Sun 'cuts prostate cancer risk'

Roman Bystrianyk · medicine forum Guru Joined: 02 May 2005 Posts: 454

"Sun 'cuts prostate cancer risk'", BBC News, June 19, 2005,
Link: http://news.bbc.co.uk/2/hi/health/4090972.stm

Sunlight can reduce a man's risk of prostate cancer, a study suggests.

Researchers from three US centres found men exposed to a high amount of
sun had half the risk of the disease than those exposed to a low
amount.

Writing in Cancer Research, they suggest that the protection was a
result of the body's manufacture of vitamin D after sun exposure.

But men were warned not to sunbathe excessively because of the risk of
developing skin cancer.

Vitamin D is also found in foods such as oily fish.

Experts from the Northern California Cancer Center, the Keck School of
Medicine of the University of Southern California, and the
Comprehensive Cancer Center of Wake Forest University all worked on the
study.

They looked at 450 white patients aged 40 to 79 with advance prostate
cancer, from San Francisco.

They compared them with a group of 455 men of similar ages and
backgrounds who did not have prostate cancer.

The men were all asked whether their jobs had involved working outside,
and if so, how regularly they did this.

The scientists also looked at the difference between pigmentation in
underarm skin which is usually not exposed to sunlight, and forehead
skin, which is.

To do this, they used a portable reflectometer - a device which
measures skin tone by emitting light and assessing the amount that is
reflected back, giving a reading on the colour of the skin from 0 to
100.

The difference in scores taken from underarms and foreheads provided an
indication of how much exposure to the sun men had experienced.

The risk of prostate cancer was found to be halved in men who had the
highest amount of sun exposure - an average of 20 hours a week, or
more.

Gene variants

Previous research has shown that the prostate uses vitamin D to promote
the normal growth of prostate cells and to inhibit the invasiveness and
spread of cancer cells to other parts of the body.

Genes determine how the body processes vitamin D. They control
receptors which vary in their ability to bind to the vitamin and
therefore influence the behaviour of cells.

DNA tests carried out by the researchers showed the risk of prostate
cancer was reduced by up to 65% in men with certain gene variants.

Dr Esther John, of the Northern California Cancer Centre, who led the
research, said: "We believe that sunlight helps to reduce the risk of
prostate cancer because the body manufactures the active form of
vitamin D from exposure to sunlight."

She added that if future studies continued to suggest this link,
increasing vitamin D intake from food and supplements might be the
safest solution to achieve the right levels.

Chris Hiley, head of policy and research at the Prostate Cancer
Charity, warned that while increased exposure to sunlight might
decrease the risk of prostate cancer, it also increased the risk of
skin cancer.

"Men need more evidence-based research to know how to balance the risks
and benefits."

Henry Scowcroft, of Cancer Research UK, also cautioned that more work
was needed to weigh up the risks involved.

"For most people, it usually takes just a few minutes of sun exposure
for your skin to make a very large amount of vitamin D," he added.

Coilman · medicine forum beginner Joined: 15 May 2005 Posts: 3

"Roman Bystrianyk" <rbystrianyk@gmail.com> wrote in message
news:1119221477.184668.205890@g47g2000cwa.googlegroups.com...

Roman Bystrianyk · medicine forum Guru Joined: 02 May 2005 Posts: 454

Some more information for your consideration. Enjoy your day.

http://www.healthsentinel.com/org_news.php?id=032&title=Sun+Exposure+Increases+Survival+from+Melanoma&event=org_news_print_list_item

Roman Bystrianyk, "Sun Exposure Increases Survival from Melanoma",
Health Sentinel, March 8, 2005,

According to the Mayo Clinic, skin cancer is the most common cancer in
the United States. The incidence of skin cancers has been increasing
for the last 50 years in all developed countries. Mortality from skin
cancers has also been increasing, although not as greatly as the
incidence. All forms of skin cancer have been on the rise. More benign
forms include basal cell and squamous cell carcinomas. However, the
greatest rise has been in melanoma, which is the most serious and most
deadly type of skin cancer. The percentage of people with melanoma has
more than doubled over the last 30 years.

Because of the consistent findings that intermittent sun exposure is
associated with an increased risk for melanoma, public health officials
have recommended that excessive sun exposure should be avoided.
Recommendations generally include avoiding sun exposure and use of
sunscreens throughout the year.

A recent study in the Journal of the National Cancer Institute
contradicts this advice. The study looked at 528 melanoma patients who
were entered in the Connecticut Tumor Registry. They examined a number
of factors to determine the risks related to death from melanoma.

They found that sunburn, high intermittent sun exposure, solar
elastosis, which is a marker of sun damage, and self-reported skin
awareness were all linked to improved survival from melanoma. "Sun
exposure was statistically significantly inversely associated with risk
of death from melanoma, regardless of the measure used. Individuals who
has ever been severely burned or who has high levels of intermittent
sun exposure were less likely to die from melanoma than individuals who
had never been severely sunburned or who had low levels of intermittent
sun exposure respectively."

The authors also found that, "recent sunscreen use nor childhood
sunscreen use were statistically associated with the risk of death from
melanoma." They did find that individuals who paid attention to their
skin have a lower risk of death from melanoma, however, "reported
skin self-examination and physician skin examination were not
significantly associated with the risk of death from melanoma."

Attempting to explain their findings the authors note that sun exposure
is essential for the skin to make vitamin D3. Vitamin D has been shown
to be anticancer in nature and therefore could explain the beneficial
association between sun exposure and survival from melanoma. Another
possibility put forward is that sun exposure induces less aggressive
melanoma by increasing the DNA repair capacity and thus reducing
further more deadly changes in melanoma.

The authors conclude that, "we found that intermittent sun exposure
may increase survival from melanoma. If these results are confirmed,
our findings have the potential to lead to interventions, such as
stimulation of the vitamin D pathway or DNA repair capacity, that would
increase survival from melanoma and, perhaps, from other cancers."

SOURCE: Journal of the National Cancer Institute, February 2, 2005

Guest

Too bad the researchers did not test for the influence of sunshine on
the male genetalia and the male sex drive. If they had, they would
have found that the level of testosterone would have increased by
around 50% and the male libido would have increased the same.

Who needs Viagra. Give me the sun.

DrC PhD

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