The legalization of marijuana in Colorado for recreational use has some people totally freaked out. One implicit assumption seems to be that if it was illegal for so long, it must be really bad for you. Certainly it must be worse than alcohol, which has been legal nationwide since 1933. But is that true? The editorial board of the New York Times doesn't think so, claiming, "Of the two substances, alcohol is far more hazardous." So let's go to the tale of the (medical) tape and see each substance's effect on our health.
According to a study by Boston's Beth Israel Deaconess Medical Center and Harvard Medical School, smoking marijuana increases the risk of having a heart attack five times (!) within the first hour of smoking. Within hour two, the risk declines considerably, and by hour three, the risk is back to normal.
Alcohol is a different story. Depending on the user, it can either be heart-healthy or quite dangerous. Those who have any number of heart conditions enjoy special heart risks associated with alcohol consumption. But for others, moderate alcohol consumption has benefits, including increased HDL (good cholesterol) and decreased blood pressure.
Here's where marijuana use gets ugly. According to WebMD, "Long-term use of marijuana can make lung problems worse. Regular, long-term marijuana use has been associated with several cases of an unusual type of emphysema, a lung disease." Presumably, these problems are associated with smoking marijuana rather than eating it.
Perhaps surprisingly, alcohol is also quite dangerous to the lungs. It can cause alcoholic lung disease. However, it's worth noting that according to one study, "The association between alcohol abuse and acute lung injury remains largely unrecognized, even by lung researchers."
Marijuana has no known effect on the liver. Alcohol, on the other hand, can single-handedly destroy your liver. Liver-related risks of alcohol consumption include fatty liver disease, which usually shows no symptoms; alcoholic hepatitis, which affects up to 35% of heavy drinkers; and alcoholic cirrhosis, the effects of which cannot be reversed.
Short-term marijuana use has no serious impact on the brain. Long-term use, on the other hand, has been linked to impaired thinking, memory problems, and psychological issues including anxiety.
The effects of alcohol consumption on the brain are almost too many to mention. For starters, alcohol inhibits thought processes, which makes it difficult to think clearly. It also acts on the medulla, which induces sleepiness.
Alcohol also affects the kidneys. High blood pressure is the No. 2 cause of kidney failure, and alcohol consumption is known to raise blood pressure. Meanwhile, there is no known effect of marijuana on the kidneys.