May 18, 2016


Harness the Power of the Sun for Health

Sunshine is good for you! 

It is important to manage your sun exposure with an understanding of:
Sunshine is important for your health, but before you get sun rays you need to assess your current situation. We want to get sunshine and all its beneficial aspects, but we don't want to burn. Serious sun burns, particularly before the age of 20, increase the risk of all types of skin cancer.


What is UV index?

The ultraviolet index or UV index is a measurement of the strength of the sun's ultraviolet rays. It is 0 in the dark of night and 10-11 in the middle of a summer day with no cloud cover. This index was developed by Canadian scientists in 1992. It has now been adopted by the World Health Organization and most government entities as a mechanism to assess the sun's strength and make recommendations on sun exposure.

At first the numbers may seem random, but it is in fact a linear scale. So, if you determine that you are a skin type II and burn in 30 minutes at a UV index of 6, then you will likely burn in 15 minutes at a UV index of 12. 

The UV index is one of the three key factors for managing your sun exposure. You need to know your skin type, which determines your reaction to sun, the UV index, how strong the sun is, and then determine the proper duration to give you a minimal erythemal dose of UV exposure to produce vitamin D and other healthy properties - including nitric oxide - without burning. You just want to get a *smidge* pink the next day.

One of the easiest ways to know the UV index wherever you are is to download the free dminder app on your phone!

Want to understand skin type? Read last week's news.

Mathematical Ramblings from a Vitamin D Scientist

Editorial by
Cedric F. Garland, Dr., PH, FACE
UC San Diego School of Medicine

How should the US best focus its efforts?

Last week there was an article which summarized Richard Weller's position on sunlight - that it is necessary. One of the quotes was that in the UK "deaths from heart disease are a hundred times higher than deaths from skin cancer."

I decided to see if it is true for the US as it is a great statistic to use in our work. Here's what I found using American Cancer Society (ACS) and American Heart Association (AHA) data:
  • 787,000 people die from cardiovascular disease each year in the US. This includes 375,000 from heart disease and other deaths from cerebrovascular disease. (Source: AHA)
  • 10,130 people die from melanoma and 2,000 die from basal or squamous cell skin cancer each year in the US. Sum = 12,130. (Source: ACS)
  • The ratio is 787,000/12,130 = 65. Not quite as high as the 100 that Weller mentioned for the UK, but it still means that skin cancer deaths are only 1.5% of cardiovascular disease deaths, so why not focus on the 98.5% of the total of these, rather than the 1.5%? A ratio of 65 deaths from all cardiovascular disease events combined is still extremely more deaths than those attributed to skin cancer.
  • Since we know that vitamin D from the sun or elsewhere will prevent approximately 80% of cancer (Lappe et al., 2007), we could include cancer deaths in addition to cardiovascular deaths. 582,870 Americans die of cancer other than of melanoma or other skin each year (ACS, 2016 projection).
  • Multiply that by 80% preventable and you get 582,870 X 80% = 466,295 preventable deaths from cancer due to vitamin D deficiency. The ratio is 466,295/12,130 = 38. It's amazing that we are losing 466,295 people to cancer each year due to vitamin D deficiency and no one besides us cares.
  • If we add all cardiovascular deaths and deaths from non-skin cancer, we get 787,000 + 582,870 = 1,369,870 deaths. The ratio of this figure to skin cancer deaths is 1,369,870/12,130 = 113.
So we in the USA have 113 times the number of deaths from cardiovascular disease and non-skin cancer compared to deaths from skin cancer. As a nation, we really do have to quit being so preoccupied with trying to prevent skin cancer. It's costing us thousands of lives each year.

Best wishes,

Research Paper of the Week

Sunlight for Better or for Worse? A Review of Positive and Negative Effects of Sun Exposure

Dr. Han van der Rhee, et al., conducted an extensive review study based on 71 original studies, 21 meta-analyses, 6 systematic reviews and 17 reviews (115 total), by researchers from the Netherlands representing dermatology, public health, and molecular cell biology. The research team reviewed both the positive and negative effects of sun exposure and concluded that both too much and too little sunlight may be harmful to our health.

Overall health benefits of the sun

Multiple meta-analyses have found an inverse association between chronic and occupational exposure and melanoma risk.

Similarly, a systematic review of 26 case-control and 19 cohort studies demonstrated a consistent inverse association between chronic sun exposure and the following cancers: colorectal-, breast-, prostate-, and non-Hodgkin's lymphoma.

A review of epidemiological studies suggest that regular exposure to the sun and a natural exposure to bright light during the day with less light in the evening is inversely associated with the risk of cancers of the colon-, breast-, prostate-, and non-Hodgkin's Lymphoma, as well as multiple sclerosis, and metabolic syndrome (including hypertension and diabetes mellitus).

The biological effects of sunlight

Review table 7 of the paper for more detail on this list of biological effects of sunlight - effects and implications.
  • DNA damage
  • Photoadaptation
  • Epidermal thickening
  • Immunomodulation
  • Vitamin D
  • Nitric oxide
  • Serotonin and endorphins
  • Circadian clocks
  • Melatonin
  • Folic acid
How does the sun make your skin stronger?

Human skin adapts to regular, non-burning, sun exposure with increased melanin (pigment in the skin),a thickening of the stratum corneum (outermost layer of epidermis), and a reduction in cyclobutane pyrimidine dimers (CPD) a substance known to cause overall cell damage. Research on these effects have found that regular exposure to doses of solar-simulating artificial UV for 3 weeks decreases the ultraviolet sensitivity of the skin for erythema (redness) on average by 75%.

Regular exposure to UV, as experienced by outdoor workers and regular sun bathers, leads to an almost complete disappearance of DNA damage in the basal and suprabasal layers of the epidermis, where skin cancer occurs, because it is in these lower levels of skin where the cells are replicating. In contrast, DNA damage in the top layers of the epidermis doesn't have the same consequences because the cells are already committed to cell death.

Key Findings - Why there can't be just one recommendation

The Australian prevention programs of "Slip! Slop! Slap!" (to "slip" on a shirt, "slop" on sunscreen, and "slap" on a hat) and SunSmart established in the 1980s have been adopted and copied by most Western countries. The primary messages of these programs have been avoidance of the mid-day sun, the use of protective clothing, and use of sunscreens with a SPF of 30 or higher that protect against UVA and UVB. Rather than tailor the message to the conditions of individual countries or regions, the same sun exposure advice is used all over the world. While the message is appropriate for persons with sun-sensitive skin living in countries with high ambient UV, such as Australia, it is less applicable in other parts of the world where chronic exposure and outdoor occupations are associated with a relatively low risk of melanoma and basal cell carcinoma and even squamous cell carcinoma.

"Most skin cancers are caused by a mismatch between skin type and geography and/or sun exposure related lifestyle."


"It is obvious that excessive sun exposure and sunburn should be avoided. During sun-seeking vacations an adequate protection is needed. It is, however, unlikely that continuous protection during daily life contributes to our health, particularly in countries with a temperate climate. Both too much and too little sunlight may be harmful to our health."

Editor's Letter
Susan Siljander
Marketing Director, GrassrootsHealth

Enjoy and share this week's Sunny Hippocrates cartoon!

Susan Siljander
Marketing Director, GrassrootsHealth
A Public Health Promotion & Research Organization
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A Vitamin D Deficient White House

President Obama's physical from 2014 noted a vitamin D level of 23 ng/ml - too low! Since that time his doctor had him on "daily vitamin D," though the report doesn't specify how much.
Almost two years later and it is not much better, 26 ng/ml. We have an opportunity to convince the white house about the health benefits of vitamin D within 40-60 ng/ml...

May is...
National Sunshine Month
Harness the Power of the Sun for Health

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The weird history of vitamin D - and what it actually has to do with the sun
Washington Post
May 12, 2016


free app!

tracks vitamin D from the sun


helps you get vitamin D without burning your skin


notifies you to get your sun exposure at the right time of day


Web site


Sunlight for Better or Worse? A Review of Positive and Negative Effects of Sun Exposure
Han van der Rhee, et al.
Department of Dermatology
Erasmus University Medical Center
The Netherlands
May 2016

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