Lower global DNA methylation levels have been associated with genomic instability and cancer in humans, making it a great potential biomarker in peripheral blood. So scientists took a close look at the factors around global methylation levels and found that race and gender play a huge role.
Researchers from Texas and New York measured the global DNA methylation levels in cancer-free individuals by pyrosequencing LINE-1s in peripheral blood, while at the same time tracking environmental and lifestyle factors like diet and body composition. When they determined what factors were associated with reduced LINE-1 methylation, this is what they found:
- Significantly lower global methylation levels in women
- Non-Hispanic blacks and Hispanics had significantly lower levels than non-Hispanic whites
- There were no significant changes with age, diet, or lifestyle
- When the confounding factors of gender and ethnicity were taken into account, no significant difference was found based on amount of body fat
So while bad exercise habits and a fast-food diet may give you high cholesterol and pants that are too tight, it doesn’t seem to influence your global DNA methylation levels. Instead, that seems to have much more to do with your sex and ethnicity.
The authors conclude that before global methylation levels in peripheral blood can become the next hot biomarker, the gender and race factors will definitely need to be accounted for.
Check on all the global methylation factors in Epigenetics, May 2011