Stopping the Glycation Process
by Annette Tobia, PhD and Alice Marcy, PhD
It may only take a few minutes of brisk walking to work off the calories from the extra teaspoon of sugar in your morning coffee, but the damaging effects of sugar on skin can persist for a much longer time. Our bodies use sugars as the nutrient source for energy and for maintaining cellular health. But sugar has a dark side: It can combine with proteins, fats or even DNA through a chemical reaction called glycation. In skin, sugar molecules can bind to proteins such as collagen and then eventually form advanced glycation end products–appropriately termed AGEs–through further oxidative chemical reactions. These AGEs can abnormally crosslink collagen molecules, making them less flexible and ultimately contributing to the appearance of prematurely aged skin. AGEs also act as inflammatory cellular signals and cause the release of inflammatory cytokines that lead to the production of matrix metalloprotease enzymes (MMPs) that break down collagen. If all of this isn’t bad enough, AGEs inactivate the body’s natural anti-oxidant repair system making skin even more susceptible to their damaging effects.
Glycation is ultimately a critical contributor to skin aging because skin collagen is replaced relatively slowly. It takes about 15 years to replace half of the collagen in skin, and collagen synthesis declines with age¹. These conditions cause damaged collagen to accumulate as we get older, leading to wrinkles and a loss of suppleness. Furthermore, UV-exposed skin has increased levels of AGEs², possibly due to the AGEs-promoting oxidative stress environment created from sun exposure.
Glycation-Fighting Cosmetic Ingredients
Cosmetic ingredients that fight glycation are generally from two groups. The first contains molecules that prevent sugars from attacking skin proteins or even reverse the process. Often these ingredients act as decoys for sugar molecules that are targeting collagen. Meglumine is one such ingredient, along with aminoguanidine, arg-lys peptide, carnosine (and the variant Alistin), Glyterra and Vilastene. Anti-oxidants make up the second group of anti-glycation agents; they can prevent the oxidative reactions that form AGEs. Meglumine also belongs to this second group, along with Vitamin C, vitamin E, and alpha lipoic acid, all of which are excellent antioxidants and are available in a wide variety of products. Botanical extracts such as those from green tea, gooseberry, grapeseed, blueberry, and cranberry are full of polyphenols that have antioxidant activity, and may also prevent the initial reaction of sugar with collagen. To be optimally effective, an anti-glycation cosmetic would have both types of ingredients. Lastly, use of sunscreen and protective sunglasses will minimize the glycation enhancing effects of UV rays.
Spa Treatments: Do They Work for Glycated Skin?
Glycation-damaged skin has impaired healing properties, so it is important to avoid harsh treatments that would result in extensive inflammation. Estheticians may prefer to use gentle skin treatments that support the formation of new collagen and elastin, and to aid cellular turnover in glycation damaged skin. Combining Meglumine with these treatments will enhance the healing and recovery process. Retinol use at night will spur collagen and elastin production, and decrease levels of collagen-degrading enzymes, while avoiding the challenge of UV sensitivity. Begin your skin-treatment protocol with products that have the lowest level of retinol and apply every other day. Then, work up to more frequent applications with a more concentrated product. Glycated skin may benefit from non-ablative microdermabrasion, laser resurfacing and light peels to address decreased cellular turnover. However, these may not be suitable for clients with thin skin. Anti-aging facials are beneficial to glycated skin because they utilize professional grade ingredients to stimulate collagen and elastin production and introduce precise ingredient combinations that are tailored to the client’s needs and skin type.
Glycation, Nutrition and Lifestyle
Although it is impossible to remove sugar from your diet, healthy choices that minimize ingestion of added sugar will also reduce the opportunities for glycation to occur. Sugar is often added during food processing to enhance the flavor, appearance or texture of the final product. Food labels can be deceptive. There are over 50 forms of added sugar, including corn syrup, galactose, dextrose, maltose, lactose and honey. Sugar may not be the leading ingredient in a food label list, but when all the versions of sweetener are added together, it can be a significant percentage. Carbohydrates in foods such as pasta, bread, rice and potatoes need to be considered as sugar sources too, since these are broken down during digestion to become sugars. Whole grains and brown rice are preferable due to the presence of added fiber that slows down the body’s processing of these carbohydrates to sugar.
AGEs can also form in foods during cooking, and are another way the body is susceptible to the effects of glycation. Heating enhances the flavor and aroma of foods, but also speeds up the glycation chemical reaction between sugar and protein. Foods cooked with high heat such as roasted, grilled or fried meats, and roasted nuts have very high levels of AGEs³. Diets that are enriched in fresh fruits and vegetables and minimally processed or refined foods will also tend to be low in sugars and AGEs (see Side Bar). Fresh fruits and vegetables have the added benefit of high levels of antioxidants to counteract the effects of glycation.
Lifestyle will also influence exposure to AGEs. For example, cigarette smoke contains chemicals that can form AGEs, and smokers have elevated AGE levels in their circulation4. Exercise may decrease circulating AGEs. Quality of sleep can impact exposure to glycation; impaired breathing conditions such as sleep apnea causes an increase in circulating AGEs.
Side Bar: Glycation and Food
Foods that may Promote Glycation or are enriched for AGEs
- Highly processed grain products (white flour)
- Processed cereals
- Roasted nuts
- Processed or grilled fruits and vegetables
- Full fat, aged cheeses
- Meats, fish and soy cooked at high heat (roasted, broiled, fried) or in the presence of sugar (such as marinades)
- Chips, crackers, pretzels
- Soda, sport drinks, fruit juice, and tea with added sugars
Foods that Minimize Glycation or have low levels of AGEs
- Minimally processed whole grain products (whole wheat)
- Non-instant oatmeal and hot cereals
- Raw nuts
- Fresh fruits and vegetables
- Low fat, fresh cheese
- Meats, fish and soy steamed or cooked at lower temperatures in non-sugary liquid- braised, poached, or stewed
- Air popped popcorn without butter
- Unsweetened fruit juice and tea
Glycation is part of the normal aging process, but its detrimental effects on skin can be minimized through a careful choice of skin care products and keeping a healthy lifestyle. No doubt about it, nature is a powerful force, but nurture can also play a vital role in modifying and even redirecting how nature runs its course in terms of skin health and beauty.
- N. Verzil, J. DeGroot, S.R. Thorpe, R.A. Bank, J.N. Shaw, T.J. Lyons, J.W. Bijlsma, F.P. Lafeber, J. W. Baynes, J.M. TeKoppele (2000) Effect of Collagen Turnover on the Accumulation of Advanced Glycation End Products. J Biol Chem 275(50):39027-31. PMID: 10976109
- M. Yamauchi, P. Prisayanh, Z. Haque, and D.T. Woodley (1991) Collagen Cross-linking in Sun-exposed and Unexposed Sites of Aged Human Skin. J Invest Dermatol 97:938-41; PMID:1919057; http://dx.doi.org/10.1111/1523-1747.ep12491727.
- J. Uribarri, S. Woodruff, S. Godman, W. Cai, X. Chen, R. Pyzik, A. Yong, G.E. Striker, and H. Vlassara (2010). Advanced Glycation End Products in Foods and a Practical Guide to Their Reduction in the Diet. J Am Diet Assoc 110(6):911-16.e12.doi:10.1016/j.jada.2010.03.018. PMID 20497781
- C. Cerami, H. Founds, I. Nicholl, T. Mitsuhashi, D. Giordano, S. Vanpatten, A. Lee, Y. Al-Abed, H. Vlassara, R. Bucala, A. Cerami (1997) Tobacco Smoke is a Source of Toxic Reactive Glycation Products. Proc Natl Acad Sci USA 94(25):13915-13920. PMID: 9391127
Annette Tobia, PhD, is founder of Dynamis Skin Science, which offers the MEG 21 product line (www.meg21/edu). Dr. Tobia earned her PhD from New York University, her post doctoral degree at Rockefeller University, and her law degree from Rutgers School of Law.
Alice Marcy, PhD, is vice president of Dynamis Pharmaceuticals. Dr. Marcy earned her PhD from Johns Hopkins University School of Medicine.