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YOU ARE WHAT YOUR GRANDPARENTS ATE
The theory of epigenetics
Introduction
This is a chapter I wrote for my book, Trick and Treat: How 'healthy eating' is making us ill. But the book was getting too big and, in the end, I left it out. A year on, however, I regret that decision because there is evidence from a new scientific discipline called Epigenetics which strongly suggests that how we eat today could have a profound effect, not just on our health, but on future generations.
Here is that chapter.
Bizarre things are going on that we are just beginning to get a handle on
DR MARCUS PEMBREY
Scanning through scientific journals today shows that gene-based biology is at the centre of most research. This research, apart from trying to determine how our bodies are made, is fondly hoped to be the ultimate weapon in the medical world's fight against disease. Scientists across the world have been working for years on unravelling and learning to understand the human genome — Nature's blueprint for a human being. This, they believe, will allow them to manipulate the genes that make some people more susceptible to disease in such a way as to prevent that disease. They also hope to be able replace 'faulty' genes in people with an existing disease.
The diseases they hope to cure or prevent are largely the ones in this book: diseases and conditions that only 'took off' in the last century or so. But it is a simple fact of evolution that these diseases are not genetic — our genes do not mutate that quickly. These diseases are brought on us by the way we live and the way we eat.
According to the latest theories of heredity and evolution, the tremendous variation we see amongst living organisms comes about in one of two ways: either through spontaneous mutation or through chance hybridisation during sexual reproduction. It is chance variation which leads to a species changing in response to its environment so that those most fitted to any environment are more likely to survive. This is what is meant by 'survival of the fittest'. But these genetic changes only take place over many hundreds or thousands of generations; they don't happen in just three or four.
That at least is the accepted wisdom. But is it true?
The conventional view of evolution is that our DNA carries all our heritable information. It is made up of the genetic codes already encoded in the sperm and egg from which we are made. This means that it is already fixed when we are born, that nothing we do in our lifetime can alter it, and that we will pass on that genetic code, unaltered, to our children.
Now a new science is emerging that questions this paradigm.
Epigenetics
In the 1980s, evidence emerged which questioned the accepted view of inherited genes. What it suggested was that the lives of our grandparents — the air they breathed, the food they ate, even the things they saw and did — could affect not only them and their children, our parents, but also directly affect us, their grandchildren, decades later, despite our never experiencing these things for ourselves. And that in turn means that what we do in our lifetimes could also affect our descendents for generations to come. This new discovery has led to a new science called epigenetics.
To many scientists, epigenetics, by calling into question the accepted view of the DNA sequence which is a cornerstone on which all modern biology depends, amounts to heresy. So let's look at some of the evidence — and at the possible consequences of not considering it in the context of our current lifestyle.
There are several lines of evidence we can consider. We'll start in Part 2 with the effects of our diet.
Part 4: Cancer Clue | Part 5: Conclusion and References
Last updated 17 November 2009
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