Sir

Both your Editorial 'Hard to swallow' and your News Feature 'A culture in the balance' on traditional Chinese medicine (Nature 448, 106 and 126–128; 2007) focused on herbal remedies. However, although herbal formulations make up the bulk of traditional Chinese medicine, many animal-based remedies are also used.

These often expensive remedies are increasingly sought after in China, and although only a small proportion of the tissue used comes from endangered species such as rhinoceroses and tigers, the demand is having destructive effects on many organisms. In particular, populations of many turtle and tortoise species, both in China and around the world, are declining rapidly as they are captured in the wild and their shells ground into a jelly that is thought to cure diseases such as cancer.

The ecological effects of the use of wild-caught animal tissues as part of traditional Chinese medicine are an important issue that must be part of any discussion of its merits and disadvantages.