A recent study published in BMC medicine analyzed the contents of over-the-counter herbal supplements from dozens of manufacturers. The results were anything but natural. More than half of the supplements contained plants not listed on the label and one third did not even contain the ingredient advertised on the bottle.

A prior literature review in 2001 found that various “natural” Chinese herbal medicines contained lead, arsenic, mercury, and copper. These heavy metals can cause neuropathy, mood changes, and toxicity in the central nervous system.

These studies show how important it is to find out all of the medications and supplements an individual is on when trying to determine the cause of their distress. It’s possible that an individual who you are deposing may think he or she has cognitive problems from an injury, but such symptoms can be explained, at least in part, by natural supplements.

You can find the article from BMC Medicine here:

http://www.biomedcentral.com/content/pdf/1741-7015-11-222.pdf)#sthash.52nz73Nn.dpuf

The citation for the Chinese natural supplements article is:

Ernst E and Coon JT. Heavy metals in traditional Chinese medicines: A systematic review. Clin Pharmacol Ther 2001 Dec; 70:497-504.