Susan Sarandon, whose latest movie Robot & Frank, is about to be released, is in her mid-60s. She says she has never had fillers or Botox, but does gamely admit to a little nip and tuck: “I had under my chin sucked out once.” But the thing she attributes most to looking great for her age is quitting smoking.

“It’s not age that causes some of the damage, but eating poorly, drinking and smoking that really wrecks havoc over the years,” she says. “Young actors ask me: ‘Why is your skin so great; what is your product?’ and all I say is: Stop smoking, that’s the big one.”

I smoked cigarettes for 25 years and when I stopped I can’t say I noticed my skin looking any different. That’s not to say, I don’t believe that smoking can be aging and destructive. I’m just curious as to the hows and whys and so I set about finding out more about Susan Sarandon’s beauty secret. On the way, I encountered a fair amount of smoke and mirrors.

So much so, that I even began to wonder if the whole thing was an urban myth. Most references, even apparently academic ones, make do with generalizations. Such as this one from the American Academy of Dermatology: Cigarette smoking causes biochemical changes in our bodies that accelerate aging.” Frustratingly, they don’t go into what those biochemical changes are and what it is about nicotine that causes them.

The Mayo Clinic is more specific, saying that nicotine “causes narrowing of the blood vessels in the outermost layers of your skin. This impairs blood flow to your skin. With less blood flow, your skin doesn't get as much oxygen and important nutrients, such as vitamin A.”

This theory is taken up by others and, indeed, taken further to say that this impaired blood flow to the skin results in broken capillaries. Maybe. But not all smokers have broken capillaries and many people who have never smoked do. The impaired blood flow is also deemed responsible for slower wound healing, due to too much carbon monoxide and not enough oxygen.

None of it was very convincing and then I found a study on smoking and aging skin published in Genome Medicine, linked the damage that smoking causes to oxidative stress.

Smoking and oxidative stress makes sense and, indeed, there’s plenty of hard research on it. Happily, the researchers in Genome Medicine hit on an antidote – supplements of fatty acids. They concluded that “long-chain fatty acids can lead to increased glow, improved elasticity measures and decreased fine wrinkling in smokers’ skin.”

Now this interesting because it suggests that antioxidants, especially fatty acids, can help undo damage from smoking. This might explain why I didn’t see a huge improvement in my skin when I stopped smoking cigarettes (age 40) until I was in my late 40s and was using a ton of topical antioxidants and had dramatically changed my diet to one very much biased towards antioxidant-rich fruits and veggies.

I also found plenty of evidence that smoking increases MMP levels – that’s matrix metalloproteinase-1, an enzyme that chops up proteins. As collagen is a kind of protein, increased MMP can lead to the degradation of collagen, elastic fibers, and proteoglycans. The same study also noted that reactive oxygen species are also involved in tobacco smoke-induced premature skin aging. Scavengers of reactive oxygen species help to bring MMP down.

So, the lesson seems to be to stub out the ciggies for good, as Susan Sarandon did, and to reach for superfoods (here are some suggestions of foods brimming with antioxidants)  and topical creams and serums that major on radical scavenging ingredients such as spin trap or Lipochroman-6.