So far all the studies involving shiitake mushrooms have used extracts – usually either lentin or lentinan. Studies using the whole mushroom regarding HIV have not be conducted. Most studies have been laboratory studies and did not test the effects of the extracts in people. The few studies that have tested the effects on people with HIV/AIDS were small scale phase I/II trials. This means that the studies were testing whether or not the extracts were safe, and seeing if the extracts might be helpful against HIV/AIDS. The studies are not considered conclusive because not enough people took part to know if everyone would benefit the way the study participants did.
The studies using shiitake mushrooms have found several promising results. The phase I/II trials of lentinan established that it is safe to take, found no dangerous side effect, and that the side effects which did occur stopped almost immediately after treatment ended. The people given lentinan showed an increase in CD4 counts, in one study the CD4 counts went up an average of 142 CD4 cells/mm3 after taking lentinan and ddl together for one year. Participants who took only ddl showed a decrease on CD4 counts.
Studies of lentin have all be laboratory based, so there is no knowledge of how it will effect people. However, lab studies have found determined that lentin interferes with the process of reverse transcriptase, and important step in HIV replication. Antiviral medications classed as NRTIs and NNRTIs treat HIV by interfering with this process. If lentin is safe and effective in the human body, than it may have significant benefits in fighting HIV.
As promising as these studies are, it is unfortunate that none have been conducted using the whole mushroom. As chemicals extracted from shiitake, lentin and lentinan would both be classified as drugs and cannot be used to treat HIV until they finish going through the FDA approval process. Shiitake may provide the same benefits when taken whole or may not. Also, there is no knowledge as to what an effective dosage of whole shiitake mushrooms might be.
Shiitake are popular as food, and grown in several parts of the world. They can also be expensive to take over a long period of time. Luckily, it is possible to grow shiitake mushrooms in your home without much difficulty, and it is cheaper to grow them yourself than buy them if you intend to take them consistently. If you decide to start taking shiitake mushrooms or an extract from them, make sure you speak with your doctor so he or she can be alert for possible side effects and drug interactions. You might also speak with an herbalist or doctor of Chinese medicine about the best dosages to try.