Time for coffee and tea
Black tea and heart disease
The following sections of time for coffee and tea take a look into a research paper by Gardner et al, that looks into the health implications of drinking black tea.
Black tea is consumed by around three quarters of the British population. It is known to have many important influences upon health; these include positive ones such as a reduction in the risk of coronary heart disease and cancers, and negative ones, which are mainly thought to be as a result of the caffeine content of the product. Research by Gardner et al has taken a look at all of the literature available on the consumption of black tea and seven areas of health.
The following is a small break down on their findings on the most common cause of death in Britain, coronary heart disease.
There have been many reports that have linked the consumption of tea with a reduction in death by coronary heart disease. Of the many reports on the subjects not all could be used as they also tested the effect of flavonoids additional to those found in black teas, or tested only specific areas of coronary heart disease such as risk factors or testing diets.
After eliminating all the research that did not meet their strict criteria Gardner and colleagues were able to make use of 21 studies that had some type of link (good, bad or indifferent) between drinking black tea and coronary heart disease.
The analysis of Epidemiological research papers suggested that the consumption of three cups of tea day (about a pint; and the quantity that is averagely consumed in the UK) could cut the risk of coronary heart disease by about 11%. Though there were some epidemiological papers that did not support the findings of this link between black tea consumption and the risk of coronary heart disease it was thought that these papers did not take into account key factors such as smoking, weight and the low social status of the people surveyed.
It is thought that the link between drinking three cups of black tea a day and a reduction in the risk of coronary heart disease is likely to be real because there is a biochemical explanation of the phenomenon. Polyphenols found in black tea are very strong antioxidants. The type of antioxidants that are found in black tea, flavonoids, have been shown to stop the oxidation of LDL cholesterol. Additionally, it has been demonstrated that black tea flavonoids are able to both improve coronary vasodilation and reduce clots.
Other components that are found in black tea are also likely to be involved in the positive health links between drinking black tea and the reduction in the risk of heart disease, for example manganese may reduce the risk of coronary heart disease by influencing cardiac muscle function.
Black tea and health part three: cancer
References