Hold clinical trials before concluding cordyceps' effects

Two reports have described cordyceps as having blood-thinning effects ("Cordyceps 'likely led to post-op bleeding'"; May 27, and "How safe is herbal medicine?"; June 14).

But the active ingredient in cordyceps - adenosine - is a building block of adenosine triphosphate (ATP) - an energy molecule in our body. Adenosine can be synthesised by our body to form ATP and adenosine diphosphate. Once consumed, ATP is broken down to adenosine and others, or further decomposed; it is a metabolic cycle happening every minute.

Therefore, adenosine exists in our body all the time. If serious blood thinning can be caused by the presence of adenosine, shouldn't the human body be genetically vulnerable to even a small cut on the skin? Adenosine is widely found in nature, including in foods as well.

Second, when adenosine is used as a drug, it is mainly delivered through intravenous means, while cordyceps, as a herbal medicine, is orally administrated.

The drug delivery channel is significant because orally ingested molecules will be subject to the destructive forces in our digestive tract and have to travel a long way to meet the target, such as a platelet.

Third, adenosine is generally considered to be a neuromodulator and is believed to play a role in promoting sleep and suppressing arousal. It also has a role in the regulation of blood flow to various organs through vasodilation (widening of blood vessels), but not very often regarded as a blood thinner, at least not as a mainstream indication.

Finally, there are no medical reports suggesting that cordyceps is clinically able to thin blood.

It is very easy for an institution to prove this with a clinical trial. But until then, we shouldn't be talking about something without clinical evidence, while using ambiguous terms such as "likely" or "possible".

Mark Xu Yue