There may be more health benefits to your morning cuppa than first thought, explains Rod Tucker
According to legend, in 2737BC, while Chinese emperor Shen Nung sat waiting for his servant to boil water, leaves from the Camellia sinensis tree blew into the water and created the first cup of tea. While this is likely to be an apocryphal tale, over the following centuries, the consumption of tea became commonplace across Asia, especially in China and Japan. It was introduced to the UK in the middle of the 17th century by Thomas Garway, who, even in those early days, declared that tea was a healthy beverage.
Today, tea is still reported as being the most popular beverage in the UK and there are a myriad of purported health benefits that have been attributed to its ingredients, catechin, L-theanine and caffeine. Tea comes in different forms depending on the way in which the leaves are fermented and can be either green, black, white or oolong.
The Camellia sinensis leaves are high in antioxidant flavonoids with the main compounds termed catechins, of which there are several including epicatechin and epigallocatechin and it is this collection of antioxidants that are thought to be responsible for the health properties of tea. Reported benefits include a reduction in stress, cognitive decline and risk of cardiovascular disease. This latter effect has been attributed to the fact that drinking green tea (or consuming its extracts) leads to a reduction in both total and LDL cholesterol.
Furthermore, studies in mice even suggest green tea extracts can prevent the ultraviolet light-induced premature skin aging. Black tea is also healthy and the compound, theaflavin (present in black tea) has been shown to possess anti-inflammatory properties.
But does the combined effect of these properties increase longevity? One study in elderly Chinese people (those aged 80 and over) suggested that daily tea consumption conferred a 10% lower risk of dying and while researchers did not collect information on which type of tea was drunk, in another study, coffee, green, black and oolong tea all provided a mortality benefit.
The most recent study to examine the effect of tea consumption on cardiovascular disease and all-cause mortality was published in the January issue of the European Journal of preventative cardiology. The study included over 100,000 Chinese adults who were followed for nearly seven-and-a-half-years. Participants were categorised as habitual tea drinkers (those who drank tea more than three times a week) and never or non-habitual drinkers if they consumed tea less than three times a week.
The results showed that compared to never or non-habitual tea drinkers, there was a 15% reduction in all-cause mortality for habitual tea drinkers. The study also found that tea drinkers had a reduced risk for atherosclerotic cardiovascular disease events compared to non-habitual or never tea drinkers. These results suggest that the mortality benefits are accrued from drinking tea just three times a week although translating these benefits into years, the authors reported that habitual tea drinkers aged at least 50 can expect to live for 1.26 years longer than their non-tea drinking peers.
But before pharmacists rush off and start telling patients to put the kettle on, how generalisable are these findings to the UK? Firstly, 49% of participants reported drinking green tea, whereas only 8% drank black tea, which is more commonly consumed in the UK. Secondly, tea drinkers in the UK often add milk and it has been suggested that this abolishes the absorption of flavonoids. In fact, in a recent study, the beneficial effects of black tea on blood pressure were lost when milk was added.
Although pharmacists don’t routinely promote tea drinking as a preventative lifestyle modification, it seems that regular consumption confers several health benefits which shouldn’t be ignored. Perhaps as pharmacists, we should advocate tea drinking to our patients and while for some, the prospect of no added milk (or even sugar) might seem unpalatable, this appears to be the most effective way to achieve the health benefits.