Good news, coffee lovers: Your several-cup-a-day habit might help protect you from skin cancer.
“We estimate that 400,000 skin cancers are prevented annually by drinking caffeinated coffee in the U.S.,” says Masaoki Kawasumi, M.D., Ph.D., a UW Medicine skin cancer researcher.
It doesn’t work with decaf.
That’s because caffeine inhibits an enzyme called ATR, which plays a key role in the survival of cells damaged by ultraviolet (UV) rays. Inhibiting ATR can eliminate UV-damaged cells that are precancerous. Because decaf coffee doesn’t contain caffeine, it doesn’t have this effect.
Kawasumi and his colleagues have demonstrated that inhibiting ATR in a mouse’s skin prevents the development of UV-induced skin cancer. Their work has shed light on how caffeine prevents skin cancers at a molecular level.
You still need sunscreen.
You would think Washingtonians’ love of drinking coffee means we’re protected from skin cancer. But the state actually has a higher melanoma rate than many others, including sunny California. This may be due to unprotected sun exposure, Kawasumi says.
“Sunscreen needs to be applied to the skin even in Seattle's cloudy climate, in particular for those with fair skin,” he says.
You'd have to drink a lot of coffee.
Despite the health benefits of caffeine, using it in daily life to prevent cancer can prove difficult. For starters, it must be ingested or applied to skin immediately before or after exposure for full effect, and not many of us take coffee with us to the beach. Previous studies also show that the more caffeine you consume, the stronger the preventive effect—but the average American only drinks three cups a day, Kawasumi says.
“It’s not so realistic to drink coffee more to completely inhibit skin cancer,” he says. “If people like drinking coffee, continue enjoying your coffee, but we want to have a more efficient way of using more potent caffeine.”
Caffeine cream may be in your future.
Kawasumi and his colleagues are currently working on finding out when is the best time to apply a topical caffeine cream in order to prevent skin cancer. They are also working on developing what Kawasumi calls "better caffeine": small-molecule compounds that are more potent in preventing skin cancers, with the hopes that they will someday provide an easy way for people to protect themselves.
Get java jitters? Caffeine may not be as helpful for you.
Caffeine’s benefits may extend beyond skin cancer prevention. A human study conducted in 2012 revealed that coffee consumption is associated with reduced risk of total mortality.
However, not all coffee drinkers are created equal. While the outdated belief that caffeine contributes to medical problems like heart attack and stroke has mostly been debunked, research shows that how someone metabolizes caffeine could determine whether or not it improves their health.
The study found that people who metabolize caffeine more slowly may be at higher risk for heart attack, but people who metabolize caffeine quickly—those who can drink multiple cups a day without getting jittery, for instance—may reap health benefits from it.
A review of caffeine research showed that drinking less than 400 mg of caffeine per day—or about four 8 oz. cups—has no immediate adverse effects on health. So if you enjoy coffee and it doesn’t cause problems for you, keep at it—and go ahead and rock that ‘death before decaf’ mug.