Black Tea & Health
This area of the website covers a variety of health related information about black tea.
Did you know?
Approximately 40% of the nation's fluid intake today will be tea
Tea without milk has no calories. Using semi-skimmed milk adds around 13 calories per cup, but you also benefit from valuable minerals and calcium.
Four cups of tea with milk provides 21% of daily calcium requirement.
Tea is a source of the minerals manganese, essential for bone growth and body development, and potassium, vital for maintaining body fluid levels.
The average cup of tea contains less than half the level of caffeine than coffee. One cup contains only 50mg per 190ml cup.
Tea is a natural source of fluoride and drinking four cups makes a significant contribution to your daily intake. (Only 11% of UK water supply has fluoride added.)
Green and black teas are from the same plant, Camelia sinensis, and contain similar amounts of antioxidants and caffeine.
Tea in all its forms remains one of Britain’s favourite drinks. While we enjoy it, it is also great news for our wellbeing and there is emerging evidence that shows that a cup of tea is packed with potentially helpful benefits. Dr Tim Bond a tea health scientist and a member of the Tea Advisory panel (TAP) shares some of this emerging evidence:
Diabetes – a growing number of studies have shown that people who drink three to four cups of black tea per day could have a lower risk to type 2 diabetes than those who drink between zero and two cups per day. The effect of tea may be due to the variety of compounds present in tea, including the flavonoid antioxidants found in tea. However, more evidence is now needed to understand how and why.
Recent studies have also looked at the effect of black tea consumption on post-prandial blood glucose and insulin response following sugar consumption in normal and pre-diabetic subjects. In summary, the resulting data revealed that black tea consumption may improve blood glucose control following a meal. This may be due to black tea’s major bioactive compounds, the polyphenols.
Hydration– contrary to popular belief tea is not dehydrating. In fact, it is an important source of fluid and both the Food Standards Agency and British Dietetic Association advise that drinking tea can help to meet daily fluid requirements (8 cups of fluid a day).
Alertness – A number of emerging studies have shown that ingredient compounds found in black tea, such as L-theanine and caffeine may improve our attention span. Tea has been associated with many mental health benefits such as improved mental attention, clarity of mind and relaxation and further research is needed to understand the exact mechanisms as to why.
Ageing and cognitive function - Emerging research suggests a benefit of tea in ageing and mental function. Studies indicate that the impact of tea, likely due to its content of polyphenols, could have a beneficial effect on cognitive function following stroke and be beneficial in ageing.
In addition, a study, which involved black tea, study subjects were supplemented with black tea to evaluate the impact of supplementation on the balance of oxidation or redox balance in the body. Redox status was evaluated at three stages of the subjects when they were young, middle aged and old. Black tea augmented redox status at all stages of the subject’s lives, an effect likely due to the presence of catechins in black tea. This finding could have positive implications for ageing but further clinical research is needed.
Butacnum A, Chongsuwat R, Bumrungpert A. Black
tea consumption improves postprandial glycemic control in normal and pre-diabetic subjects: a randomized, double-blind, placebo-controlled
crossover study. Asia Pacific journal of clinical nutrition 2017;26(1):59-64.
Kim Y, Keogh JB, Clifton PM. Polyphenols and
Glycemic Control. Nutrients 2016;8(1).
Bryan J. Psychological effects of dietary components of tea: caffeine and L-theanine. Nutr Rev 2008; 66:82–90.
Altermann CD et al. Brain Res Bull. 2017 Mar 19;131:78-84. doi: 10.1016/j.brainresbull.2017.03.007.
Redox (short for reduction–oxidation reaction) is a chemical reaction in which the oxidation states of atoms are changed. Any such reaction involves both a reduction process and a complementary oxidation process, two key concepts involved with electron transfer processes. Redox reactions include all chemical reactions in which atoms have their oxidation state changed; in general, redox reactions involve the transfer of electrons between chemical species. The chemicalspecies from which the electron is stripped is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced.