Splitting hairs over inconclusive evidence of chromosome damage caused by excessive doses of cannabinoids may fuel some scientific careers, but conclusions resulting from such speculation are easily discounted. Test-tube methods of creating chromosome breaks with cannabinoids could be duplicated with aspirin, Valium, and many other pharmaceutical drugs. Moreover, DNA samplings of large populations of heavy users in cannabis-friendly countries have failed to show any abnormalities in chromosome structure.

Hollister states that, “virtually every drug that has ever been studied for dysmorphogenic effects [chromosome interference leading to birth defects] has been found to have them if the doses are high enough, if enough species are tested, or if treatment is prolonged.” [2]  Other scientists conclude that, “the few reports of teratogenicity in rodents and rabbits indicate that cannabinoids are, at most, weakly teratogenic in these species.”[3] According to the United Nations World Health Organization report of 1997, “There is not a great deal of evidence that cannabis use can produce chromosomal or genetic abnormalities in either parent which could be transmitted to the offspring.” [4]

Related sections: Cancer, Immune Responses.

[1] “The health and psychological consequences of cannabis use.” Chapter 6, National Drug Strategy Monograph No. 25, Australia

[2]  Hollister, “Health aspects of marijuana.” Pharmacological Review, Vol. 38, No. 1, 1986

[3] Bloch, et al., quoted in Hollister, op cit

[4] World Health Organization Project on Health Implications of Cannabis Use, 1997