Health Benefits of Oolong Tea
Oolong tea is rich in antioxidants. It contains essential vitamins and minerals such as copper, calcium, carotin (carotene), selenium, manganese and potassium, as well as vitamin A, vitamin B, vitamin C, vitamin E and vitamin K. Oolong tea also contains folic acid, niacin amide and other detoxifying alkaloids. Oolong tea is developed by using a semi-fermented process that creates polyphenolic compounds by oxidising catechins in raw green tea leaves, contributing even more beneficial health properties to the tea. Oolong tea like all other teas contains caffeine, theophylline and theobromine (similar to caffeine) which stimulate nervous system when ingested.
Oolong tea is processed in a way that it retains the qualities of both green tea and black tea. It has all the polyphenols (anti-oxidants) such as catechins that are high in green tea and white tea but also the other polyphenols that are high in black tea (and pu’erh tea). The duration and type of processing of an oolong dictates the levels and ratio of catechins vs theaflavone/thearubigins.
The catechin polyphenols have the ability to deactivate (scavenge) the many environmental free radicals we breathe in and ingest however the black tea polyphenols (theaflavone/thearubigins) have a greater ability to limit the enzymes in our body that create free radicals during metabolic processes. Polyphenols also have the ability to up regulate the body’s own antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase, but also non-enzymatic counterparts such as glutathione, ascorbic acid, and α-tocopherol.
The different polyphenols all work in different ways at cellular level and the science is only in its early stages trying to understand the separate mechanisms, however the many scientific studies today do show broad observations and co-relationships between tea polyphenols, health and disease (1, 2).
Oolong Tea, Antioxidants and Harmful Free Radicals
A free radical is a molecule that damages tissue (skin and organ). We breathe free radicals in, we ingest free radicals (pollution, chemicals etc) and free radicals are also created as a by-product of our own metabolism. The trick is to keep these free radicals at a minimum to limit tissue damage, DNA damage and cellular turnover thus limit ageing – antioxidants help to reduces free radical damage.
Oolong tea possesses a range of different polyphenols/bioflavinoids (antioxidants )thus oolong tea has multiple functions to process free radicals and render them harmless. Oolong tea, unlike black tea, green tea or white tea, has high levels of myricetin, kaempferol and quercetin (antioxidants) (3, 4).
By limiting the free radicals and protecting against DNA tissue damage we lower our risk of such diseases as atherosclerosis, stroke, neurodegeneration, cancer, rheumatoid arthritis and diabetes (5)
Oolong Tea and Inflammation
Not only does Oolong tea posses antioxidant abilities, it also has anti-inflammatory properties that down regulate the bodies (gene-enzyme) inflammation pathways (6)
Oolong Tea, Weight Loss and Obesity
Like green tea and black tea oolong tea also contains caffeine, theophylline and theobromine which all up regulate thermogenesis (helps your body produce more heat) to increasing the body’s metabolism (the rate at which your body burns energy) (7).
Thearubigins and theaflavins are the most predominate polyphenols in oolong tea. They are not found in green tea and they are different from the Thearubigins and theaflavins found in fully fermented teas. Many studies have shown oolong tea to be effective in reducing weight and fighting obesity by inhibiting glucose or fat absorption.
Studies have shown that the special polyphenols in Ooolong tea reduce the pancreatic enzyme (glycosyltransferase and lipase) thus lipids (fat) stored as fat (8). Another study has shown that oolong tea helps the body burn fat faster (9)
Another study demonstrated that oolong tea consumption can reverse the function of an enzyme called a-amylase thus block the breakdown of carbohydrates, lower blood glucose level and also prevent the transfer of glucose into fats in adipose tissue (11)
Ultimately oolong tea can help reduce obesity by reducing fat and glucose absorption and also block fat creation, increasing metabolism/fat burning as well as reducing inflammation (which is also implicated in obesity) (12, 13, 14)
Oolong Tea and Cancer
Oolong tea is rich in anti-cancer properties. And drinking oolong tea helps to significantly lower risk of developing ovarian and pancreatic cancer (15, 16) . Oolong tea also seems to lower the risk of skin cancer (17). Considering that oolong tea shares similar properties of green tea then it could be assumed it will share the same risk reduction with regards to bowel, prostate, breast and stomach cancer, but so far studies have mixed results (18).
The exact mechanism is still unknown and in fact there could be a variety of different mechanisms where by oolong tea, green tea and black teas protect against cancer.
Although the cancer-tea research accumulated thus far is still not absolutely conclusive, the National Cancer Institute has now started to focus more upon the possible anti-cancer benefits of teas (19)
Oolong Tea, Healthy skin (Atopic Dermatitis and Contact Dermatitis)
There has been a Japanese study that found atopic eczema resolved in a 118 people after consuming oolong tea 3 times per day for 6 months. The effects were noticeable within a few weeks of participating in the study.
After 1 month skin lesions had reduced moderately in 74% of the people and after 6 months the eczema was still moderate in 54% of the study participants (20). This study showed that oolong tea was moderately effective in resolving atopic eczema.
Oolong Tea, Healthy Bones and Osteoporosis
Oolong tea contains antioxidants that seem to protect against osteoporosis by maintaining bone density. There have been many studies looking at the correlation between bone loss and tea consumption, some of these studies have been long term studies. Its assumed that oolong and black teas promote the retention of minerals from our diet. Most of these studies have been looking at black tea and some have been observing oolong tea. Considering that oolong tea shares a similar polyphenol profile then it can be assumed oolong tea has the same benefits or similar benefits to that of black tea (23,24)
Diabetes and Oolong Tea
Oolong tea has also shown varying levels of effectiveness with regards to reversing insulin resistance, lowering blood glucose and increasing glucose uptake in type 2 diabetes. Oolong tea seems to suppress the proteins that bind to insulin thus rendering insulin ineffective (25) therefore the dangerous highs and lows of blood glucose can be reduced by drinking oolong tea. Oolong tea may also guard against developing diabetes. Large scale human studies show a direct co-relationship between tea consumption and reduced diabetes (26)
Dementia and Cognitive functions
Green tea in general has been shown to improve cognitive functions such as mood, alertness, calmness, and contentedness, attentional switching accuracy even within the first 1-2 hours (27).
There has been a significant amount of research with regards to Alzheimer’s as well as cognitive function of the brain. A large population study (Singapore Longitudinal Ageing Study) showed that consumption of a daily cup of tea (green tea, oolong tea, black tea and pu’erh tea) for people over 55 years of age reduces cognitive decline by over 50% and people with a genetic predisposition to Alzheimer’s reduced their risk by 86% (31, 32, 33)
Golden Ocean Chinese Tea
Specialising in various kinds of Black tea, Green tea, White tea, Yellow tea, Oolong tea, Dark tea, Pu Erh Tea, Scented tea, Flowering tea, Herbal tea and Tea Powder, Tea ware, Tea pots, cups, mugs, Tea canisters, Tea containers. We supply the finest and rarest Chinese teas imported directly from China.
59A Campbell Parade, Manly Vale NSW 2093