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What are the long-term consequences of a lifetime of sun avoidance?

Posted on: May 30, 2018   by  John Cannell, MD


We all know – and if we forget, the dermatologists remind us – that one’s lifetime sun exposure is associated with skin cancer. Scientists have confirmed this finding many times. Dermatologists forget to clarify that many studies show the most feared form of skin cancer, malignant melanoma, is not associated with cumulative sun exposure. Sun phobia is an ubiquitous concern, pervasive, even among teenagers: “Let’s go to the beach?” “No, I don’t want to get skin cancer.” What does this mean for these kids’ future?

The long-term health implications of sun avoidance


One risk is those who avoid the sun most of their lives have about a 40% greater risk of getting dementia as they age. This finding was just published but has been reported before. While non-melanoma skin cancers are usually just a nuisance (having to get them frozen), few people think dementia is just a nuisance. You will not see the Surgeon General or the dermatologists publicize this dementia and sun avoidance study; they will continue to encourage a behavior that increases a widely feared disease.

Breast cancer

Another non-nuisance disease is breast cancer. Women who avoid the sun have a much greater risk of developing breast cancer. In an analysis of women in the National Health and Nutrition Examination Survey Epidemiologic Study, researchers found that the protective effects of sun-exposure on breast cancer was simply enormous. The risk reductions were highest for women who lived in United States regions of high solar radiation, with RRs ranging from 0.35-0.75. That means, sun-exposure reduced the risk of breast cancer by three-fold; for every 100 breast cancers in women practicing sun avoidance, the sun-loving women only had about 35 cancers, an enormous reduction.

Bone fractures

What else can you look forward to if you avoid the sun? How about hip fractures? Yes, it turns out that cumulative sun exposure, as measured by sun damaged skin, decreases one’s risk of breaking a hip. It’s not just hip fractures, but the prevalence of other fractures is lower in those with high lifetime sun exposure. About 400,000 Americans fracture a hip every year and about 20% of them will be dead in a year. So, compare deaths in the US from non-melanoma skin cancer (about 1,500/year) to deaths from hip fracture (70,000).

Multiple Sclerosis

My personal favorite is how  dermatologists avoid talking about multiple sclerosis (MS). Dozens of studies show both lifetime sun exposure and current sun exposure (whether you go to the beach this weekend) reduce the risk of eventually contracting MS. This is a disease you do not want to get. Just recently, scientists confirmed this link between sun avoidance and MS.


Have you ever wondered how persons with myopia (near-sightedness) got along before eye glasses? Wouldn’t saber tooth tigers have quickly eaten them? It turns out that developing myopia in childhood is a recent phenomenon. Evidence is mounting that the incidence of myopia is growing around the world, with a recent study estimating that on average, 30% of the world is currently myopic and by 2050, based on current trends, 50% will be myopic, that’s a staggering 5 billion people. Guess what, according to the best scientific findings available, children who get a lot of sun-exposure have a much-reduced risk of developing myopia.


The definitive study on the long-term effects of sun avoidance followed more than 29,000 Swedish women for up to 20 years. Before following the women, scientists classified the women as “sun lovers” or “sun avoiders.”  The sun avoiders died much younger than the sun lovers, and the size of the sun-avoidance effect of sun avoidance is equivalent to the risk of smoking.

So, the government spends bundles on anti-smoking campaigns, but then spends bundles on anti-sun messages, in effect canceling  any positive outcomes of the anti-smoking message with their deadly advice to avoid the sun.


John Cannell, MD. What are the long-term consequences of a lifetime of sun avoidance? The Vitamin D Council Blog & Newsletter, 5/2018.

6 Responses to What are the long-term consequences of a lifetime of sun avoidance?

  1. Ian Hodgson

    May I have permission to reprint your article in the main NZ newspaper The Herald? This summary is so important for all people in NZ to consider and act upon. Sun avoidance is becoming so extensive.
    Ian Hodgson PhD

  2. nigelcooper41433400

    Indebted to the good Doctor for his researches and guidance in this vital subject. As someone that has hidden from the sun for over 20 years because of the risk of skin cancer I am now reaping the rewards I suspect with Parkinsons and CFS/ME being in part if not all due to a low level of Vitamin D over many years. Supplementation and careful exposure to UVB is hopefully now making a difference – time will tell!
    A vast subject that needs promulgating at every opportunity, indeed IMHO if we all did the right amount of ‘sun worshipping’ the state of this countries health would change almost overnight.
    Good luck Doctor and keep up the excellent work.

  3. John Cannell, MD

    Yes, by all means

  4. sdixon153

    Question: I am Fitzpatrick skin type 1 (ivory skin, hazel eyes, sun reaction: skin always freckles, always burns and peels, and never tans). As a dumb teenager, I overexposed myself. Fortunately I wised up eventually and started using sun protection in my late 20s. Now 50 years old, loads of age spots, permanently pinkish skin on neck and chest. I burn going to the mailbox in February at the 45th parallel (not joking). Even the most minute bit of sun exposure turns me pink. I take 4000 IU vitamin D per day. Blood Vit D is low end of normal. I avoid the sun like a vampire – always use physical block 50 SPF, year round, and cover most areas with sun blocking clothes as much as possible. I’m reluctant to change this behavior. I work in oncology and have seen far too many melanoma (and other) skin cancers to be comfortable with willingly exposing myself to sun when even 5 minutes makes me burn.

  5. fredglass

    Reply to sdixon: Your comment confirms to me how variable we all are in our biology. I have the average skin type and don’t think I could sunburn if I tried.

    Was just wondering if you increased your Vit D level if it would ameliorate your extreme sensitivity. I know the experts say vitamin D from supplements or the sun are the same but I can vouch with certainty at least for myself that they have distinctly different effects. I’d be curious to know if experimenting with higher D supplements using the Bio Tech cofactors, say between 5K – 10k i.u.. would reduce some of your sensitivity. [email protected]

  6. lgavlock

    Interesting article. My father has been in a nursing home for the last 8 years with very little outdoor exposure… no outdoor exposure in the last 2 years. I often wonder if anyone ever tests the vitamin D levels of residents living this way and if supplementing would help many of them.

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