But as Vince Sherry reports, a new study shows that caffeine might help inhibit, and possibly even reverse, damage to skin caused by the sun.
That double shot of caffeine in your morning cup of latte may be good for more than just a wake-up jolt.
New research on mice shows it may also prevent skin cancer.
Doctor Paul Nghiem said, "for some time, we've known that caffeine appears to be able to prevent skin cancer. There's epidemiological data along those lines and the interesting more recent thing is that caffeine appears to be able to do that when you apply it topically."
Researcher Paul Nghiem and his colleagues studied the skin cells of mice damaged by ultra-violet rays.
They found that caffeine, when applied directly to the damaged skin, blocked pre-cancerous cells from dividing and becoming skin cancer.
Doctor Nghiem added, "caffeine, at least in mice and in cells, can reverse that damage in part by actually getting rid of the cells that are most damaged, so that more healthy cells can grow in."
Researchers used caffeine like this, mixed with a solution, to treat the mice.
But in the future, it may just be easier to add caffeine to sunscreen for human use.
"It's very possible that ultimately it may make sense to put it into a sunscreen where it would be there to block the sun in the first place and then to help reverse the damage that does get through the sunscreen," said doctor Nghiem.
Human studies will be required to show if caffeine can help prevent skin cancer in people, but for now, ordering that extra shot of caffeine might not be a bad idea.
Researchers don't believe caffeine would ever be an effective treatment for an established skin cancer.
The benefits are clearly in preventing damaged skin from becoming cancerous.