As we get older, our skin is one of the first places the years start to show. Damage from long-term sun exposure causes the skin to wrinkle and become discolored. But some people seem to hold up better than others. Is it thanks to good genes or to environmental factors?

To tease out the associations between environmental factors and skin aging, researchers controlled for genetic influences by studying twins.

Each member of sixty-five sets of twins, ages eighteen to seventy-seven, was assigned a skin damage score based on factors such as wrinkling and skin discoloration. Then the participants were asked to complete a questionnaire about behavioral and environmental factors.

Cigarette smoking and a history of skin cancer were strongly linked to skin aging, according to the findings, published in the Archives of Dermatology.

And the heavier people were, the more damaged their skin was… except for folks older than fifty-four. For them, higher weight corresponded with less skin damage, possibly because excess fat can mask the appearance of wrinkles.

Interestingly, higher levels of alcohol consumption corresponded to lower levels of damage, perhaps because of antioxidant compounds such as resveratrol, which is found in red wine.

Protecting against sun damage can help people age in a healthier way, and there are simple ways to avoid excessive sun exposure. Protect your skin with long sleeves, long pants and wide-brimmed hats. Wear sunscreen with an SPF of at least fifteen, which protects against both UVA and UVB rays. And limit the amount of time spent in the sun, especially from 10 a.m. to 4 p.m.