There may be more to this than the old wives’ tale.
Your back page correspondent comes from a long and deeply devoted line of tea drinkers.
Such was my grandmother’s dedication to the sanctity of the tea ceremony, when her chimney caught fire one morning and the firemen rushed in to put out the blaze Gran insisted they all sit down to have a cup of tea before quenching operations commenced.
The fireys wisely prioritised the more immediate threat of charred demise, but the incident spoke volumes as to just how relaxed Grandma Reynolds’ default demeanour was.
Perhaps it was all the tea she drank? It transpires that’s not such a silly idea, according to a new study from the University of California.
Research recently published Cellular Physiology and Biochemistry has found compounds in both green and black tea relax blood vessels by activating ion channel proteins in the blood vessel wall.
The study, titled KCNQ5 potassium channel activation underlies vasodilation by tea, not only helps unravel the antihypertensive properties of tea, it could also help in the design of new blood pressure-lowering medications.
The key elements are two catechin-type flavonoid compounds, called epicatechin gallate and epigallocatechin-3-gallate, found in tea, which each activate a specific type of ion channel protein named KCNQ5, which allows potassium ions to diffuse out of cells to reduce cellular excitability and relax blood vessels.
Earlier studies have already shown that drinking tea can reduce blood pressure by a small but consistent amount, and that catechins are involved in this process. But it’s this latest identification of KCNQ5 as a novel target for the tea catechins which could help chemists improve potency or efficacy of hypertension drugs.
So with more than two billion cups of tea being drunk each day across the globe, we can only imagine how uptight the world would be if we all switched to coffee.
If you see something your gran would approve of, post it to felicity@medicalrepublic.com.au.
