Let the Sunshine In.

With spring temperatures climbing higher, and with summer around the corner, I figure this is a good time to remind people about sun exposure, and using sunscreen. Too much sun exposure – or the use of tanning booths – is a risk factor for melanoma (one of the deadliest cancers) and of squamous cell carcinoma. This is especially true when one gets a sunburn. I forget where I read this statistic, but a sunburn doubles one’s risk of skin cancer (though before getting too panicky, it could mean going from a  1% chance to a 2% chance. Or 5% to 10%. I don’t want to quote exact numbers since I don’t have them handy and it probably also depends on how easily one gets a sunburn, location, skin tones, etc). This increase in risk is why I think doctors tend to encourage taking vitamin D supplements rather than suggesting sun exposure to get enough vitamin D.

However there are other reasons for getting some sunlight as one uses precautions to prevent sun burns:

  1. There might be other benefits to getting sun beyond its effects on vitamin D levels. Believe it or not it might help with blood pressure!! I’ll put a link at the end of this post.
  2. It might have effects on preventing other diseases as well, though it might be due to improved vitamin D levels and not some other effect light has on health.
  3. Getting outside and exercising can improve health (though any exercise, even if done indoors, such as exercising in a gym works too).

However to reduce the risk of skin cancer, there are several things one can do to minimize the risk:

  • Use Sunscreen, at least SPF 15. And reapply if you’ve gone swimming, sweated a lot or if it’s been a few hours since you last applied sunscreen.
  •  Use wide brimmed hats as much as possible. Baseball caps don’t cover your necks or the back of your neck.
  • Get sun early in the day, or later in the afternoon. In other words, don’t go out to get sun when the sunlight is at it’s strongest.
  • Remember, even if you’re only in the sun for 15 minutes, you can get sun damage so sunscreen is important even if you’ll be in the sun for short periods
  • wear long sleeves and long pants if possible.


Anyhow, Here is the link, and a couple of references for those who want to dig deeper into this topic.

Could the sun be good for your heart?


Fernandes, M. R., & Barreto, W. D. R. (2017). Association between physical activity and vitamin D: A narrative literature review. Rev Assoc Med Bras (1992), 63(6), 550-556. doi:10.1590/1806-9282.63.06.550
Fleury, N., Geldenhuys, S., & Gorman, S. (2016). Sun Exposure and Its Effects on Human Health: Mechanisms through Which Sun Exposure Could Reduce the Risk of Developing Obesity and Cardiometabolic Dysfunction. Int J Environ Res Public Health, 13(10). doi:10.3390/ijerph13100999
Hoel, D. G., Berwick, M., de Gruijl, F. R., & Holick, M. F. (2016). The risks and benefits of sun exposure 2016. Dermatoendocrinol, 8(1), e1248325. doi:10.1080/19381980.2016.1248325
Langer-Gould, A., Lucas, R., Xiang, A. H., Chen, L. H., Wu, J., Gonzalez, E., . . . Barcellos, L. F. (2018). MS Sunshine Study: Sun Exposure But Not Vitamin D Is Associated with Multiple Sclerosis Risk in Blacks and Hispanics. Nutrients, 10(3). doi:10.3390/nu10030268
Rivas, M., Rojas, E., Araya, M. C., & Calaf, G. M. (2015). Ultraviolet light exposure, skin cancer risk and vitamin D production. Oncol Lett, 10(4), 2259-2264. doi:10.3892/ol.2015.3519
Santos Araújo, E. P. D., Queiroz, D. J. M., Neves, J. P. R., Lacerda, L. M., Gonçalves, M. D. C. R., & Carvalho, A. T. (2017). Prevalence of hypovitaminosis D and associated factors in adolescent students of a capital of northeastern Brazil. Nutr Hosp, 34(5), 1416-1423. doi:10.20960/nh.1097
Weller, R. B. (2016). Sunlight Has Cardiovascular Benefits Independently of Vitamin D. Blood Purif, 41(1-3), 130-134. doi:10.1159/000441266

Should doctors be environmentalists/advocates for the environment?

One thing that sometimes crosses my mind is whether physicians and other health care workers should also be environmentalists. After all the environment does play a role in people’s health. Contaminated water lead to outbreaks of water born diseases (John Snow, a London physician in the mid 1800’s is credited [at least in part] for ending a Cholera outbreak  by convince authorities to block use of a water pump at the center of the outbreak).  The cholera outbreak following the earthquake in Haiti several years ago is another example. Polluted air leads to increased respiratory disease.

Though in the U.S. and other developed nations with functioning governments, the chances of contaminating water with sewage is low. The one exception could be when severe weather overloads the septic systems in an area. However even in the Northeast U.S. where I live, beaches are monitored for coliform bacteria (this is a generic term for bacteria that live in our guts) and closed when the counts are too high.

Air quality effects health of populations – there were reduced hospitalizations in parts of Ireland after there were bans placed on burning coal.  When lead was taken out of gas (well, actually prevented from being put in gasoline…), blood levels of lead dropped. It’s a neurotoxin and high blood levels can affect brain development in children (hence the ban of lead in paint in the U.S.), and function in adults. For water, it’s not just bacterial contamination/pollution that is important. Chemical pollution can also affect health. Toxins can build up in the food chain – this is part of the reason why it’s suggested that pregnant women limit their intake of certain fish, for example. Mercury builds up in fish at the top of the food chain, such as in Tuna, and can adversely affect people neurologically and adversely affect developing brains. Studies continue to show an association between air pollution and respiratory  deaths.

Given the number of of medications that are derived in whole or part from the plant and animal world (aspirin, reserpine, taxol, digoxin, penicillin, streptomycin, are all plant and fungal products), an argument could be made that making sure plant and animal species don’t become extinct because it might affect future drug discovery. Before you say “but wait,….” think of this: heparin is derived from the linings of Pigs. ACE inhibitors were discovered through research on snake venom. There are some newer medications for Type 2 Diabetes which are derived/grew out of research on saliva from a lizard known as the Gila monster.