Sunlight Can Reduce Cancer Risks

Study Finds Link Between UV Exposure and Cancer
A study that correlated exposure to sunlight with cancer risk found that people exposed to more sunlight had a significantly lower risk of many types of cancer.  The study drew from the National Institutes of Health-AARP (NIH-AARP) cohort of 450,934 white, non-Hispanic subjects aged 50-71 years from diverse geographic areas in the US. 

During up to nine years of follow-up to the end of 2006, 75,917 cases of cancer were identified.  Researchers correlated the calculated ultraviolet radiation (UVR) exposure in these different areas with the incidence of a variety of cancers. The diverse sites included six states (California, Florida, Louisiana, New Jersey, Pennsylvania, and North Carolina), and the metropolitan areas of Atlanta and Detroit. They followed these subjects over a period of nine years in the study and eliminated other known risk factors for cancer such as smoking, body mass index, and physical activity. This was the first prospective study (participants were actively observed for the duration of the study) to look at the relationship of sunlight to cancer.

Difference in Men and Women

A total of 75,000 participants in the study contracted cancer. The study found that 12 types of cancer were reduced in those subjects exposed to more sunlight. These included cancers of the lungs, prostate, pancreas, colon, thyroid and many other types. As expected melanoma and other skin cancers occurred more often in the participants exposed to more sunlight. The incidence of cancers of female organs including the ovaries, breast, and uterus were not reduced in this study.  This led the researchers to speculate that women may spend less time in the sun than men.  That has yet to be confirmed by further research, however.  The study did confirm a previous study that showed a decreased incidence of cancer in men but not women in relation to sun exposure.

Vitamin D is Protective
This research confirms the protective effect of Vitamin D for many types of cancer. No other known factors in sun exposure would account for these findings. This provides more evidence that sun exposure is protective and that the routine use of sunscreens is counterproductive. Sunscreen should be used to prevent sunburn during prolonged exposure to bright sun at midday. Otherwise sun exposure and ultraviolet radiation promote health. Similarly, in parts of the world and times of the year with limited sun exposure taking a vitamin D supplement in adequate amounts is beneficial to the immune system, promotes bone growth, prevents cardiovascular disease, and reduces the incidence of cancer.

Go Outside
So now researchers have found another reason to get your kids (and yourself) outside.  The intensity of the midday sun warrants sun screen but after that leave it off and soak up some vitamin D.  We know that vitamin D deficiency is linked to higher rates of many forms of cancer‚ as well as heart disease‚ osteoporosis‚ multiple sclerosis and many other conditions and diseases. 

Humans make 90 percent of our vitamin D naturally from sunlight exposure to our skin – specifically, from ultraviolet B exposure to the skin, which naturally initiates the conversion of cholesterol in the skin to vitamin D3. 
Sunlight is the best and only natural source of vitamin D. Unlike dietary or supplementary vitamin D, when you get your ‘D’ from sunshine your body takes what it needs, and de-metabolizes any extra. That’s critical – as vitamin D experts and many health groups now advocate 1,000 to 2,000 IU of vitamin D daily – five to ten times the old recommendations. Because too much ‘D’ from dietary supplements may cause the body to over-process calcium, nobody really knows for sure how much supplementary vitamin D is safe. On the other hand, sunlight-induced vitamin D doesn’t have that problem – it’s the way your body is intended to make it!

Sunlight Exposure (full body exposure)*	3,000 – 20,000 IU
Salmon (3.5 oz. of fresh, wild salmon)	600 – 1,000 IU
Salmon (3.5 oz. of fresh, farmed salmon)	100 – 250 IU
Fortified Whole Milk, 8-oz. glass**	100 IU
Fortified Multi-vitamin	400 IU

* Sun exposure to the arms and legs for 10-15 minutes. The amount of vitamin D produced depends on the intensity of the UVB in the sun and many other factors. Darker-skinned individuals may need 5-10 times more exposure than a fair-skinned person to make the same amount of vitamin D. In northern climates sunlight is too weak in parts of the year to make any vitamin D – a period referred to as ‘Vitamin D Winter’.


Sources:
Dr. Randall Neustaedter, OMD www.cure-guide.com

http://blog.vitamindcouncil.org/2012/05/02/is-uv-radiation-exposure-correlated-with-cancer/

Grant WB. An ecological study of cancer mortality rates in California, 1950-64, with respect to solar UVB and smoking indices. Dermatoendocrinol., epub April 2012.

Lin SW, Wheeler DC, Park Y, Cahoon EK, Hollenbeck AR, Michal Freedman D, Abnet CC. Prospective study of ultraviolet radiation exposure and risk of cancer in the U.S. Int J Cancer. 2012 Apr 26. doi: 10.1002/ijc.27619

http://www.landesbioscience.com/journals/dermatoendocrinology/article/19834/

http://www.sunshinevitamin.org/

Holick, MF. Vitamin D Deficiency. New England Journal of Medicine, July 2007