It has been demonstrated through countless studies over the past decades that exercise is good for us.
It helps reduce risk factors for numerous disease states including heart disease, diabetes, hypertension, cancer, and osteoporosis among many others. The degree to which we know the exact mechanism of these effects is varied, but we have not known how deep this effect goes until quite recently.
A number of studies including those published in the journal Cell Metabolism in 2012 and in Medicine and Science in Exercise and Sport in 2009 have demonstrated that these positive changes go as deep as our DNA.
Epigenetics is defined as the way our DNA behaves and affects us. If you recall your high school or university chemistry classes, there are groups of atoms that make up methyl clusters and the behaviour of our genes can be affected by adding or subtracting these methyl groups on the outside of the genes.
In the 2012 study, researchers found that changes in methylation in genes responsible for cardiovascular health were positively affected by acute bouts of exercise.
Researchers have known for a while that similar methylation changes occurred for exposure to other lifestyle conditions such as diet and pollution, but this was the first real evidence that exercise has an effect as well.
In order to eliminate the effect of these other lifestyle variables, researchers had participants exercise one leg on a stationary bike and measure the methylation patterns in the exercised and non-exercised legs.
The epigenetic effect in this study however does not mean that exercise actually changes the DNA itself, just their behaviour in expressing themselves producing various proteins that affect our health. Scientists had generally thought that once the process of methylation had occurred, this in effect switched the gene on or off like a light switch. The study has shown however that exercise seems to be able to reverse that switch. It is important to note that these acute positive methylation changes were not permanent and regular exercise would be needed to maintain those changes.
The other study involving exercise and DNA has to do with immune cell telomere properties and longevity. At the end of chromosomes there are protective strands called telomeres. Every time a cell divides, these strands shorten slightly and as such are considered to be biomarkers of cell aging.
Researchers cited the fact that environmental stressors such as psychological, oxidative and socioeconomic factors all negatively affected telomere length and that another 2008 study had linked physical activity to telomere length as well.
The study involved the effect of exercise on 69 healthy men and women aged 50-70 and compared physical activity levels with telomere length in immune cells.
The results showed that the group who were involved in moderate levels of physical activity and exercise had the least reduction in telomere length compared to sedentary or highly active individuals.
The researchers concluded that this telomere effect may not be occurring for acute bouts of exercise but probably occurs over at least five years of consistent physical activity.
Another study in 2013 done at the University of California involving 35 men with prostate cancer also had similar telomere results when participants adopted healthy eating and exercise habits.
So the next time you are thinking about doing some exercise, think of how powerful a change you will be making to your body – right down to your very DNA.
Now that’s a motivator.
Kerry Senchyna is the founder, owner and president of West Coast Kinesiology and is a provincially registered kinesiologist.