Summers in Tahoe are glorious, but the intense UV rays at altitude mean we have to be diligent about sun protection.
But before you coat every inch of yourself with SPF 100, you might want to consider what a growing number of experts now believe: A little sunshine directly on the skin may actually be good for your health.
The keyword there is little, which means five to 15 minutes of unprotected sun a few times a week on arms and legs. This is not a free pass to get burned, or to even allow the skin to get pink. Nor is it permission to bask in the outdoors for longer than 15 minutes without sunscreen. But brief exposure to sun may offer wide-ranging benefits, including stronger bones, improved mood, and lower blood pressure. It may also reduce the risk of a number of cancers, type 2 diabetes, and several autoimmune diseases.
The evidence is so compelling that even in Australia, a country with one of the highest rates of skin cancer in the world, the Cancer Council now states, “Exposure to a small amount of sunlight is essential to good health.”
Most of the sun’s benefits are due to vitamin D, which our skin makes when we’re exposed to UVB rays. But UVBs are the same rays that cause sunburn, and burning is a major risk factor for melanoma, the deadliest form of skin cancer.
Most of us don’t have to try to get a little unprotected sun. You might easily get a dose chatting outside with a neighbor. But if you’re a staunch follower of sun safety protocol — gooping up and covering up every inch of skin from morning till night — you could be depriving yourself of vitamin D.
Technically a hormone, vitamin D is crucial to human health. Low levels have been associated with weight gain, type 2 diabetes, osteoporosis, infections, autoimmune diseases, shorter lifespans, and more than a dozen different cancers.
Sunlight isn’t the only way to get your Ds. Other sources include supplements and food, though it’s hard to get enough from food alone. Very few foods naturally contain the vitamin. Primarily, cold water fish and fortified foods like milk, OJ, and cereal contain relatively small amounts. Can you skip the sun altogether and get all your Ds from supplements? Theoretically, yes, but it takes some experimenting and blood tests to ensure you’re maintaining optimum levels; too much vitamin D can be toxic.
The advantage of sunshine is that it’s an easy prescription for almost everyone to follow. A 10-minute stint a few times a week provides the average person with adequate vitamin D. The disadvantage, explains Truckee dermatologist Diane Kamenetsky, is that many people won’t stop at 10 minutes, and any additional exposure increases your risk of multiple skin cancers.
“If you have adequate vitamin D levels, you don’t need to expose yourself to more UV rays,” says Kamenetsky. “And if skin cancer runs in your family, you should think twice about getting your vitamin D from the sun.”
Though vitamin D is best known for helping maintain strong bones, research indicates it may play an important role in combating many diseases as well.
An Irish study found that low vitamin D levels were linked with a 75% increase in depression. Seasonal depression is common at northern latitudes, where people can’t make vitamin D during the winter months. Here in Tahoe, that “low sun” period extends from November through February. Though our bodies can store vitamin D for use during the winter, many factors — including genetics and how much D we get from food or supplements — determine whether our levels stay adequate throughout winter.
Low blood levels of vitamin D have been linked with a higher frequency and severity of multiple sclerosis (MS), lupus, rheumatoid arthritis, and psoriasis.
Research worldwide shows that rates of at least 15 types of cancer are highest at northern latitudes, where people get the least amount of sun. This is true in the U.S., where rates of prostate, breast, colon, and seven other cancers are highest in the northern states.
When it comes to skin cancer, however, the pattern is reversed, with higher rates in the sunnier South and Southwest. So, if you plan on getting vitamin D from the sun, it’s critical to minimize exposure and never get burned. It’s also a great idea for everyone to get an annual skin exam.
DON’T GET SCORCHED!
• UV radiation is 18% stronger at Lake Tahoe than at sea level and increases 3% with every 1,000 feet of elevation. Reflective surfaces like water, sand, and snow intensify UVs. If you’re light-skinned, even a few minutes without sunscreen could burn you at altitude.
• Mineral sunscreens like zinc oxide work immediately, while chemical sunscreens (oxybenzone, etc.) take about 15 minutes to become effective.
• Many medications and herbs increase sun sensitivity, including some antibiotics, St. John’s wort, Benadryl, and NSAIDS like ibuprofen and aspirin.
• Tightly woven denim and poly block more UVs than looser weaves like cotton and linen, but all clothing was shown to block the skin’s formation of vitamin D. Some clothing is SPF rated; a value of SPF 50 lets 1/50 of the UV rays through.