In time everything we do to treat injuries, prevent disease, or reverse disease will eventually change. Think of all the things we used to do in medicine. Cocaine was used for toothaches. In the 1600’s, “hydrotherapy” was used to would wash away insanity in mental patients. Jan Baptist van Helmont would literally drown people to death and then resuscitate, believing that water would cleanse and the near drowning would snap people back to reality. In the 1800’s ketchup was used to treat athletes foot. In rehabilitation science, we use a myriad of techniques that we think is proper today, but overtime, the way we treat will drastically change and I believe it will come sooner rather than later.
Simply stated, epigenetics is the process by which we alter how genes respond, without altering DNA structure. Epi means above or around. So, epigenetics is above or around the gene. Everything we do has a genetic consequence. The foods we eat or the exercise we perform can turn genes on or off, can reduce or enhance their signaling output, or alter what they do. This occurs through a process called DNA methylation.
DNA methylation is a process where a methyl group (CH3) is added to a nucleotide (see below). DNA methylation may stably alter the expression of genes in cells as they differentiate from embryonic stem cells into specific tissues. See my articles on mechanotransduction, why ice does not work, and treatment of Achilles that describes cellular signaling further.
When we do things consistently, we change the way our genes respond, which causes an effect. Smoking does not directly cause lung cancer. Smoking causes changes in our genes that lead to cancer. Cardiovascular exercise does not directly improve our ability to run longer. It alters our genes so that our cells are better at utilizing oxygen, which results in increased endurance.
Epigentics of physical exercise
Cancer is nothing more than epigenetic mutations in cancer cells that cause the cell to grow and divide uncontrollably. Physical exercise has been shown to reduce and even reverse these epigenetic mutations, increasing expression levels of tumor-suppressing genes and decreasing expression levels of oncogenes. (1)
The effects of aging result from a loss of DNA methylation over time. In one study, adult individuals who obtained thirty or more minutes of exercise a day had significantly more DNA methylation as compared to sedentary individuals (2).
A friend of mine shared an article on Facebook that was really fascinating. The article discusses how exercise created changes in muscle, through epigenetics. Here is a quote from that article:
“The volunteers pedaled one-legged at a moderate pace for 45 minutes, four times per week for three months. Then the scientists repeated the muscle biopsies and other tests with each volunteer.
Not surprisingly, the volunteers’ exercised leg was more powerful now than the other, showing that the exercise had resulted in physical improvements.
But the changes within the muscle cells’ DNA were more intriguing. Using sophisticated genomic analysis, the researchers determined that more than 5,000 sites on the genome of muscle cells from the exercised leg now featured new methylation patterns. Some showed more methyl groups; some fewer. But the changes were significant and not found in the unexercised leg.
Interestingly, many of the methylation changes were on portions of the genome known as enhancers that can amplify the expression of proteins by genes. And gene expression was noticeably increased or changed in thousands of the muscle-cell genes that the researchers studied.
Most of the genes in question are known to play a role in energy metabolism, insulin response and inflammation within muscles. In other words, they affect how healthy and fit our muscles — and bodies — become.”
While having drinks with a friend one day, she mentioned that her dad is a nutrageneticist in Switzerland. I had no idea what a nutrageneticist did, so I researched. This is what actually prompted the research and writing of this blog. This new field of study, nutrigenetics, is finding that DNA structure can change with diet.
Nutragenomics is the study of the effects of foods and food constituents on gene expression. Diet influences how genes react and as a result, different diets will elicit different patterns of gene and protein expression and metabolite production. Today, geneticists examine the DNA of individuals with chronic disease and seek to treat with a specifically formulated diet that will influence the way genes operate and allow for homeostasis in cells. So, if a person suffers from a certain disease that is consistent with a specific genotype, we can provide a diet that is specifically designed to alter that genotype and reverse that disease.
How can you not be fascinated by this? Science and medicine is changing before our eyes. I believe that in a decade—or two, or three—the rehabilitation programs we provide will be designed to alter our genetic transcription. Instead of increasing muscle strength, enhancing proprioception, or helping collagen align, maybe our therapeutic programs will be guided by the gene we want transcribed. Instead of doctors injecting corticosteroids and anti-inflammatories, maybe we will have geneticists attempting to alter a patient’s genetic code. Instead of relying on heavy doses of medication, perhaps a nutrageneticist will provide diet plans to reverse diseases like alzheimer’s, MS, or cancer.
- Handy, D. E.; Castro, R.; Loscalzo, J. Genetics Primer for the General Cardiologist. Circulation 123. 2011. (467): 2145–2156.
- Zhang, F. F.; Cardarelli R; Carroll J; Zhang S; Fulda KG; Gonzalez K; Vishwanatha JK; Morabia A; Santella RM. Physical activity and global genomic DNA methylation in a cancer-free population. Epigenetics. March, 2011. 6 (3): 293–9.