Sweets connect us to so many positive life memories, from our first birthday cake (and every one thereafter) to the fun of Halloween and Easter, to hot chocolate after ice skating. But sugar has a dark side — and it's not just that over time it becomes fat (as if that isn’t bad enough).

Sugar has other negative effects too, including accelerating how fast our skin ages, and it’s bad enough to rank up there with the kind of damage cigarette smoking can cause to skin, research shows. (Now if only I could imagine a piece of chocolate cake as a pile of cigarette butts, I’d never eat sugar again!)

Over the past five years, research from diabetes studies has looked at what happens when sugar enters our bodies — and it’s not great news for those of us with a sweet tooth.

When you consume something sweet, the sugar molecules shoot into the bloodstream, and there they glom right onto fats and proteins; this is glycation.

Once attached, these sugar-plus-protein molecules form what are called advanced glycation end products (AGEs), which are then much more stiff and irregularly shaped than the protein-only cells, which are typically slippery and move easily through blood vessels. Once glycation takes place, however, this now-sticky blood moves more slowly and has trouble moving through smaller vessels and capillaries.

Processed (white) sugars and high fructose corn syrup flow into the blood stream more quickly than fruits or other carbs that take longer to digest, but the process happens with any sugar.

In diabetics, blood sugar levels are continually elevated, and it’s this glycation that’s been linked to connective-tissue damage and chronic inflammation. When it goes on for too long untreated, it can result in tightening of blood vessels (never a good thing), pancreas and liver diseases, cataracts, Alzheimer's and other health issues.

For those of us without diabetes, sugar still has some very real and negative effects; what keeps our skin looking young are the proteins collagen and elastin — and remember that it’s proteins getting attached to sugars that makes them lumpy and slow-moving. What this means in the dermis is that those AGEs end up discoloring skin and making it less soft and weaker overall. That leads to wrinkles, sagginess (like jowls and drooping eyebrows) as well as a general loss of brightness.

And to add insult to injury, those AGEs actually weaken skin so that other skin-attackers — like cigarette smoke, environmental toxins and too much sun — do even more damage than they would have on their own. As New York–based dermatologist Cheryl Karcher, MD, told Elle magazine: "Number one, the glucose makes the cells abnormal; and number two, it creates free radicals. So you get a double whammy when it comes to aging."

None of this damage, whether from sun, smoking, or glycation, really shows up until around ages 30-35, when all of our self-abuse (or some would say, life), adds up.

"When you're younger, your body has more resources to ward off damage, and you're producing more collagen," New York- and Miami-based dermatologist Fredric Brandt, MD, told Elle. "When you reach a certain age, these sugar byproducts begin to build up at the same time that your threshold for damage is getting lower."

Not all of the effects of glycation are within your control, but some are: “One of the most effective ways to reduce glycation and to reduce that stickiness so that blood is flowing is to not get our blood sugar so high in the first place so it doesn’t have that excess sugar to glom up the works. How do we do that? With a lower-carb diet,” says Dr. Jonny Bowden, PhD, a nutrition specialist who talks about glycation and aging in the video above.

Liver spots are an example of glycated proteins that can be seen on the skin, according to Bowden.

To some extent, aging is a perfectly normal process, and if you eat food, you’re going to have some glycation take place (all carbs get converted into sugars, even otherwise healthy ones, like brown rice and whole fruits). But you can tip the balance in your favor by slowing down the process and avoiding white sugars, high fructose corn syrup and any simple carbs, like processed flours.

And while researchers are looking into topical treatments, green tea has been found to both interfere with the glycation process and as a bonus, it also stimulates collagen production. Old glycated collagen can eventually be replaced by new, healthier versions of the protein, so you can undo some of the damage that’s already done.  

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