Genetics. Can we sit back and blame our genes for our ills, lack of ability to lose weight or our addictions?

Posted by & filed under Health and Fitness.

This is taken from a film called Zeitgeist Moving Forward.  Its available free – click on the link to find out more. This part of the film is called It’s Genetic and the basic tenet is that is it only too easy to take a deterministic view of genes that makes us think things cannot be changed and it is not worth wasting time or resources in trying to fix root causes of genetic behaviours or diseases.  It is taken as an easy cop out to blame developing either type of diabetes, cancer, MS, becoming an alcoholic, for example, on our genes. Certainly we can have predispositions to these troubles, but how we lead our lives, the choices we make and our how we bring up our children means we can activate or deactivate genes. Yes, we can come from a family that is prone to excessive body fat – but if we learn how to eat for those genes, we do not have to become fat ourselves.  I have a client who is living proof of this.  He is nicely lean, but the rest of his family are not.  Amusingly, they think of him as anorexic.

Dr Gabor Maté1 gives an example using the breast cancer gene.  Out of 100 women with breast cancer, only 7 will be carrying the gene.  And out of 100 women with the gene, not all of them will go on to develop breast cancer.  He says that the search for diseases in the human genome is doomed to failure because most diseases are not genetically predetermined eg heart disease, cancer, strokes, rheumatoid arthritis, auto immune disorders mental health conditions, addictions.  The point is the difference between pre-determined and pre-disposition.  Pre-determined is inevitable.  To have a predisposition is only a small part of the whole story.

Until 7min 20 secs in, the video deals mainly deals with behaviour.  After that the emphasis shifts to addictions and that will appear in a different blog. The point the video is making is that genes have only a small part to play in behavioural problems.  Dr James Gilligan2 refers to a study done in New Zealand which followed a few thousand people from birth to their 20s and it was found that a genetic mutation could be identified in some which predisposed the individual to violence.  However, this gene only expressed itself if the child was subjected to severe child abuse.  If a child with this genetic mutation had a normal upbringing, the child actually had a lower rate of violence than people with normal genes3 .Furthermore not all children exposed to severe child abuse went on to become violent offenders.  Many went on to lead normal adult lives.

Robert Sapolsky4 cites the study done on mice which had the specific gene for learning and memory knocked out – and it was found that indeed the mice did not learn well5.  This was touted as a finding the genetic basis of intelligence.  What was less appreciated was taking those genetically impaired mice, raise them in a much more enriched and stimulating environment than normal mice in a lab cage and the mice completely overcame the deficit6 .  Which connects well to the blog on teaching the blind to see – the brain is far more plastic and adaptable than previously thought.  Genetics are not the be all and end all of intelligence or behaviour.

  1. Dr G Maté, physician, author, Portland Society []
  2. Dr J Gilligan, former director or the Center for the Study of Violence, Harvard Medical School []
  3. Click on the link to read a paper by Dean Madden of the National Centre for Biotechnology Education, Reading Univ.  This paper refers to this study and other studies that bear out its findings. []
  4. Dr R Sapolsky, Professor of Biological Sciences and Professor of Neurology and Neurological Sciences at Stanford University []
  5. Tsien J, Huerta P, Tonegawa S.   The Essential Role of Hippocampal CA1 NMDA receptor-dependant synaptic plasticity in spatial memory.  Cell, Vol 87, 1327-1338 Dec 1996 []
  6. Rampon C, Tang Y, Goodhouse J, Shimizy E, Kyin M and Tsien J.  Enrichment induces structural changes and recovery from nonspatial memory deficits in CA1NMDAR1-knockout mice. Nature Neuroscience 3 (2000):238. []

Leave a Reply

  • (will not be published)