Only just found this out looking for info,
(easier to read maybe at link)
SAFER - Marijuana vs. Alcohol
"Alcohol use damages the brain. Marijuana use does not. Despite the myths we've heard throughout our lives about marijuana killing brain cells, it turns out that a growing number of studies seem to indicate that marijuana actually has neuroprotective properties. This means that it works to protect brain cells from harm. For example, one recent study found that teens who used marijuana as well as alcohol suffered significantly less damage to the white matter in their brains. Of course, what is beyond question is that alcohol damages brain cells."
* Alcohol use is linked to cancer. Marijuana use is not. Alcohol use is associated with a wide variety of cancers, including cancers of the esophagus, stomach, colon, lungs, pancreas, liver and prostate. Marijuana use has not been conclusively associated with any form of cancer. In fact, one study recently contradicted the long-time government claim that marijuana use is associated with head and neck cancers. It found that marijuana use actually reduced the likelihood of head and neck cancers. If you are concerned about marijuana being associated with lung cancer, you may be interested in the results of the largest case-controlled study ever conducted to investigate the respiratory effects of marijuana smoking and cigarette smoking. Released in 2006, the study, conducted by Dr. Donald Tashkin at the University of California at Los Angeles, found that marijuana smoking was not associated with an increased risk of developing lung cancer. Surprisingly, the researchers found that people who smoked marijuana actually had lower incidences of cancer compared to non-users of the drug.
* Alcohol is more addictive than marijuana. Addiction researchers have consistently reported that marijuana is far less addictive than alcohol based on a number of factors. In particular, alcohol use can result in significant and potentially fatal physical withdrawal, whereas marijuana has not been found to produce any symptoms of physical withdrawal. Those who use alcohol are also much more likely to develop dependence and build tolerance.
* Alcohol use increases the risk of injury to the consumer. Marijuana use does not. Many people who have consumed alcohol or know others who have consumed alcohol would not be surprised to hear that it greatly increases the risk of serious injury. Research published this year in the journal Alcoholism: Clinical & Experimental Research, found that 36 percent of hospitalized assaults and 21 percent of all injuries are attributable to alcohol use by the injured person. Meanwhile, the American Journal of Emergency Medicine reported that lifetime use of marijuana is rarely associated with emergency room visits. According to the British Advisory Council on the Misuse of Drugs, this is because: "Cannabis differs from alcohol … in one major respect. It does not seem to increase risk-taking behavior. This means that cannabis rarely contributes to violence either to others or to oneself, whereas alcohol use is a major factor in deliberate self-harm, domestic accidents and violence." Interestingly enough, some research has even shown that marijuana use has been associated with a decreased risk of injury."
