Can Green, Black or White Tea Cause Kidney Problems?

[muie]

I was watching the nightly news from my country in Eastern Europe and this report came on which said that Green Tea or Black Tea (as well as White Tea) can cause kidney problems such as kidney stones, especially in people who have problems with thier kidneys.

I would like to know more on this issue as my father suffers from kidney problems. I know from Wikepedia that Green/Black/White teas increase circulation through the kidneys.

Also other teas such as Red Bush (Red Tea/Rooibos), which is another powerful anti-oxidant which lacks the xanthines that the Camellia Sinensis plants do.

However Green tea and White tea are very helpful so I hear for problems involving edemas and I don't know of many other herbal alternatives for treating edemas.

Any input on this situation would be gladly welcomed!

 

[nuke]

It's controversial. While tea (and coffee) contains high amount of oxalic acid which commonly makes up a high percentage of the composition of kidney stones, many studies have actually shown that one of the active compounds in green tea also actually prevents stone formation.

Effects of green tea on urinary stone formation: an in vivo and in vitro study.

Jeong BC, Kim BS, Kim JI, Kim HH.
Department of Urology, Seoul National University College of Medicine and Clinical Research Institute, Seoul National University Hospital, Seoul, Korea.
PURPOSE: We evaluated whether epigallocatechin gallate (EGCG), a main constituent of green tea polyphenols, could protect against cellular toxicity by oxalate and whether green tea supplementation attenuates the development of nephrolithiasis in an animal model. MATERIALS AND METHODS: Cells of the NRK-52E line were incubated with different concentrations of oxalate with and without EGCG, and toxicity and malondialdehyde assays were done to investigate the cytotoxic effect of oxalate and the anti-oxalate effect of EGCG.. In a second series of experiments, male Sprague-Dawley rats were divided into three groups. Group 1 animals (controls) were fed regular chow and drank water ad libitum; group 2 animals were fed chow containing 3% sodium oxalate with the administration of gentamicin (40 mg/kg) and drank water ad libitum; group 3 animals were fed the same diet as group 2 with gentamicin administration and drank only green tea. Rats were killed 4 weeks later after a 24-hour urine collection, and the kidneys were removed for morphologic examination. RESULTS: As oxalate concentrations increased, the number of surviving cells decreased, and the formation of free radicals increased. The administration of EGCG inhibited free-radical production induced by oxalate. Green tea supplementation decreased the excretion of urinary oxalate and the activities of urinary gammaglutamyltranspeptidase and N-acetylglucosaminidase. The number of crystals within kidneys in group 3 was significantly lower than in group 2. CONCLUSIONS: Green tea has an inhibitory effect on urinary stone formation, and the antioxidative action of EGCG is considered to be involved.

Preventive effects of green tea on renal stone formation and the role of oxidative stress in nephrolithiasis.

Itoh Y, Yasui T, Okada A, Tozawa K, Hayashi Y, Kohri K.
Department of Surgical Medicine, Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya City, Aichi 467-8601, Japan. [email protected]
PURPOSE: Urinary stones are similar to arteriosclerosis in epidemiology, mechanism, calcification composition and age at frequent occurrence. The calcification that occurs in arteriosclerosis is inhibited by antioxidants. Green tea leaves contain approximately 13% catechins, which have been shown to have antioxidant effects. We investigated the inhibitory, antioxidative effects of green tea on calcium urinary stone formation. MATERIALS AND METHODS: A total of 120 Wistar rats were divided into 4 groups, namely group 1-control rats receiving saline, group 2-stone group rats administered ethylene glycol (EG) and vitamin D3, group 3-drink group rats administered EG, vitamin D3 and green tea given as drinking water, and group 4-powder group rats administered EG, vitamin D3 and 2.5% powdered green tea leaves mixed in a powder diet. Pooled 24-hour urine samples and blood samples were collected and the 2 kidneys were excised 7, 14 and 21 days after administration, respectively. One kidney was used for immunohistological examination of osteopontin, superoxide dismutase (SOD), p65, p53 and bcl-2 expression, in situ hybridization of osteopontin and detection of apoptosis, while the other was used for quantitative analysis of SOD activity. RESULTS: Green tea treatment decreased urinary oxalate excretion and calcium oxalate deposit formation. Green tea treatment increased SOD activity compared with the stone group. The degree of apoptosis in the stone group was significantly increased compared with the drink and powder groups. CONCLUSIONS: The inhibitory effect of green tea on calcium oxalate urolithiasis is most likely due to antioxidative effects.

I've been drinking 3-6 cups of green daily for the past 5 years and haven't had any kidney problems.

 

[thujone]

not to mention the japanese who have been drinking it daily for like, ever. remember when the newspapers were saying WINE IS GOOD FOR HEALTH? they forgot to mention that grape juice is even better for health since it doesn't contain that toxic thing... umm.. shit what's it called... arggg i can think of this.... oh right, alcohol!

of course, communism would sweep over eastern europe again before anyone there dares to admit alcohol is unhealthy

 

[LivingInTheMoment]

Aparantly there is controversy! Some links below may assist you.
There are a number of foodstuff that contain oxalic acid, and just avoid eathing them in combination for a long time.
If you drink tea, but use lemon, that cleanses and it works well with it!
Flushing your system with lots of water, but mostly with self made lemonade with fresh lemons assists flushing your urinary track.

PS Who is to say, that it is tea that caused kidney stones in the people who went through the research, of one urologist-and not being hereditary or other problems, such as people not hydrating their system enough?

Some of the links are offering assistance in cleansing stones (???if advanced i don't see how)

http://kidney.niddk.nih.gov/kudiseases/pubs/stonesadults/index.htm



http://www.thirdage.com/kidney-disease/does-tea-contribute-to-kidney-stones

http://www.healthnews.com/family-he...ting-iced-tea-may-limit-kidney-stones-men-181

http://www.newswise.com/articles/view/542808/



http://www.amazing-green-tea.com/green-tea-and-kidney-stones.html



http://curezone.com/cleanse/kidney/default.asp

http://www.healthgoods.com/education/health_information/General_Health/update_kidney_stones.htm