So I know that Chinese herbs are all the rage these days as some people are turning to alternative medicines. Here is a little something to be aware of: aristolochic acid.
Here is the backstory,
Balkan Endemic Nephropathy (BEN) was first described in the 1950s affecting areas of the Bosnia, Bulgaria, Croatia, Romania, and Serbia that were in close proximity to the Danube river. BEN is a chronic kidney disease that progressed to renal failure and is associated with transitional cell carcinoma of the bladder.
So what the hell was causing it? Believe it or not it was a native plant, Aristolochia clematitis, that got into the wheat fields. Bread being a major staple in the daily life of these Eastern European villagers, they would harvest their wheat and Aristolochia. Since these weren't exactly the 1%, they had primitive milling machines so while they were milling the grain, they also milled the Aristolochia seeds into the mixture as well. Well it turns out the aristolochic acid in the seeds could survive the milling and baking process.
How does aristolochic acid give you cancer? Easy after being digested and metabolized the aristolochic acid reacts with DNA to for aristolactam adducts with deoxyadenine or deoxyguanine (your DNA). After extensive research the adducts can exist for indefinitely in the tissue and evade detection of conventional repair mechanisms.
So what if you don't repair the adduct? The adduct is mutagenic, the aristolactam adduct causes A:T --> T:A base transversions in the DNA, commonly seen in p53, a tumor suppressor gene. When you loose functional p53, you are in what the first President Bush would call, deep doodoo. Also this lesion, can regularly escape repair based upon the strand selectivity of transcription-coupled nucleotide excision repair.
Okay okay, so how does this relate to Chinese herbs? Aristolochia, is a very common ingredient in many Chinese herbal remedies. So you've got to do your homework and check out the natural "safer" alternative medicine.
We know that China has an elevated rate of urothelial cancers, is it related to Chinese herb usage, particularly those containing aristolochic acid? Who knows but it deserves some further study.
Grollman AP, PNAS, 2007
Cosyns JP, Kidney Intl, 1994
Nortier JL, NEJM, 2000