The Effects of Temporary Blood Sugar Elevation Can Cause Persisting Epigenetic Changes

Bad Eating Habits Can Alter Your DNA, a Yahoo health article, begins with this ominous remark:

Eating a single chocolate bar might cause harmful genetic changes or mutations that could have serious effects on your DNA, changes that could last for up to a couple of weeks.

While this may be true the original study was a bit more subtle than this.

The referenced research paper is Transient high glucose causes persistent epigenetic changes and altered gene expression during subsequent normoglycemia which appeared in The Journal of Experimental Medicine (Vol. 205, No. 10, 2409-2417). The paper was authored by Assam El-Osta, Daniella Brasacchio, Dachun Yao, Alessandro Pocai, Peter L. Jones, Robert G. Roeder, Mark E. Cooper, and Michael Brownlee and was published in the September 29, 2008 edition. Research efforts were made with reference to diabetes. The authors had this to say about diabetes:

Diabetes is a leading cause of blindness, end-stage renal failure, and peripheral neuropathy in most developed countries. Hyperglycemia-induced reactive oxygen species (ROS) initiate the complex series of molecular events that result in diabetic tissue damage, and transgenic expression of superoxide dismutase prevents diabetic complications in animal models.

They wrote about showing that transient hyperglycemia (a temporary elevation of glucose) induced epigenetic changes which persisted when blood sugar levels returned to normal. The epigenetic changes alter gene expression. The technical details are extensive and available by reading the paper but the bottom line for those concerned about health is revealed by this quote:

In summary, the observations reported here show that transient hyperglycemia causes persistent atherogenic effects during subsequent normoglycemia by inducing long-lasting changes in chromatin remodeling, recruitment of the histone methyltransferase Set7, and increased H3K4 monomethylation in the proximal NF-{kappa}B promoter, leading to increased expression of p65, MCP-1, and VCAM-1.

The genetic changes caused by temporary elevated levels of blood sugar can lead to the build up of plaque in arteries even after blood sugar levels have returned to normal. The reason for that is that although the blood sugar levels may now be normal the genetic changes induced when they were high persist.