"A chemical found in marijuana known as tetrahydrocannabinol or THC has been found to potentially slow the process in which mental decline can occur in up to  percent of HIV patients says a new Michigan State University study.    Its believed that cognitive function decreases in many of those with HIV partly due to chronic inflammation that occurs in the brain said Norbert Kaminski lead author of the study now published in the journal AIDS. This happens because the immune system is constantly being stimulated to fight off disease.    Kaminski and his coauthor Mike Rizzo a graduate student in toxicology discovered that the compounds in marijuana were able to act as antiinflammatory agents reducing the number of inflammatory white blood cells called monocytes and decreasing the proteins they release in the body.    This decrease of cells could slow down or maybe even stop the inflammatory process potentially helping patients maintain their cognitive function longer Rizzo said.    The two researchers took blood samples from  HIV patients who reported whether or not they used marijuana. Then they isolated the white blood cells from each donor and studied inflammatory cell levels and the effect marijuana had on the cells.    The patients who didnt smoke marijuana had a very high level of inflammatory cells compared to those who did use Kaminski said. In fact those who used marijuana had levels pretty close to a healthy person not infected with HIV.    Kaminski director of MSUs Institute for Integrative Toxicology has studied the effects of marijuana on the immune system since . His lab was the first to identify the proteins that can bind marijuana compounds on the surface of immune cells. Up until then it was unclear how these compounds also known as cannabinoids affected the immune system.    HIV which stands for human immunodeficiency virus infects and can destroy or change the functions of immune cells that defend the body. With antiretroviral therapy  a standard form of treatment that includes a cocktail of drugs to ward off the virus  these cells have a better chance of staying intact.    Yet even with this therapy certain white blood cells can still be overly stimulated and eventually become inflammatory.    Well continue investigating these cells and how they interact and cause inflammation specifically in the brain Rizzo said. What we learn from this could also have implications to other brainrelated diseases like Alzheimers and Parkinsons since the same inflammatory cells have been found to be involved.    Knowing more about this interaction could ultimately lead to new therapeutic agents that could help HIV patients specifically maintain their mental function.    It might not be people smoking marijuana Kaminski said. It might be people taking a pill that has some of the key compounds found in the marijuana plant that could help.        Michigan State University has been working to advance the common good in uncommon ways for more than  years. One of the top research universities in the world MSU focuses its vast resources on creating solutions to some of the worlds most pressing challenges while providing lifechanging opportunities to a diverse and inclusive academic community through more than  programs of study in  degreegranting colleges."