Teens who prefer alcohol to marijuana are more likely to have reduced brain tissue whereas those who choose to smoke over drink show no abnormalities. The rumor that smoking weed kills your brain cells is taking a major hit with this experiment on brain scans. The researchers scanned the brains of 92 teenagers over 18 months, and at the end of the experiment found no difference in brain health for participants who smoked nine times a week on average. The brain health for the young drinkers though showed significant damage. Hit the jump for more. PaulDaPro