Tag Archives: holistic

How Safe Is Traditional Chinese Medicine?

13 Apr

The following is written by Kai Kupferschmidt of sciencemag.org:

Dangers of Chinese Medicine Brought to Light by DNA Studies

Traditional Chinese medicine (TCM) is enjoying increasing popularity all over the world. But two molecular genetics studies published this week show that the trendy treatments can be harmful, as well. The papers focus attention on the fact that not all of their ingredients are listed, or even legal, and that some can cause cancer.

“These two studies show very clearly how dangerous the products of TCM can be,” says Fritz Sörgel, the head of the Institute for Biomedical and Pharmaceutical Research in Nuremberg, Germany, who was not involved in the work. “The public needs to be better informed about these dangers.”

Hundreds of millions of dollars are spent on TCM products each year—a growing portion of it on the Internet—and some scientists are looking at these preparations hoping to discover new pharmacological substances. Many would like to emulate the success of Tu Youyou, the Chinese scientist who isolated artemisinin, now the world’s most important malaria drug, from an ancient Chinese medicine. Tu won a Lasker award last year and is rumored to be a Nobel candidate.

But critics have long warned that some mixtures can also contain naturally occurring toxins, contaminants like heavy metals, added substances such as steroids that make them appear more effective, and traces of animals that are endangered and trade-restricted.

Now, researchers at Murdoch University in Australia have investigated the problem using modern sequencing technology. The team, based at the university’s Australian Wildlife Forensic Services and Ancient DNA Laboratory in Perth, analyzed 15 samples of traditional Chinese medicine seized by Australian border officials.

“We took these traditional preparations, smashed them to pieces, and extracted the DNA from the powder,” explains molecular geneticist Michael Bunce. The scientists then fished out copies of two specific genes, trnL, a chloroplast gene common to all plants, and 16srRNA, conserved among plants and animals, and multiplied and sequenced them. By comparing the sequences to those in genetic databases, they could pinpoint the animals and plants used to make the medicine. “Sometimes we really struggled to assign a particular DNA to a particular species,” Bunce says. But as genetic databases expand, this should become easier.

Some products contained material from animals classified as vulnerable or critically endangered, such as the Asiatic black bear and the Saiga antelope—just as the producers claimed. But often, the medicine also harbored ingredients not mentioned on the packaging, the team reports online today in PLoS Genetics. “For example, a product labeled 100 percent Saiga antelope contained considerable quantities of goat and sheep DNA,” Bunce writes.

“Using DNA to identify the animal species and thus prove illegal trading is very elegant,” says Dietmar Lieckfeldt, who works in molecular forensics at the Leibniz Institute for Zoo and Wildlife Research in Berlin, Germany. Identifying animals by their DNA has been possible for a while, he says, but the next-generation sequencing technology makes it possible to nail different species in a mixture very quickly.

In the herbal preparations, Bunce and his colleagues found members of 68 different plant families, among them plants of the genera Ephedra and Asarum. Both can contain toxic chemicals such as aristolochic acid, a compound banned in many countries because it causes kidney disease and cancer of the upper urinary tract (UUC). While detecting DNA from a certain species does not mean that a toxin produced by that plant is present, chemical analysis of one of the four samples containing Asarum DNA did turn up aristolochic acid.

The threat posed by aristolochic acid is also highlighted in a paper published in the Proceedings of the National Academy of Sciences on Monday. The researchers, led by pharmacologist Arthur Grollman of Stony Brook University, focused on Taiwan, the country with the highest rate of UUC in the world. A previous analysis had shown that roughly one-third of the Taiwanese population consumed herbs likely to contain aristolochic acid.

The scientists sequenced the tumors of 151 patients with UUC. Among patients with characteristic mutations in the important tumor-suppressor gene TP53—which make people more vulnerable to cancer—84% also showed a known molecular signature of exposure to aristolochic acid, they found. The study provides compelling evidence that aristolochic acid is a primary cause of UUC in Taiwan, the authors argue.

Bunce and his colleagues also found DNA from plant families known to contain medicinally important species that could pose risks when used in combination with other drugs, as well as DNA from soybean and plants of the cashew family, which can contain allergens. “This just shows that the ingredients in these preparations aren’t accurately declared,” Bunce argues. Indeed, says Sörgel, the studies show that partaking in traditional Chinese herbal medicine is a gamble: “We just don’t know enough about it.”

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Black Tea = Happy Heart

14 Mar

Black Tea Is Shown To Lower Blood Pressure


Western Australian tea drinkers are helping build evidence that black tea may aid in maintaining cardiovascular health — with local researchers showing three cups of black tea daily lowers blood pressure by 2 to 3mmHg.

Lead author Jonathon Hodgson from the University of Western Australia’s School of Medicine and Pharmacology says many studies have looked at black and green tea in relation to heart and vascular disease outcomes.

“Meta-analyses of these studies indicate that drinking more tea, compared to drinking less or no tea, is associated with about a 10 to 20 per cent lower risk of heart disease and stroke,” Prof Hodgson says.

Seeking to investigate if this association was causal, the team from UWA and researchers from Unilever, conducted the first human intervention study to look at black tea and blood pressure outcomes.

“There have been a number of human intervention studies looking at effects on vascular function, with reasonably consistent findings that tea can increase the relaxation of blood vessels — an outcome linked with blood pressure and risk of heart disease,” he says. “This was the first large study specifically designed and powered to look at blood pressure as the primary outcome.”

Ninety-five Australian participants aged between 35 and 75 were required to drink three cups of black tea or three cups of a placebo, with the same flavour and caffeine content as the tea, daily for six months. Using 24-hour blood pressure measurement taken at the end of the trial, the group found a reduction in the systolic and diastolic blood pressure of the tea-drinkers of between 2 and 3mmHg.


According to Prof Hodgson, while a reduction of 2 or 3mmHg is not large, it is still a valuable effect when combined with other interventions.

“If you put the effect of tea together with other dietary and lifestyle changes, such as weight loss or reduced salt and alcohol intake, you might get up to a 10mmHg reduction in blood pressure without drug therapy,” he says.

The group believe high flavonoid levels in black tea cause an increase in nitric oxide, a compound that acts on cells in blood vessel walls to cause relaxation, blood vessel dilation and, ultimately, a reduction in blood pressure. According to Prof Hodgson, the findings also show promise for those who prefer to not drink tea.

“You can get the same benefits if you eat enough of other flavonoid-rich foods such as apples, plums and red grapes — no tea required.”

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Quite a bit of research has been done over the years demonstrating the benefits of tea. So if the mood strikes you today, here is a handy dandy tea brewing chart. Drink tea and enjoy a happy heart ^_^