Advice you may not hear from your doctor: Don’t go out in the sun without protection

I’m a Long Island boy, so growing up often meant spending eight to 10 hours at a stretch playing in the sea surf with my four brothers at Jones Beach, fishing for flounder off the town docks, skin diving around stone jetties the Sound, or treading for clams in the mudflats at the mouth of the Nissequogue River.

In all those years, I don’t recall hearing the words “Put on sunscreen” pass from my mother’s lips. (I did often hear “Stop throwing shells at your brother” and “Be back here at 4 p.m. or I’m leaving without you.”)

How times have changed. Getting ready to frolic in the sun now reminds me of the kind of checklist astronauts on the International Space Station need when suiting up for a 6-hour spacewalk in the full blast of the sun’s radiation. Today, my mom might have taped a list like this to the door:

• Put on sunscreen 20 to 30 minutes before you go out.
• Use a broad-spectrum sunscreen that blocks ultraviolet A and B, with a sun protection factor (SPF) of at least 30.
• Use a full ounce (enough to fill a shot glass) to cover every exposed surface.
• Reapply every two to three hours, or if you frolic in the surf or sweat profusely while throwing shells at your brothers.
• Wear a wide-brimmed hat.
• Wear clothing with a tight weave or with chemical treatments to make them UV-resistant.
• Apply lip balm containing sunscreen.

Roger that, Houston. It seems the only thing missing is the gold-plated spacesuit helmet and a T-shirt for mom that says “Radiation Safety Officer.”

It’s all for a good cause, says my go-to sun protection officer at Harvard Medical School, Dr. Daniela Kroshinsky. As a medical dermatologist at Massachusetts General Hospital, she sees the long-term outcomes of repeatedly frying yourself in the sun—skin cancer and skin aging.

Her bottom line, in an article in the August 2014 Harvard Men’s Health Watch, is this: “Melanoma is on the rise. We really advocate that people take sun-protective measures and notify their doctors of any concerning or changing spots on their bodies.”

We’ve been told countless times that regular use of sunscreen prevents melanoma skin cancer—the most dangerous kind of skin cancer because it can spread to distant sites in the body and lead to death. But according to a research review article this week in the Journal of the American Medical Association, not all doctors share Dr. Kroshinsky’s enthusiasm for the gospel of sun protection.

The article points to a recent study in JAMA Dermatology of 18 billion outpatient visits from 1989 to 2010. It found that doctors made a note that they mentioned sunscreen at just 0.07% of patient visits, or roughly 1 in 1,400 visits. Dermatologists did better, mentioning sunscreen 11.2% of the time during visits that were expressly related to skin cancer past or present.

If it sounds like doctors don’t care about sun protection, don’t jump to conclusions. The records scrutinized in the study show only mentions of sunscreen that physicians consciously noted in the official record. They may have mentioned it and not recorded it.

And besides, everyone knows that sunscreen prevents cancer—don’t they?

Does using sunscreen prevent cancer?

It may surprise you that public health experts debate the merits of doctors offering sun-protection advice to their patients. Why? The evidence is spotty that advice from doctors on prevents cancer, according to a 2012 recommendation by the U.S. Preventive Services Task Force (USPSTF). The USPSTF is a panel of experts who weigh the evidence for the kinds of things primary care doctors do—like giving out sun protection advice, or urging their patients to stop smoking and eat healthier.

The USPSTF found that the best evidence we have says that sun protection counseling for fair-skinned folks age 10 to 24 helps prevent skin cancer, and does not appear to have any downsides for health.

As for those age 25 and up, we simply don’t have enough good evidence to say that “doctor’s orders” regarding sun protection reduces skin cancer. I asked a confessed sunscreen proponent, Dr. C. Douglas Taylor, Chief of Hematology and Oncology at the Cambridge Health Alliance in Boston, what he thinks of the USPSTF’s partly cloudy sunscreen recommendation.

“In the end you come to conclusions and do interventions based on the best evidence and common sense,” says Dr. Taylor, who is also an instructor in medicine at Harvard Medical School. “I think it’s quite clear there is an impact of regular sunscreen use on skin cancer, including melanoma, and on skin aging.”

To be fair, Dr. Taylor does have a bit of a pro-sunscreen bias. If you were at the June 2014 Boston Dragon Boat Festival on the Charles River, you would have seen his colleagues toting around gallon-sized pump jugs of sunscreen. In fact, he’s a bit of a Pied Piper of sun protection.

“You could have a high potency sun blocker, SPF 30 and above, available at public venues, like at your backyard or neighborhood swimming pool, boat club, or rowing club,” Dr. Taylor says. “A gallon jug that would be instantly available for everyone and it would last a long time. I don’t know that they would make this available to letter carriers at the US Post Office, but they really ought to!”

Running for health: Even a little bit is good, but a little more is probably better

Daniel Pendick, Executive Editor, Harvard Men's Health Watch

Marathoners are the thoroughbreds of high-performance runners, but even the draft horses of the running world — slow and steady joggers — improve their health. A study out this week in the Journal of the American College of Cardiology finds that even five to 10 minutes a day of low-intensity running is enough to extend life by several years, compared with not running at all. It shows that the minimal healthy “dose” of exercise is smaller than many people might assume.

But if your favorite activity is a brisk walk in the park or a quick game of tennis, the research has implications for you, too. “There is no question that if you are not exercising and if you make the decision to start — whether it’s walking, jogging, cycling, or an elliptical machine — you are going to be better off,” says cardiologist Dr. Aaron Baggish, the associate director of the Cardiovascular Performance Program at Harvard-affiliated Massachusetts General Hospital and an accomplished runner himself

Take five to stay alive

The new study focused on a group of more than 55,000 men and women ages 18 to 100. About a quarter of them were runners. Over 15 years, those who ran just 50 minutes a week or fewer at a moderate pace were less likely to die from either cardiovascular disease or any cause, compared with those who didn’t run at all.

The study suggests a relatively low entry level for the benefit of jogging, but it is not a prescription. “A little bit is good but a little bit more is probably better,” Dr. Baggish says. A 2013 study in Denmark suggested that the “sweet spot” for maximum longevity is up to 2.5 hours of running a week.

Although running can trim away some of your existing risk of cardiovascular disease, it doesn’t entirely eliminate it. The combined effect of lifestyle, diet, and family history still contribute to your lifetime risk.

“There is no question that the fitter you are and the more exercise you do, the longer you live and the better your quality of life,” Dr. Baggish says. “But it doesn’t confer immunity.”

Feeling better

This study used preventing death to measure the benefit of running, but it’s not the most typical reason for running. “Many dedicated long-term runners do not run because they want to live longer,” Dr. Baggish notes. “They run because it makes them feel better on a daily basis. There is a mood elevating, quality-of-life benefit that comes from being a regular exerciser.”

For regular runners, the cost of feeling good can be strains and sprains, so Dr. Baggish advocates for the value of what he calls “active rest.” His rule of thumb, not supported by any specific research, is that it’s a good idea to spend 25% of exercise time over the course of a year running at a lower level of intensity or doing other activities like swimming or biking.

“The body responds to training, but to preserve that benefit over the long haul there needs to be active periods of recovery,” Dr. Baggish says. “Pulling back allows the body to repair and heal.”