DNA Methylation testing (and why I’m not as young as I think I am!) By: Amy-Killen I February 27, 20
I got my My DNAge Methylation test results back today and I gotta say, I’m not ecstatic. I’m happy enough with the test itself (really cool test!) but I’m disappointed in myself. I took the test when I was 43 years and 11 months old and the test showed that my “biological” age was 44. So, basically, my chronological age matches my biological age. BUT it also showed that I’m only in the 32nd percentile for youthfulness among people my age who have taken the test. This does not warm my heart.
As a physician who loves learning about longevity, having a DNA methylation age that pretty much matches my chronological age is like a stab in the heart. And the ego. How can this be? I exercise regularly. I’m not overweight. I sleep 8 hours a day. I don’t have a lot of stress (I even own several meditation apps!). And, I know a lot about health and aging. But, there’s the rub. KNOWING something and DOING something are two different things. I KNOW I need to eat gobs of vegetables every day, but sometimes I’ll go days without a green food in sight. I KNOW I should lay off the processed food, but the gas station attendant near my office may or may not know my name because I so often pop in for a protein bar, string cheese or some God-Awful meat stick when I don’t have time for an actual lunch. I don’t eat much sugar, but I still sometimes make poor beverage choices.
So, how do the choices I make on a daily basis affect my DNA and what exactly is a DNA Methylation test? DNA methylation is the best-studied epigenetic modification and is known to be a reliable indicator or biological age. Here’s how it works:
My DNA has never changed. It’s a series of base pairs in several long strings that I inherited from my parents and later passed down to my kids. My DNA sequence acts as the blueprint for my body – it’s a lovely drawing of how my body should look and perform over time. But, how I ultimately look, feel, act and age can change based on the choices I make everyday. What I put in my mouth, how much I exercise, where I live, how I think – all of these things can and do change how my DNA is expressed. The blueprint doesn’t change, but the way it’s read, or interpreted, can and does.
We recently remodeled our house. We had an architect come in and he jotted down his ideas for the house on paper. This blueprint was a bunch of lines and curves that laid out how one might rebuild a house. But, what if we did something to that blueprint that didn’t actually change the underlying drawing, but did change how it was interpreted by the general contractor? For example, what if we spit chewing gum onto the drawing so that the bathroom door now looks like a half-door? The general contractor wouldn’t know that the original drawing called for a full door so he would build a knee-high door to our bathroom. You can imagine that if this happened multiple times while the house was being remodeled then the way the house looks (phenotype) as well as how it stands the test of time (biological age) could both be affected. This is similar to DNA methylation.
Our environment, stress, and lifestyle choices can cause certain segments of DNA to become methylated over time. A methyl group (CH3) attaches to specific parts of the DNA and changes the way that segment is expressed. It’s like throwing a ball of chewing gum on an architectural plan. DNA Methylation tests can measure these epigenetic modifications to our DNA to make inferences about how quickly we’re aging.
Scott Horvath developed one of the most popular epigenetic clocks in 2013 after analyzing more than 8000 samples of DNA across 51 different cell and tissue types. Horvath showed that certain portions of the DNA sequence, known as CpG dinucleotides, were more likely to fall victim to an epigenetic change that adds a methyl group (CH3) to a cytosine base. He also revealed that this age-related methylation of CpG’s could be defined dependant of sex or tissue type. This means that a sample of saliva, urine or blood can all be used to map out and quantify DNA methylation and make educated guesses about biological age.
To make things even more complicated, methylation of DNA can correlate positively or negatively with aging, depending on the location of the group. For example, in certain sections of the DNA, aging and poor lifestyle results in an additional methyl group (similar to my chewing gum analogy). But, in other sections of DNA, aging and poor lifestyle choices may actually cause the deletion of a needed methyl group. Both types of changes have been accounted for in the most common DNA methylation epigenetic tests.
How fast your epigenetic clock is moving, also known as the “ticking rate” is partially out of your control. The genes themselves influence how quickly some of these methylation changes occur. BUT (and it’s a big “but”), lifestyle can also affect ticking rate. And, since we can’t
In future blog entries I’ll dive more into exactly what types of lifestyle changes affect epigenetics most, as well as some of the new discoveries in the land of anti-aging pharmaceuticals. But for now… I’ll go eat my vegetables like a good girl.
If you want to get your own My DNAge test, check out www.mydnage.com and use the promo code “Amy15” for 15% off your purchase.