Tempting as it is to avoid the summer heat, the sun can also be your friend – if you're careful.
Dr. Carlos Galindo of Texas Health Family Care, a Texas Health Physicians Group practice, explains how and why to KERA's Sam Baker.
Dr. Galindo: Sun is essential for vitamin D. It's also referred to as the sunshine vitamin. Sun hits the skin and through a cellular process, the cholesterol-like type of substance is then converted into the body to vitamin D and then we absorb it in our body.
Baker: Which does what for us exactly?
Dr. Galindo: Blood pressure control, immune function, bone function, and strength. It can also be linked to mood regulation and the sleep-wake cycle.
Baker: How much sun, though, do you need to get an adequate amount?
Dr. Galindo: Five to 15 minutes, two to three times a week, particularly during the midday hours. So, from about 10 a.m. to about 3 p.m., at that exposure level, you generally get all the vitamin D your body really needs.
The body has an amazing mechanism to kind of shut off any excess of vitamin D beyond those parameters.
Baker: So what's the best way of going about getting that at that time of day?
Dr. Galindo: Wear some sunscreen. Generally, you want to use an SPF 50 or higher and some women's facial creams, lipsticks have SPF protection in there. So, when you do go outside and you're going to be spending more than just a casual amount of time outdoors, it's best to apply that sunscreen.
Baker: But as you mentioned, the sun can be harmful if you're not careful, how so?
Dr. Galindo: When you start getting excess amounts of sun exposure, the incidence of skin cancer increases. And skin damage is more of a cumulative process.
So, when we're born as children and we go into adolescence, young adulthood, the amount of skin damage can build up over time. Our body has an innate system of repair mechanisms. So if there's sun damage and there are changes in the DNA, our skin has a repairing mechanism to help prevent skin cancers and get rid of early disruptions in cell cycle that if not checked can lead to skin cancer.
But unfortunately, as we get older, those repair mechanisms become less effective. And that's why the incidence of skin cancer is higher as we get older. So, as we get older, if you see a skin spot on your body, certainly get checked by your doctor.
Baker: So what's the best way to try to protect yourself?
Dr. Galindo: The vast majority of Americans, when we apply sunscreen, we don't apply enough. A general rule of thumb is when you apply sunscreen you want to consider a shot glass, which is about an ounce worth of liquid, for the whole body.
You can take a little dab of that shot amount, apply it to the face and neck, a little dab or a teaspoon to each arm, and about two teaspoons to the front torso and each leg. And you want to be sure to reapply the sunscreen every two hours. That will serve as a barrier for damaging UV rays, still getting that tan, but providing protection at the same time.
Baker: What do you say to patients who tell you "these temperatures are too hot. As much as possible, I stay indoors. I don't go outside at all."
Dr. Galindo: That can work against us as well, because if we're indoors too much, that can lead to low levels of vitamin D. In fact, a lot of Americans are deficient in vitamin D, particularly darker pigmented individuals - African Americans, Hispanics, Latinx individuals - because we have more of a pigment barrier. Couple that with staying indoors more, that can really compound lower vitamin D levels, which can be problematic.
RESOURCES:
12 Ways the Sun Affects Us: Positive & Harmful
The Health Benefits of Sunshine (and How Much You Need Per Day)
How Spending a Little More Time in the Sun Can Help You Live Longer
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