The problem with tanning (and the myth of the base tan)

Robert H. Shmerling, MD

Senior Faculty Editor, Harvard Health Publishing

Follow me on Twitter @RobShmerling

Are you a person who loves to be tan? Do you pine after the bronzed look of jet-setting celebrities just back from the tropics?

If so, you’re not alone — let’s face it, we’re a culture that’s obsessed with being tan. It’s attractive, fashionable, and a sign of good health, right?

Actually, sun exposure or spending time in tanning booths has many health experts worried: it damages skin and increases the risk of skin cancer. The risk rises if tanning leads to a sunburn — according to the American Academy of Dermatology, a single blistering sunburn can nearly double one’s lifetime risk of melanoma, the most deadly form of skin cancer. So, it’s ironic that one of the reasons people tan is to look healthier.

The prevalence of skin cancer (and the costs of its treatment) is rising: nearly five million people in the United States will be treated for skin cancer this year (an increase of 50% from the prior decade) at a cost of more than $8 billion (twice the cost of a decade earlier).

The myth of the base tan

Have you heard of the idea of a base tan? It may seem reasonable enough: before you head off to the beach for vacation, getting a tan ahead of time might help you avoid burning, and there’s the added benefit of not looking pale when you first arrive.

So does a base tan prevent burning? Experts estimate that going out in the sun with a base tan is equivalent to wearing a sunscreen with a sun protection factor (SPF) of 3 to 4. This means the skin can be exposed to up to four times more sun before burning than without the base tan. For example, if you would ordinarily burn after 20 minutes in the sun, a base tan might mean you can be in the sun for up to 80 minutes before burning. While it’s better than nothing, it’s a modest benefit; most recommended sunscreens have SPFs of at least 15 to 30. Since wearing sunscreen is much more effective than relying on a base tan to protect you from burning, the real question is whether having a tan on day one of your vacation is worth the time and expense at the tanning salon before you leave.

Tanning among teens is a particular concern

The earlier one starts tanning, the longer the lifetime skin damage and the higher the skin cancer risk. So there has long been worry about teenagers who spend hours tanning outside or in tanning booths. Because of this concern, a number of states have passed bans or restrictions in recent years requiring parental consent for teenagers to use tanning booths. In 2009, only five states had such restrictions; in 2015, 42 states did.

And it’s working. According to a study of more than 15,000 U.S. high school students, indoor tanning decreased from nearly 16% in 2009 to just over 7% in 2015. But that’s still a lot of kids — a million or so in the U.S. — putting themselves at unnecessary risk.

What about vitamin D?

There’s been controversy for years regarding safe levels of sun exposure. Some suggest that we should not limit sun exposure too much, because the sun helps increase stores of vitamin D by converting inactive forms of the vitamin in the skin to the active form. This reaction takes far less time than tanning. And vitamin D can be good for your bones, your immune system, and perhaps other parts of the body.

Meanwhile, warnings about the dangers of tanning and sun exposure argue that even brief exposure to intense sun can damage skin and increase cancer risk. And, there are other ways to get vitamin D, such as dairy products and supplements. In my view, it makes little sense to justify sun worship by invoking the health benefits of vitamin D.

So what’s a tan-lover to do?

If your goal is to get a good suntan (or to look like you have one the day you arrive at the beach), think about using “sunless” tanning lotions, gels, or sprays that temporarily stain the skin. You’ll still need sunscreen, though, as these products do not protect against sunburn.

Better yet, rethink whether you really need a tan to look good. After all, today’s swarthy glow is tomorrow’s wrinkled, weathered, leathery hide — or worse, skin cancer.

If your goal is to prevent sunburn, there are better options than getting a base tan:

  • Stay out of the sun when the sun in most intense (from about 10 a.m. to 3 p.m. in most of the United States).
  • Use sunscreen liberally: choose a sunscreen that offers an SPF of at least 15 to 30 and protects against both UVA and UVB radiation. (This is also called “broad spectrum.”) Re-apply at least every two to three hours, more often if you’ve been sweating, swimming, or rubbing your skin with a towel.
  • Wear protective clothing: a long-sleeved shirt, wide-brimmed hat, and long pants offer good protection from sun exposure. Dark fabrics that are tightly woven are best.

These measures are most effective in combination, and are particularly important for children or for anyone with fair skin. Remember that you can burn even on cloudy days. Check your local UV index, which predicts the level of UV radiation and indicates the risk of overexposure on a scale from 0 (low) to 11 or more (extremely high). The National Weather Service calculates the index for most ZIP codes. You can search for the UV index in your ZIP code on the Environmental Protection Agency’s website, or download its mobile app.

What’s next?

As with most public health worries, we need more research. For example, how do you know when you’ve had too much sun? It’s not always easy to know when you’ve been out too long and passed the point of no return for a sunburn.

We need more education to correct misconceptions about tanning (such as the myth of the “healthy tan” or the benefits of the base tan), and we need to teach kids, parents, and schools that teens should avoid too much tanning, whether indoors or outside.

Perhaps the decline in indoor tanning by teenagers and the efforts of some celebrities (such as Nicole Kidman) to discourage tanning are indications that we are now moving in the right direction.

Related Information: Skin Care and Repair


  1. Randy Green

    Sensible sun exposure has numerous benefits besides vitamin D, a lot of them listed by Marc Sorenson, above. Even a cursory survey of scientific papers shows these benefits.

    Vitamin D has been produced by animals almost since they first evolved – there are almost no natural sources of D in natural food, except for livers of some fish, seals, polar bears, etc. In edible plants, D sources are limited mainly to sun-exposed live mushrooms.

    So people cannot get the necessary levels of D through their foods unless the foods are supplemented, like in milk, or through nutritional supplements. From an evolutionary biology standpoint (I’m a biologist), doesn’t this seem suspicious?

    As Marc stated above, there are many other benefits to sensible sun exposure besides just vitamin D: for example lower blood pressure due to increased nitric oxide and mitigation of the renin/angiotensin pathway.

    Plus, correlational data (yes, correlation is not causation) shows that certain diseases like multiple sclerosis, heart disease and many common cancers are inversely correlated with latitude: these diseases are more prevalent the higher in latitude one lives (the further you get from the equator). Many studies show that the increased risk of skin cancer from sensible sun exposure is far less than the decreased risk of other internal cancers and heart disease.

    There is also the issue of some sunscreens possibly aiding in cancer formation and other illnesses. Go back and look at the last 60 years of sunscreens that were determined to have health issues that have been discontinued (remember PABA?).

    While one should certainly not overdo their exposure, especially if you have certain fair skin types, some sun is absolutely necessary for decent health. Our ancestors did just fine for millions of years, otherwise we wouldn’t be here!

    Should we avoid fresh air because oxygen is a component in the production of damaging free-radicals? Is it possible that other things in our diet or environment are interacting with excessive sun exposure to produce increased skin tumors?

    We’ve become a generation of heliophobic troglodytes (sun-fearing cave dwellers). Time to re-examine this topic more objectively.


      Thank you, Randy Green, for your great comment that lists many of the
      arguments for (moderate, sensible, gradual …) sun exposure.
      Dr. Shmerling’s blog reflects the still prevailing view of most dermatologists who disregard stubbornly the scientific findings of the
      past ten to fifteen years that support reasonable (skin-type and location-
      specific) sun exposure such as can be found in the work of Profs. Holick,
      Vieth, Garland et al. Of course, much depends on the skin type: if you are
      type 1 stay out of the sun and cover up. If you are skin type 2-3 take it easy
      and build up a tan slowly and enjoy your sunbath (still “in moderation”).
      Beyond skin type 3 the precautions and rules barely apply even though
      a dark-skinned person may get skin cancer once in a blue moon.
      Which leads us to another hardly ever mentioned aspect of this controversial discussion: The (IMO ill-advised) opinions and warnings
      by the Dermatology establishment apply mainly/almost exclusively to
      “fair”-skinned populations, it is a problem of “white” people that live in or
      came from Northern latitudes. The great majority of the world population
      does not experience the skin cancer problem (“epidemic”?) of Caucasians because their skin is brown or black …pre-tanned by Nature.
      Skin cancer is rampant among the (white) immigrant population of
      Australia, but certainly not among Aborigines. There seems to be a certain rather narrow (racially prejudiced?) view of the “tanning problem”.
      Tanned skin is desirable in many but certainly not all cultures. Where I live,
      in Hawaii, it is a natural result of our environment (unless you hide from the sun and heed Dr. Shmerling’s advice, which results in Vitamin D deficiency as in the majority of Hawaii residents – rather ridiculous !).
      I like to blend in with the rest of the totally mixed Hawaiian population
      that shows all healthy skin pigmentation shades from white to black.
      Ola La (Hawaiian for “Health from the Sun”)

      • Bob

        I think the message is about reducing skin cancer rather than the downside of not getting Vit D. The problem should be stated as how do you reduce the number of skin cancers relating to sun damage as the public message is obviously not getting through. I agree with all that is said in regards to Vit D but then armed with that knowledge what will people go and do and will skin cancer numbers go up or down if that is the primary focus. Some sun exposure is needed for optimal health but obviously people can not be trusted to act responsibly towards that goal or are not asking the right questions or getting the right answers. Even with this negative message about sun exposure I would pessimistically think it will have little impact on the stats. Tough one to solve perhaps a new approach is required.

    • mike gudman

      Sunburns will give you skin cancer guaranteed, and the dead from it is fast and very painful. So go and catch some sun you idiots. You will look good in your casket.

  2. Tim

    To tan or not to tan that is the question. The author obviously thinks not. Not all end up with a leather hide maybe the people that overdo it. Why not present the facts (instead of inserting your opinion) and let the reader decide how they look “best”.

  3. June Ross

    Ten years ago, I developed agonising muscle pain and myriad other symptoms. In those days, GP’s didn’t consider vitamin d deficiency. So, I did my own research, started myself and my husband on 10 k D3 daily for six weeks, at which point we got our levels checked. It was the month of June. They were just about within normal levels, so we used a maintenance dose from thereon in. What we noticed then, and every year since, is that, if we maintain our levels, and start exposing skin from the earliest possible sunshine, we never burn (my husband has fair skin, freckles and used to have ginger hair!). It seems that, if one has enough D3, it acts as a protection against burning. I also discovered this fifty years ago when I lived in Spain for a year as an 18 year old, and built up a tan gradually from the earliest sunny weather. I never burnt at the height of summer. There was no sun screen in those days!

  4. Marc Sorenson

    Do you realize that sun deprivation has been shown, in a recent study, to lead to the death of 330,000 people per year? Did you also realize that women who use sunbeds over a -year period have a 23% reduced risk of all-cause mortality? It would be wise to know all the facts before printing anti-tanning articles. Here are a few well-documented facts regarding sun exposure:
    •A 20-year Swedish study shows that sun avoidance is as bad for the health as cigarette smoking.
    •A Spanish study shows that women who seek the sun have one-eleventh the hip-fracture risk as those who avoid sun.
    •Men who work outdoors have half the risk of melanoma as those who work indoors.
    •Women who avoid the sun have 10-times the risk of breast cancer as those who embrace the sun.
    •Women who sunbathe regularly have half the risk of death during a 20-year period compared to those who stay indoors.
    •Sun exposure increases nitric oxide production, which leads to a decrease in heart attack risk.
    •Vitamin D, the sunshine vitamin, is essential to human survival, and sun exposure is the only natural way to obtain it
    •Sun exposure dramatically improves mood through the production of serotonin and endorphin.
    • Sun exposure increases the production of BDNF, which is vital to human health.
    Sunscreen reduces all of these healthful effects by preventing sun exposure. Think about it!
    For references and articles,


      Moderation, as with all things, is the keyword here. You are speaking of extremes on both sides of the issue. You need food to survive, but too much can be unhealthy and the same can be said for sunlight.

      People in the tanning bed industry have a particularly big dog in this issue, so their information will be suspect from the beginning. Common sense should prevail.

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