This is an exchange on Drug Watch International with questions from Roger Morgan and responses from Dr Stuart Reece (in bold italics)

Hi Stuart

In reflecting on the studies referred to by Peggy Mann from 40 or 50 years ago, combined with your recent research, I believe we need to do some more research.  I have the following questions:

1. What is involved evaluating the chromosomes in cells of humans?  Do you take a chunk of flesh, or ???? No.  Would most universities have the capability to do this? No.

If you wanted to do this properly studies would involve the following.  I think they need to be detailed and extensive in view of the now massive populations risks which are presented.  You are actually talking about something which may be devastating – if 12% of Coloradan babies are impact PRIOR to legalization then “Houston, Houston we have a problem…  This is Apollo 13 calling.”

1. Cell culture studies – many cells, neurons, sperm and eggs, gut cells skin cells
2. Several species – white rabbit and hamsters model humans best.
3. Human cell lines – many
4. Human cells – skin cells, cheek cells, transformed white blood cells – lymphoblastoid cells – EBV infected lymphocytes taken from blood samples
5. Human sperm

1. A key change would be to apply next generation sequencing to these cells and tissues so:
   1. DNA
   2. RNA
   3. Proteins
   4. DNA methylation
   5. Histone changes – nuclear proteins looking for
   6. Epigenetic changes
   7. Epitranscriptomic changes
   8. Metabolome changes
   9. The interaction between the metabolome and the epigenome
   10. Profile the immune change including cytokines in detail – these are very important and far reaching and cause aging and germ cell damage – cytokines – TH17 cells etc…
   11. Compare the immune and growth factor changes seen in cannabis exposed patients with old folks and compare the way they reproduce clinical aging.

1. Look at pregnancies prospectively.  Look at the sperm of males – sequence them do genetic and epigenetic studies.  Then study their babies and see if they carry the same abnormalities after birth…  See how the correlate with the various congenital anomalies.

2)  What are the implications if the cannabis consumers only have half of the 46 chromosomes that are normal in humans?  Not true.  Physical and mental abnormalities in offspring …. and future generations?..   Chromosomal anomalies will do this yes – and chromosomal shattering processes which cannabis can induce.  Cannabis changes cell division process causing chromosomal shattering and also epigenetic changes – changes in the signalling along the DNA on how the genes are used and expressed.

3)  Will the chromosome levels return to normal if a person quits consuming cannabis?   Short answer – not studied yet.

Long answer – yes I think there will be a degree of repair.  However I also think it is unlikely ever to return to normal. Especially after heavy use because some of the epigenetic imprinting is permanent – obviously from studies which have been done.

4)  Cannabis is known to cause mutations to sperm and ova which can affect a fetus even before pregnancy.  If they stop using, will everything return to normal?  Same as above. Serious concerns.  Depends on level of exposure.  Depends on time between cannabis and making babies…   I do not mean to imply that one or two joints as a young person and babies ten years later is bad.  Nothing suggests that.  But heavy cannabis use such as we are seeing more and more if – and Deborah Hasin from Mailman School of Public Health  in 2017 said USA has an extra 500,000 of in legal states – that is a big problem for later reproduction.

I think the evidence that young people of reproductive age should not go near cannabis for genotoxic reasons is now very strong indeed, and so too do all of my collaborators including my biostatistical friends.

Consider:

1. 12.6% of Coloradan had major congenital anomalies in 2013 PRIOR to legalization
2. The rate of cannabis use by people over 12 years in Colorado was 14% in 2013
3. The rate of cannabis use by all pregnant women in California in 2015 was 8% on testing
4. The rate of cannabis use by mothers less than 20 years in California was 24% in 2015.

So about as many babies are being born deformed AS ARE BEING EXPOSED TO CANNABIS.

So clearly a very high percentage of cannabis exposed babies are experiencing major congenital anomalies.

This should send shivers down our spine – not only that cannabis use is rolling out but that cannabis use is aimed primarily at young adults the very group who should be keeping well away from it.

We need to define these risks much better at the population level by careful studies.

Sperm would be easy to collect and study and define and then correlate with subsequent foetal outcomes.

Thanks and God bless – and spare us all,

Stuart.

Source: Email to Drug Watch International www.drugwatch.org April 2018