With aging, our skin and other tissues (arteries and organs - heart, lungs, joints etc.) lose elasticity. In animals we can see clearly that the skin and muscle of old animals are stiffer that the tissues of the young ones.
However, if sugar levels are high, these sugars will affix to the protein uncontrollably forming AGEs (advanced glycation end-products). These AGEs will in turn bind to each other with the help of more sugar from the blood, forming a solid tissue of proteins and sugars. Stiffness of the tissues is the manifestation of high levels of AGEs.
Diabetics have a higher concentration of AGEs in their bodies. Their skin usually appears older: "diabetes can be thought of as a form of accelerated aging." Therefore, whatever dietary pattern leads to diabetes, will also lead to premature aging.
We already know that the consumption of a diet high in refined carbohydrate and sugar causes diabetes. It means, that these dietary elements will also lead to aging.
"Current evidence points to glucose, not only as the body's main short-term energy source, but also the long term fuel of diabetes complications."
- (American Diabetes Association)
We are all on the curve of aging and chronic diseases. These mechanisms are the same in all of us, even in healthy individuals. The extent of damage differs!
These syndromes are (from mild to more severe, and usually appearing together with time):
- metabolic syndrome
- heart disease
Yes, AGEs play a direct role in the development of heart disease: by stiffening the arteries, and by the oxydation of LDL particles (bad cholesterol) which will end up trapped in the artery lining, causing high blood pressure, leading to heart disease.
Again, whatever factors lead to high AGEs levels, will also lead to a higher risk of contracting heart disease.
"Anything that raises blood sugar [...] will lead to more atherosclerosis and heart disease, more vascular disorder, and an accelerated pace of physical degeneration, even in those of us who never become diabetic."________________________________
- Gary Taubes
Reference: Gary Taubes, Good Calories, Bad Calories