There’s no way to sugarcoat it: Consuming too much of the sweet stuff is as damaging to your skin as it is to your waistline. To blame is a natural process known as glycation, during which the sugar in your bloodstream attaches to proteins to form harmful new molecules called advanced glycation end products (or, appropriately, AGEs for short). The more sugar in your diet, the more AGEs you develop.
It’s particularly sour news that the skin proteins most susceptible to glycation are collagen and elastin, the same ones that make a youthful complexion so plump and springy. When bonded with excess glucose, the type of sugar that fuels glycation, these normally resilient fibers become stiff and inflexible. “This damage leads to an increase in fine lines and wrinkles and imparts a sallow tint to skin,” says Doris J. Day, M.D., clinical associate professor of dermatology at New York University Langone Medical Center. Adding insult to injury, AGEs also interfere with the production of new collagen and elastin, making repair efforts difficult.
While glycation can’t be completely stopped, it can be slowed. “Prevention is key,” says Mark Rubin, M.D., assistant professor of dermatology at the University of California, San Diego, and coauthor of Your Skin, Younger. “Once collagen is damaged by glycation, it’s resistant to reversal.” Heed this advice to help keep AGEs away from your skin:
•Cut back on sugar
It’s impossible to eat a balanced diet and eliminate sugar completely—even whole grains, fruits, and vegetables turn to glucose when digested. But limiting added sugar can help. Aim to have no more than 100 calories per day from added sugar (that’s about 6 teaspoons). Food for thought: Women ages 20 to 39 consume more than two and a half times that amount.
•Rethink cooking methods
“When it comes to AGE formation in food, moisture matters,” says Rubin. Foods cooked for extended periods with high and dry heat (think oven-roasted, grilled, or fried) are AGE heavyweights. Foods prepared in the presence of moisture by boiling, poaching, or steaming are skin-friendlier. For instance, crispy rice cereal contains 220 times more AGEs per gram than boiled rice, and a fried egg has 62 times more AGEs than one that’s poached.
•SPF 30 sunscreen daily
Significantly more AGEs occur in sun-exposed skin than in protected skin, according to a British Journal of Dermatology study. AGEs also deactivate your body’s natural antioxidants, leaving skin more vulnerable to UV damage.
•Use targeted skincare
Luckily, anti-AGEing products are becoming all the rage. One of the most effective is GlyTerra-gL, a system that contains Theraglycan-3, a complex that includes albizia julibrissin, a patented extract of the silk tree. When tested in clinical studies, these products—which also pack skin-firming peptides and age spot–reducing compounds—produced a reduction in AGEs that made women look like and register a glycation reading of someone up to a decade younger. Sweet! ($135 for a 30-day supply; glyterra.com)