This is the second post in the series of epigenetics. If you are new, start here
Last time we learned what epigenetics is and how it changes our gene expression. We looked at how histone modifications occur that make some part of our gene unreadable to the cell thus turning the gene on or off.
As described in the book Epigenetics Revolution by Nessa Carey, Imagine the human lifespan as a long movie.
In this movie, cells would be the actors and actresses — essential units in the movie. DNA would be the script — that instructs actors and actresses what they need to do. A block of DNA would be the actions in the script. Genetics would be the screenplay and the whole movie would be directed by epigenetics.
The interesting thing is that the epigenetic marks actually stick to the sperm DNA and the egg DNA and are passed on to the next generation or even the generation after that.
In a study done on mice, some male mice were fed a high fat, inflammatory diet (full of oil and sugars). The mice became obese, insulin-resistant and eventually developed type 2 diabetes. Now, these male mice had female offsprings that were fed a normal diet. They did not become obese but still developed type 1 diabetes. Why?
It turns out that, the high-fat diet caused an epigenetic mark called the Methyl Group (Me) to go and sit on the top of the sperm DNA near the gene which is responsible for creating insulin in the pancreas. This sperm DNA then created a new mouse that had the insulin creating gene turned off because of the epigenetic mark. The mouse eventually developed type 1 diabetes since it could not produce insulin.
In another study done on humans, scientists collected sperm DNA from age-matched obese and lean men. The sperm DNA collected from the obese men showed a large number of epigenetic markers that the sperm DNA from lean men did not have. In fact, they found that over 9000 genes were different between the two. These obese men then underwent a bariatric surgery making them lose tons of weight. Scientists again collected the sperm samples of these men a week later and a year later after the surgery. What they found was that the epigenetic marks on the sperm DNA had changed significantly. In fact, after a week, over 1500 genes had changed to show similarity with genes of the lean men and after a year over 3000 genes had these epigenetic marks completely removed.
Epigenetics is everywhere! The environment around us shapes our health.
It is now widely known that our genetic code carries traces of past events, meaning that trauma, poor diet or poor lifestyle choices, financial status, drug abuse, disease exposure, can leave a beneficial or harmful legacy for our children and grandchildren.
This means your genes are not just your destiny but they are also the destiny of your future generations. To conclude, you have this opportunity to literally change how your children develops, which brings us to the question - How do you plan to live your life?
Sources, related readings, and videos:
Research article in detail explaining epigentics
Research paper on paternal obesity and effects
Great video on epigenetics by Nessa Carey — a nice place to start on epigenetics
Joe Rogan podcast with Dr. Rhonda Patrick
Diet Gene Interactions by Dr. Rhonda Patrick