By Eric Brand

The other day Bob alerted me to a very interesting article in a Chinese journal (Journal of Practical Traditional Chinese Internal Medicine, Nov. 2009, Vol. 23, No. 12). The article measured the content of various minerals, trace elements, and heavy metals in samples of Bei Wu Wei Zi (Schisandra chinensis).

...

The article was very interesting because it compared 8 different samples of Wu Wei Zi that were harvested in different regions in Northeastern China. Four growing regions in Liaoning and Jilin provinces were selected, and the seeds and the skin of the fruit were assayed independently. The study demonstrated that there is significant variation in the nutrient content of the specimens, as well as significant variation in their heavy metal content. Companies that produce Chinese herbal medicines need to test every batch of product that they produce because this natural variation can cause individual lots of herbs to be rejected during quality control screening, even among items that are not normally problematic.

A brief smattering of highlights from the data:

Overall, the seeds vary significantly from the skin of the fruit in terms of their heavy metal content and nutrient content. For example, there is often a four-fold difference in the amount of potassium found in the seed and the skin even when comparing the products from the same batch (the potassium content in the skin is much higher). By contrast, there is more magnesium in the seeds than there is in the fruit skin. Many specimens had twice the amount of magnesium in the seeds than they had in the skin, and significant variation was observed between growing regions. For example, one specimen had nearly 100 times more magnesium in the seeds that the seed specimen from a different growing region. A ten-fold difference in iron content was also found between individual specimens of the skin.

In terms of heavy metals, major differences could also be seen. For example, one specimen of the skin had more than 4-8 times the amount of arsenic that the other specimens contained. The same specimen also had 2-3 times the amount of lead that the other specimens contained, as well as 2-4 times the amount of cadmium. These variations underscore the importance of rigorous testing and quality control, because natural variations in the soil can have a major impact on the medicinal product.

At Blue Poppy, we have run hundreds or thousands of independent tests on our products over the years. We emphasize quality control when it comes to sourcing the raw materials, so we’ve encountered very few problems over the years and we have never accepted a batch that didn’t meet our standards. However, any company that makes extracts long enough will eventually encounter a batch or two that does not pass muster, so it is always important to test every product, every time. Blue Poppy is proud to be the only company in the TCM industry that uses independent third-party testing for every batch of every product that we produce, and the research paper that I read last night was just another reminder of how important this commitment is to our customers and their patients.