To prevent cancer, everyone should bare off and take the noon-day sun for several minutes every day
However, not so long that you burn (or even turn pink), and also go out WITHOUT a hat, sunblock, glasses or sunglasses
Risk of developing several cancers increases with the latitude of where you live (i.e. the less sun you get in your location, the higher your risk for cancer). Including Hodgkin's lymphoma, colon, pancreatic, prostate, ovarian, and breast cancer.
Maintaining a sufficiency of vitamin D in your blood protects against several common cancers. Several large cohort studies have now shown that 25(OH)D (CALCIDIOL, precursor to active vitamin D) levels<20 ng/mL (50 nmol/L) are associated with a 30 - 50% higher risk of colon, prostate, and breast cancer. A recent review of vitamin D in the prevention of colorectal cancer concluded that a CALCIDIOL level of 36 ng/mL (90 nmol/L) provided optimal protection against the development of colorectal neoplasia
Bischoff-Ferrari HA, Giovannucci E, Willett WC, Dietrich T, Dawson-Hughes B. Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes. Am J Clin Nutr. 2006;84:18-28.
Vitamin D deficiency linked to cancer back in the 1930's - A study of US navy personnel linking internal cancers with a lack of exposure to the sun / vitamin D deficiency was published in 1937. Since then several studies (referenced further in this article) have shown a lower risk for cancer for those living in sunnier states, at higher latitudes (with higher UV-B availability), and in rural areas (where people tend to spend more time outdoors). Attempts have been made to explain these geographic benefits as differences in other lifestyle factors, such as diet and socioeconomic status, however, the two main risk factors for cancer, i.e. smoking and diet, are not significantly different across the country.
CALCITRIOL (the active form of vitamin D)regulates cell growth and maturation. Exposing the skin to the sun's UV-B radiation produces vitamin D in the body, and it has been consistently demonstrated that activation of the vitamin D receptor by CALCITRIOL reduces cancer risk via fairly well defined mechanisms, which prevent cells from becoming malignant:
Mantell DJ et al, 1α,25-dihydroxyvitamin D3 inhibits angiogenesis in vitro and in vivo, Circ Res 2000; 87:214-220][van den Bemd and Chang, 2002;
Giovannucci E. The epidemiology of vitamin D and cancer incidence and mortality: a review (United States). Cancer Causes Control 2005;16:83-95]. CrossRef Medline Web of Science
Lamprecht and Lipkin, 2003
The cancers most strongly linked to low levels of VITAMIN D are:
Increased vitamin D3 levels could prevent 250,000 cases of colorectal cancer and 350,000 cases of breast cancer worldwide each year. According to researchers from the Moores Cancer Center at the University of California, San Diego (UCSD), especially in countries north of the equator (150,000 cancer cases in the U.S. could be prevented). Protective effects began when blood CALCIDIOL (25(OH)D) levels ranged from 24 -32 ng/ml. In the U.S., late winter 25(OH)D levels ranged from only 15 - 18 ng/ml. Previous research has shown optimal cancer prevention value to be ~55 ng/ml.
Researchers concluded that an Intake of 2000 IU/day of Vitamin D3, and very moderate exposure to sunlight (when possible), could raise serum 25(OH)D to 52 ng/ml -a level associated with a 50% reduction in breast cancer incidence, according to observational studies.
The Journal of Steroid Biochemistry and Molecular Biology March 2007; 103(3-5):708-11
U.S. study found 16 types of cancer (primarily epithelial, relating to surface) cancers of the digestive and reproductive systems to be inversely correlated to UVB exposure. These cancers included breast, endometrial, esophageal, ovarian, non-Hodgkin's lymphoma, prostate, bladder, gallbladder, gastric, pancreatic, rectal and renal cancers;
In males approximately 80% of the cancers attributable to low regional solar UV-B were digestive-system cancers
Other cancer correlations. 10 types of cancer were significantly correlated with smoking, 6 types with alcohol, and 7 types with Hispanic heritage. Poverty status was inversely correlated with 7 types of cancer. Since the results for alcohol, Hispanic heritage, and smoking for white Americans agree well with the literature (Trapido et al., 1995; Thun et al., 2002),they provide a high level of confidence in the study's approach and results for UVB radiation
Grant WB. An estimate of premature cancer mortality in the U.S. due to inadequate doses of solar ultraviolet-B radiation.Cancer 2002 94 1867-75.
Averaged annual solar radiation inversely correlated to mortality from digestive cancers (but not other cancers) in Japan. - i.e. Esophagus, stomach, colon, rectum, pancreas, and gallbladder and bile ducts - It is interesting that UV-B exposure makes a difference, since Japan's high fish consumption, would ensure high levels of dietary vitamin D;
A Norwegian study shows that breast, colon, and prostate cancer detection has a seasonal cycle correlated with vitamin D production by sunlight -the study also shows that vitamin D effectively fights cancer even in the later stages.
Robsahm TE, et al, Vitamin D(3) from sunlight may improve the prognosis of breast-, colon- and prostate cancer (Norway). Cancer Causes Control. 2004;15:149-58
Low exposure to UV-B increased the risk of endometrial cancer in one study
Preventive Medicine February 4, 2007
More sunlight reduces colon cancer mortality. The key to understanding this geographic pattern was provided by Cedric and Frank Garland in 1980. They reasoned that sunlight, through the production of vitamin D, reduced the risk of colon cancer in the sunny areas compared to that in the darker areas. They performed an ecologic study of annual solar irradiance versus colon cancer mortality rates and found a strong inverse correlation, i.e. the more sunlight, the less cancer. (An ecologic study treats entire populations defined geographically as entities, with values for disease outcome and environmental or dietary factors averaged for each entity.)
Garland CF, Garland FC. Do sunlight and vitamin D reduce the likelihood of colon cancer? Int J Epidemiol. 1980;9:227-31.
In 1941, Dr. Frank Apperly demonstrated an association between latitude and cancer mortality
Apperly FL. The relation of solar radiation to cancer mortality in North American. Cancer Res 1941;1:191-5
U.S. cancer mortality rates higher in Northeast than Southwest. An explanation involving environmental factors is required to explain why mortality rates for a number of internal cancers are ~ twice as high in northeast's highly-urbanized states than in the southwest's more rural states.
Devesa SS, Grauman DJ, Blot WJ, Pennello GA, Hoover RN, Fraumeni JF Jr., Atlas of Cancer Mortality in the United States, 1950-1994. NIH Publication No. 99-4564, 1999.
Smoking and diet are known risk factors for cancer neither of which vary significantly throughout mainland U.S.
Doll R, Peto R. The causes of cancer: quantitative estimates of avoidable risks of cancer in the United States today. J Natl Cancer Inst. 1981;66:1191-308.
Lifetime exposure to sunlight may reduce your risk of some of the most common types of cancer. In an analysis of death certificates from 24 U.S. states between 1984 and 1995, National Cancer Institute (NCI) researchers found that people who lived in the sunniest parts of the country, and those exposed to the most sunlight through their jobs, had significantly lower rates of breast and colon cancer than matched controls.They only included people who were born and died in states in the same solar radiation range. Overall, people who lived in the highest solar radiation range (E.g. in Arizona, Hawaii, Florida, and Texas) had less risk of dying of breast, ovarian, prostate, or colon cancer than those who lived in the lowest range (E.g. in Maine, New Hampshire, Ohio, and Washington).
People who worked outside had 20-25 % less risk of breast and colon cancer. Across all levels of solar radiation and even after adjusting for physical activity level.
Study found that rural residence was inversely correlated to breast, colon, endometrial, esophageal, ovarian, and non-Hodgkin's lymphoma. This suggests that urban living is associated with reduced UVB exposure compared to living in a rural environment. The study estimated 45,000 Americans die from cancer annually as a result of inadequate vitamin D levels. Of these, 22,500 urban Americans die as a consequence of indoor lifestyle and lack of exposure to the sun's UVB light, and another 22,500 based on residential location due to unavailability of UVB.
Grant WB. An estimate of premature cancer mortality in the U.S. due to inadequate doses of solar ultraviolet-B radiation. Cancer 2002;94:1867-75
Don't "buy" into the lie that sun exposure is the main cause of skin cancer
As early as 1937, Peller and Stephenson hypothesized that sunlight exposure lowered the risk of cancer. A study of US navy personnel linked those with skin cancer and actinic keratosis with lower risk for internal cancers
Peller S, Stephenson CS. Skin irritation and cancer in the United States Navy. Am J Med Sci 937;194:326-33. CrossRefWeb of Science
The campaign to discourage sun exposure and urge the use of sun block began about 30 years ago when dermatologists noticed that skin cancer rates were increasing, and wrongly assumed that excess sun was causing this increase. In the 90's, already aware that lack of sun/vitamin D could cause rickets, scientists began to realize that vitamin D had multiple roles in all the body's cells, and suspected that lack of vitamin D was increasing certain cancer rates, including breast and colon cancer.
Two studies run by the Harvard School of Public Health found that high vitamin D levels reduced risk for colon cancer. The Nurse's Health Study and the Health Professionals Study (1986-2006), have been following tens ofthousands of people for decades:
Chronic (repeated) sunburn on skin containing free radicals, and not sun-tanning, leads to skin cancer.
Melanoma rates have increased right along with sun avoidance and increased use of sunscreens. Most melanomas occur on areas least exposed to sun. Two reports suggest that moderate sun exposure decreases risk of melanoma
Kennedy C et al, The influence of painful sunburns and lifetime of sun exposure on actinic keratoses, seborrheic warts, memlanocytic nevi, atypical nevi and skin cancer, J Invest Derm 2003;
Garland FC, Garland CF, Occupational sunlight exposure and melanoma in the US Navy, Arch Env Health,1990, 45:261-267;
Those who are regularly exposed to UV radiation in their occupation have a reduced risk of developing melanoma. This was mainly attributed to these two factors:
Garland FC, Garland cf, Occupational sunlight exposure and melanoma in the US Navy, Arch Env Health,1990, 45:261-267
Kennedy C et al, The influence of painful sunburns and lifetime of sun exposure on actinic keratoses, seborrheic warts, memlanocytic nevi, atypical nevi and skin cancer, J Invest Derm 2003;
Excessive exposure to sunlight increases non-melanoma cancers
Kennedy C et al, The influence of painful sunburns and lifetime of sun exposure on actinic keratoses, seborrheic warts, memlanocytic nevi, atypical nevi and skin cancer, J Invest Derm 2003
In children and young adults, moderate sun exposure is associated with a 40% reduced risk of developing non-Hodgkin's lymphoma and decreased mortality if they developed melanoma
ChangET,SmedbyKE, HjalgrimH, Porwit-MacDonaldA, RoosG, Glimelius B, Adami HO. Family history of hematopoietic malignancy and risk of lymphoma. J Natl Cancer Inst. 2005;97:1466-74
Berwick M, Armstrong BK, Ben-Porat L, Fine J, Kricker A, Eberle C, Barnhill R. Sun exposure and mortality from melanoma. J Natl Cancer Inst. 2005;97:195-9.
A study of 497 people with melanoma in and around Philadelphia and San Francisco supported these two factors:
Amy E. Millen, Margaret A. Tucker, Patricia Hartge, Allan Halpern, David E. Elder, DuPont Guerry IV, Elizabeth A. Holly, Richard W. Sagebiel , Nancy Potischman, Cancer Epidemiol Biomarkers Prev June 2004 13; 1042
Tobacco and marijuana smokers who expose themselves to sunlight tend to get skin cancer. According to Dr. Michael Gray;
Cancer is common in those who over-consume coffee and teas (which contain toxic caffeine and tannic acid) and expose themselves to sunlight. Wrote Dr. Becker and D. Alexander;
Immuno-suppressant drugs may contribute to skin cancer as well as x-rays and chemotherapy
In the early 1940s, Frank Apperley, M.D. wrote that sun exposure could promote immunity against cancer:
"We may be able to reduce our cancer deaths by inducing a partial or complete immunity by exposure of suitable skin areas to sunlight"
CALCITRIOL found to be especially affective against breast, colon, skin, ovarian and prostate cancer. In addition to the kidneys, it is believed that many cells can make CALCITRIOL (the active form of vitamin D) from CALCIDIOL (the inactive, main circulating form of D) -E.g. colon, prostate, breast and lung cell cultures have recently been found to express 1-OHase (the enzyme required to produce CALCITRIOL from circulating CALCIDIOL);
Sunlight stabilized or improved tumors in small 1959 study. Jane C Wright, directing cancer research at Bellevue Memorial Medical Center in New York City, was fascinated by the light ideas of John Ott DSc. Advised by Ott, Dr Wright instructed fifteen cancer patients to stay outdoors as much as possible that summer in natural sunlight without wearing their glasses, and particularly without sunglasses. By fall, the tumours in 14 of 15 patients had not grown, and some patients had improved. Ott wondered why the 15th person had not benefited. He discovered that this woman had not fully understood the instructions - while she had not worn sunglasses, she had continued to wear her prescription glasses. This blocking of UV into her eyes was enough to stop the benefits enjoyed by the other fourteen.
Sunbathing helped heal the skin cancer of Dr. Harland G. Call. His skin cancer was diagnosed by two M.D.s, one of whom was a surgeon who recommended surgical removal. Call sunbathed the affected area and within a short time, the skin cancer disappeared. He reported back to the M.D. who had recommended surgical removal. When the M.D. examined him, he confirmed that the skin cancer had disappeared without surgical removal.
A man had recurrent skin cancer - His doctor recommended surgery . . . Rejecting the surgery, the man instead followed the advice of Dr. John Ott to sunbathe without his glasses and after five months his skin cancer completely disappeared.
Prostate cancer has been found to be inversely correlated to geographic availability of sunlight and skin darkness.
Researchers, at Northern California Cancer Center found that men with high sun exposure had half the risk of prostate cancer than did men with low sun exposure
2005 (Jun 15th) issue of Cancer Research
Vitamin D at mid-range levels is growth inhibitory to prostate cells
Tuohimaa P. et al, Both high and low levels of blood vitamin D are associated with a higher prostate cancer risk
Some studies suggest that higher circulating CALCITRIOL may be more important than CALCIDIOL for protection against aggressive, poorly-differentiated prostate cancer. Unlike colorectal tumors, prostate cancers lose the ability to hydroxylate CALCIDIOL to CALCITRIOL, and thus may rely on the circulation as the main source of CALCITRIOL. Suppressing circulating CALCITRIOL levels by calcium intake could explain why higher calcium and milk intakes appear to increase risk of advanced prostate cancer.
The following references were compiled at mercola.com
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Cancer Studies
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•Grant WB, Garland CF. The association of solar ultraviolet B (UVB) with reducing risk of cancer: multifactorial ecologic analysis of geographic variation in age-adjusted cancer mortality rates. Anticancer Res. 2006 Jul-Aug;26(4A):2687-99.
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•Ng K, Meyerhardt JA, Kana Wu, Feskanich D, Hollis BW, Giovannucci EL, Fuchs CS. Circulating 25-hydroxyvitamin D levels and survival in patients with colorectal cancer J Clin Oncol. Jun 20 2008: 2984-2991.
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•Pilz S, Dobnig H, Winklhofer-Roob B, Riedmüller G, Fischer JE, Seelhorst U, Wellnitz B, Boehm BO, März W. Low serum levels of 25-hydroxyvitamin d predict fatal cancer in patients referred to coronary angiography. Cancer Epidemiol Biomarkers Prev. 2008 May;17(5):1228-33.
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