Known for its immense popularity, Chinese tea has been studied for its role in so many health benefits from helping in weight control to thwarting diseases. Tea is one of the most popular drinks in Asia and has gradually gained its popularity globally. Let’s look at the plant behind “real” tea.
There are five main types of tea – green, black, white, Oolong and Pu’er or pu-erh – in Chinese tea. They all differ a bit in how they grow, how they are processed, and how they are oxidized. However, they all come from the same plant. Here is a general overview of some of their characteristics.
One important note: this is a story about what is considered “real” tea, not “herbal” teas. Because unlike real tea, brewed from a plant, herbal teas, are produced from a combination of different herbs (that’s time for another conversation.)
Camellia Sinensis Plant
White, green, black, oolong and Pu’er teas are made from the leaves of the same species, the Camellia sinensis plant. It is an evergreen shrub whose leaves and leaf buds are used to produce tea. It is from the genus Camellia of flowing plants in the family Theaceae.
Oxidation
The major factor that determines whether a tea plant will become white, green, oolong or black tea is oxidation. Oxidation refers to chemical reactions that result in the browning of tea leaves and the production of flavor and aroma compounds in finished teas, says the American Specialty Tea Alliance.
Tea producers use certain methods to prevent oxidation in order to have different flavors in a finished tea and then different types of teas.
Oxidation begins after the leaf has been plucked from a plant, then it is dried and rolled. For each kind of tea, oxidation occurs in different ways.
Black tea, for instance, is known as fully oxidize and that cause it to turn black, and has the most robust flavor. It is also known as honcha’ or literally red tea in Chinese.
White tea, on the other extreme, is hardly oxidized, which means it can retain its natural antioxidants, but is not as flavorful. The beverage is a pale yellow.
Green tea has a minimum amount of oxidation, too, and the result is its grassy, earthy, sweet feel and taste.
Pu’er tea is a variety of tea that has many flavors, more complex than the others. The town of Pu’er in China is named after the tea.
Oolong has a wide range of oxidation, and its range of colors is from dark green to black with an earthy smoky flavor.
Health Aids
When we think of cell damage in our body, much of it is related to oxidation of cells. Antioxidants help repair the damage. Green tea is listed as having many antioxidants and nutrients, with its range of health benefits, such as improving our thinking, controlling weight, and helping to fight cancer.
It includes the antioxidants known as epigallocatechin. A green tea molecule that breaks up atherosclerotic plaque and can help prevent heart attacks.
The health benefits of green tea for the heart has been known for some time. Research shows that flavonoids in green tea reduced the risk of cardiovascular disease, stroke, and conditions that are known to contribute to these diseases, such as LDL (bad) cholesterol, and blood pressure. New research, however, singles out how a specific green tea molecule and plaque protein interaction could lead to new medicines to prevent heart attacks and stroke.
Green Tea and Epigallocatechin
Epigallocatechin-3-gallate (EGCG) is a green tea polyphenol (plant phytochemical). It is already known as the source for many of green tea health benefits. For example, researchers at Leeds University and Lancaster University in Great Britain found EGCG reduced amyloid, a type of protein in plaque associated with Alzheimer’s disease. These same researchers wanted to see if EGCG had a direct effect on plague in arteries that cause heart attacks and stroke.
Amyloid and Apolipoprotein
Amyloid plaque in the arteries has deposits of the protein apolipoprotein (apoA-1). Interestingly, amyloid apoA-1 deposits are similar to the ones involved with Alzheimer’s disease. In late-stage hardening of the arteries, apoA-1 builds within the plaque. The apolipoproteins buildup causes the plaque on the artery walls to enlarge which then restricts blood flow. Also, the apoA-1 proteins can make plaque unstable. Unstable plaque can dislodge from the artery walls and create blood clots or lead to a heart attack.
Caffeine
The lack of oxidants is responsible for the low caffeine content of green tea, which is known as perfect for meditation or overcome nervousness and insomnia. Oolong tea has more caffeine than green tea. White tea releases the least among of caffeine of all teas.
Among all the teas, black tea, which is among the most popular, has the most among of caffeine. It is generally stronger in flavor than the less oxidized teas.
References:
- Berkeley Wellness. Tea Benefits A Research Wrap-Up. Retrieved from https://www.berkeleywellness.com/healthy-eating/food/article/tea-benefits-research-wrap
- Howlett G.J., Moor, K. J. Untangling the role of amyloid in atherosclerosis (October 17, 2006). Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/16960503
- Mitchell, Jennifer. Green tea molecule could prevent heart attacks (May 31, 2018). Retrieved from https://www.sciencedaily.com/releases/2018/05/180531190840.htm
- Nordqvist, Joseph. What to know about atherosclerosis (December 13, 2017). Retrieved from https://www.medicalnewstoday.com/articles/247837.php
- Rambaran, Roma N., Serpell, Louise C. Amyloid fibrils. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2634529/
- Townsend, David, et al. Epigallocatechin-3-gallate remodels apolipoprotein A-I amyloid fibrils into soluble oligomers in the presence of heparin (January 23, 2018). Retrieved from http://www.jbc.org/content/293/33/12877