Glycation

Most people are aware that oxidation caused by free radicals in the body and on the skin accelerate the aging process.  Antioxidants such as Vitamins A, C, and E are common actives used in cosmeceuticals to help fight free radical damage.  However, research conducted on key aging factors shows that protein glycation, in addition to oxidation, plays a prominent role in the aging process on the skin as well as within the body.  Glycation not only increases the incidence of free radical damage, but also, it causes certain age-related diseases as well as brown spots and premature wrinkling of the skin.

WHAT IS GLYCATION?

Simply put, glycation occurs when proteins, such as collagen and elastin, cross-link with sugar molecules (glucose or fructose) without the controlled action of an enzyme.  This non-enzymatic process, catalyzed in the presence of heat, is also known as the Maillard reaction and is responsible for the browning of overcooked foods.  Likewise, brown spots on the skin and on internal organs are good indicators of glycation accumulation.  Recent studies show that brown spots (also known as age spots) are the first warning signs of dementia progression.

Over time, the sugar molecule bound to the glycated protein is chemically modified, forming molecular structures called Advanced Glycation End-products (AGEs).  AGEs formation is irreversible and is harmful to the body because it changes the structure of the protein so that the protein can no longer perform its function.  AGEs also increases free radical production by 50 times compared to unglycated proteins.

As AGEs build up over time, they reduce the flexibility, elasticity, and functionality of the protein, inducing a myriad of degenerative diseases such as cataracts, retinopathy, osteoporosis, and Alzheimer’s disease.

On the skin, AGEs perpetuates apoptosis, or cell death, and increases the death rate of fibroblasts.  While apoptosis is a natural phenomenon that rids the body of damaged and dying cells, AGEs can accelerate cell death and kill healthy proteins.  Therefore, glycation compromises the structure of the skin by preventing collagen and elastin proteins from functioning properly, and then damaging the intracellular matrix that forms the structure of the skin.  These two processes contribute to the deterioration of collagen, thinning of the skin, and production of wrinkles and loss of skin tone.

In addition, glycation stimulates the inflammatory cytokins-IL-6, TNFα, making the skin appear rough, blemished, and inflamed.

HOW TO ADDRESS GLYCATION


While no conclusive report is available on actives that prevent or repair damage caused by glycation, several studies suggest that certain ingredients such as carnosine and aminoguanidine may inhibit glycation by entering in and preventing the course of the Maillaird reaction.

According to Dr. Peter Pugliese, carnosine, a di-peptide antioxidant that mimics the structure of Vitamin E, seems to prevent the protein and sugar molecules from entering into the Maillard reaction.  By bonding with proteins and carbonylated molecules, carnosine inhibits the potential cross-linking of glycated materials.  Carnosine also protects healthy proteins from being damaged by AGEs.

Aminoguanidine is another active that is reported to minimize glycation by inhibiting the formation and cross-linking of AGEs.  Clinical studies show that aminoguanidine slows the progression of certain diseases such as diabetic kidney disease.

Although glycation inhibitors are still being researched, active measures can be taken to slow and reduce the negative effects of glycation.  First, because glycation is perpetuated by heat, wearing sunscreen, limiting the amount of direct contact with UV rays, and avoiding eating food cooked at high temperatures can help fight the effects of glycation.  Also, cutting down the sugar in your diet limits the glucose or fructose that can bind to proteins and reduces the cross-linking that leads to AGEs.  Finally, supplementing your diet with carnosine and using skincare products containing carnosine and aminoguanidine will help reduce the effects of glycation in your body.

SESHA SKIN THERAPY offers the protection of carnosine in its Elixir Day Repair and in the new CLINICAL Protect/Repair – 30 Day Emulsion.  The CLINICAL line also features Advanced Antioxidant Cream with the dual benefits of carnosine and aminoguanidine.

Reference: Dean W, South J. Preventing AGEs and cross-linkages: a comprehensive approach. Vit Res News 2004, 18(10):1, 4-7, 13-14. 39.