The Mechanisms Behind The Positive Effects Of Tea

Direct effect on blood vessels and heart

The short- and long-term consumption of black tea leads to the increase of catechin concentration in blood. This is associated with improvements in the heart function among patients with coronary arterial disease. In particular, biologically active components of tea improve the functions of the endothelium – the tissues lining the blood vessels.

Endothelial dysfunction is linked to atherosclerosis and other cardiovascular diseases. It is associated with increased oxidative stress. Antioxidants can at least partially reverse this stress. The flavonoids found in tea tend to accumulate in endothelial tissues during long-term consumption and help in this process.

Improvement of glucose metabolism

Another mechanism associated with the positive effect of tea on cardiovascular health deals with an improvement in glucose metabolism. Tea exerts its action on glucose metabolism via inhibiting the enzyme called amylase. Amylase breaks down starch with the formation of glucose. The inhibition of amylase slows down this process, thus minimizing the rise of glucose level in blood.

Drinking tea helps in the slower release and intestinal absorption of glucose which, in turn, prevents the dangerous rise of the level of insulin. Insulin is a key hormone in regulating the metabolism of sugars and fats in human body. Insulin is involved in the development of obesity and it accelerates the aging processes in the body. Glucose intolerance increases with age and leads to various degenerative disorders including atherosclerosis. The down-regulation of glucose level helps in avoiding these problems. The regular consumption of tea leads to calorie restriction and has a positive effect on life expectancy.

Reduction of cholesterol level

A reduction of cholesterol levels helps to prevent obesity, improves liver and heart health, and protects the pancreas. A high level of blood cholesterol is directly linked to a higher risk of myocardial infarction. Green tea drinkers have a healthier level of “good” cholesterol. Scientific studies point out that the components of green tea block absorption of cholesterol in the intestine, as well as help body to excrete cholesterol.

Elimination of free radicals

All types of tea are rich in antioxidants. The positive effect of antioxidants on health in general and cardiovascular health in particular is well documented. Antioxidants exert their positive effects via combating the reactive oxygen species, and primarily various free radicals. Free radicals are formed in the normal process of metabolism inside the cells.

A cell has multiple mechanisms of eliminating them, but under certain circumstances the self-protecting capability of the cell can be overstretched. An unhealthy diet and smoking contribute to the increased level of reactive oxygen species, which is associated with various health problems and accelerated rate of aging. Free radicals can attack and damage the membrane on the surface of the cell. This damage contributes to the development of various cardiovascular diseases. Antioxidants are capable of catching and chemically neutralizing the radicals thus contributing to protection of cell membranes.

Some studies demonstrated that antioxidants from green tea are six times more efficient than those from black tea. Green tea’s catechin outperforms vitamin C by as much as 10 times in neutralizing the radicals.

It is often not known exactly which compounds are responsible for the protective effects of tea. Although many active compounds have been identified with known biological effects, tea contains many unidentified components with potential biological activity.

Current medical advice

Most researchers are positive in their conclusions about benefits of tea drinking and recommend at least a moderate consumption of this drink on a regular basis. Although many details still need to be investigated, the general positive effect of tea is now well proven scientifically. Green tea is richer with catechins and seems to produce more significant long term positive effects. It should be mentioned, however, that in 2006 the US Foods and Drug Administration (FDA) rejected the petition of tea makers who asked to allow them to write on the green tea packages that the drink reduces the chances of heart diseases.

FDA argued that the existing scientific data are insufficient, inconclusive, and therefore there are no credible evidences to support this claim. The mounting evidences coming from more recent research might eventually force FDA to reconsider its recommendation. Many individual components originating from tea are already approved by various national health authorities as beneficial health supplement and complimentary medicines for managing various health conditions and disorders.