detrimental effects on health.”
Dr Gill Jenkins says: “It’s an insidious condition because it often creeps up on people slowly, and the most common symptoms are everyday issues which we tend to put down to having a busy lifestyle.These telltale signs include fatigue and lack of energy, headaches, depression, anxiety, changes in weight or appetite; constipation, diarrhoea and other gastrointestinal problems; muscle aches and joint pain, and ‘brain fog’ or feeling generally a bit fuzzy mentally.”
Our lifestyle choices can also have a huge impact on levels of systemic inflammation, with poor diet, obesity, lack of exercise, low intakes of omega-3 fatty acids, smoking, alcohol consumption and disrupted sleep all known to increase the risk of systemic inflammation.
Green tea has long been hailed for health benefits – but traditional tea is just as good (Image: Getty)
Dr Tim Bond, a researcher, chemist and member of the Tea Advisory Panel, says many health benefits associated with a brew are down to the polyphenols found in tea. He explains: “Tea polyphenols can help defend against harmful molecules that damage cells, while also boosting the body’s antioxidant defences. They may also reduce activity in some of the main biological pathways that trigger inflammatory response.”
Immunity issues
Inflammation and raised inflammatory markers such as C-reactive protein (CRP) are a hallmark of autoimmune diseases including multiple sclerosis, rheumatoid arthritis, Crohn’s disease and psoriasis. Dr Jenkins says: “Autoimmune diseases are complex, but there is no doubt that inflammation increases the risk of developing issues and can exacerbate problems. There are studies showing drinking tea, or taking tea extracts, reduces this risk in some conditions.”
And the paper adds: “Regular black tea intake reduced markers of inflammation such as CRP and appeared to aid immune regulation, possibly via gut microbiota change.”
Gut instincts
The lining of our gut appears to play an important role in many diseases, and this could help to explain many of the health benefits of tea drinking too. Dr Tim Bond explains: “Black tea polyphenols may help maintain a strong gut barrier and improve the gut’s bacterial balance, which may benefit people with inflammatory bowel conditions in particular.”
He adds: “The integrity of the gut lining, and the extent to which molecules can pass from the gut to the bloodstream, has body-wide implications for health, wellbeing and our risk of disease. Many age-related diseases have been linked to systemic inflammation and ‘leaky gut’, as this dysfunction of the gut barrier is known. Cardiovascular disease, type 2 diabetes, osteoporosis and dementia are just a few of older-age diseases that have been linked to ‘leaky gut’ and the types of bacteria which make up our gut microbiome.”
What’s brewing?
Whether it’s drunk with or without milk, black tea, is brimming with health-enhancing polyphenols, with average concentrations ahead of those found in some fruit and vegetables as well as orange, tomato, cranberry and apple juices. These polyphenols include anti-inflammatory theaflavins, catechins and flavanols as well as gallic acid – which the new paper points out “shows potential in terms of its ability to suppress pro-inflammatory responses and oxidative stress, often seen with conditions such as obesity”.
Dr Tim Bond explains how tea polyphenols can help defend against harmful molecules (Image: Courtesy Dr Tim Bond)
Black tea also contains useful amounts of the bioflavonoids quercetin and kaempferol which help dial down inflammation, while L-theanine, an amino acid found in high concentrations in black tea, has been found to inhibit oxidative damage. The new paper concludes: “Many of these constituents have demonstrated anti-inflammatory properties individually and synergistically. The combined action of these compounds may contribute to the modulation of inflammatory pathways and oxidative stress, offering potential benefits in the prevention or management of chronic diseases linked to inflammation.”
And Dr Jenkins adds: “What makes this evidence review valuable is it provides easy-to-action news you can use to help reduce your risk of low-level inflammation and the known health risks associated with this increasingly common health challenge. Unlike a lot of the health advice that GPs are asked to share with their patients, suggesting they drink three or four cups of tea a day is one tip I know they are likely to follow.”
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