Skin Cancer Linked To Diet And Virus
More Diet Links To Skin Cancer Found
We all want that summer glow that comes from a day at the beach, but taking in
the rays can have long-term implications for our health. Now Dr. Niva Shapira
of Tel Aviv University's School of Health Professions suggests a way to make
fun in the sun safer and it's all in our food. In a study recently published in
Nutrition Reviews, Dr. Shapira has shown that a diet rich in antioxidants and
omega-3 fatty acids, like the diet eaten in Mediterranean regions where
melanoma rates are extremely low, can help protect us from skin cancer.
The sun's rays damage both the skin and the immune system by penetrating the
skin and causing photo-oxidation, she explains, affecting both the cells
themselves and the body's ability to repair any damage. Her prescription is to
"go Greek" with foods such as olive oil, fish, yogurt and colorful fruits and
vegetables to fight the oxidizing effect of the sun, as well as regular
applications of sunscreen and appropriate body coverings such as hats, beach
coverups, and other sportswear. Previous research demonstrated that the sun's
UV rays damage the skin by exciting its molecules and causing them to become
oxidized, says Dr. Shapira. "My theory was that if you prepared the body with
sufficient and relevant antioxidants, damage could be reduced."
For a study at the Baltic Sea, Dr. Shapira and Prof. Bodo Kuklinski of Rostock
University organized two groups. One group was provided a drink high in
antioxidants, while the other enjoyed beverages such as sodas. Those who
hydrated with the antioxidant-rich drink had fifty percent fewer oxidation
products (i.e. MDA) in their blood at the end of the two-week period, which
included five to six hours of exposure to the sun daily. Further studies proved
that these antioxidants, especially carotenoids - fruit and vegetable pigments
like red from tomatoes and watermelons and orange from carrots and pumpkins
that accumulate in the skin where they serve as a first line of protection -
had delayed the phenomenon of skin erythema, which indicates the initiation of
tissue and DNA damage that can lead to skin cancer.
This information is invaluable, especially in light of climate change, notes Dr.
Shapira. As temperature and humidity get stronger, which aggravates the
damaging effect of solar UV rays, it is increasingly difficult for sunscreen
alone to protect effectively. So while covering up, slathering on the
sunscreen, and avoiding the sun during peak hours are still important to
prevent a burn, consider dietary changes too, to promote skin health. The
research is getting attention: for the first time, the Israeli Cancer
Association has included the nutritional information as part of their "Smart in
the Sun" advisories.
It's not necessary to move to Greece, Israel or Turkey to get the benefit of the
diet. Most of the appropriate foods are stocked in American grocery stores.
Olive oil, fresh fish, fruits and vegetables, red wine in moderation, whole
grains, beans and lots of water should be at the top of the shopping list, Dr.
Shapira advises. And there are some foods to avoid, she points out. Go light on
red meat, processed foods, and alcohol (red wine is preferable), and be wary of
foods that contain the photosensitizing compound psoralen, such as parsley,
celery, dill, cilantro and figs.
Skin Cancer May Be Linked To Virus
A virus discovered in 2009 in a rare form of skin cancer has also been found in
people with the second most common form of skin cancer among Americans,
according to researchers at the Ohio State University Comprehensive Cancer
Center - James Cancer Hospital and Solove Research Institute.
The researchers examined tissue samples from 58 people with squamous cell
carcinoma (SCC), a highly curable form of skin cancer that is expected to
affect more than 200,000 Americans this year. They identified the virus in more
than a third of the patients and in 15 percent of the tumors tested. In
addition, all of the virus found in tumor cells had a mutation that could
enable the viral DNA to integrate into the DNA of the host cell. "This is
indirect evidence that the virus might play a role in causing some cases of
squamous cell carcinoma," says principal investigator Amanda E. Toland,
assistant professor of molecular virology, immunology and medical genetics and
a researcher with the Ohio State University Comprehensive Cancer Center - James
Cancer Hospital and Solove Research Institute.
The findings are published in a recent issue of the Journal of Investigative
Dermatology. The virus was first discovered in patients with Merkel cell
carcinoma, a rare, aggressive skin cancer that occurs mainly in the elderly and
people with a suppressed immune system. The people in the new study all had a
healthy immune system. "Originally it was thought that this virus caused only
this rare skin cancer, but our findings indicate that it is a lot more
prevalent than we initially thought."
To learn if people with SCC harbored the virus, Toland, working closely with
first author and graduate research associate Amy Dworkin and Ohio State
pathologists O. Hans Iwenofu and Sara B. Peters, examined DNA samples from SCC
tumors, from normal-appearing skin adjacent to the tumor, when available; from
white blood cells, and from cells washed from the mouth. The investigators
detected the virus in 26 of 177 SCC samples, 11 of 63 adjacent-skin samples,
and one sample from a mouthwash. They found no viral DNA in any of the blood
samples from 57 patients. In all, 21 of 58 SCC patients, or 36 percent, tested
positive for the virus. By sequencing the viral DNA from 31 normal and tumor
samples, the researchers showed that the same mutation was present in all the
viruses tested from tumors, and in 60 percent of the viruses tested from
adjacent healthy-looking tissue. "That suggests that the virus may develop a
mutation that causes it to integrate into host-cell DNA, and, therefore, may
play a role in causing the cancer," Toland says.
Next, Toland wants to test normal skin in healthy individuals to learn how
common this virus is in people generally and to learn whether the virus
actually integrates with the host DNA. "If it proves to be a cancer-causing
virus, and if it proves to be common in the general population, it might be
something we should begin screening people for," she says.
Funding from the American Cancer Society supported this research. Ohio State
researchers Stephanie Y. Tseng and Dawn C. Allain were also involved in this
Articles from ScienceDaily SPF on Your Plate: Researcher Connects the
Mediterranean Diet With Skin Cancer Prevention (8/10) and Virus Linked To Some
Cases Of Common Skin Cancer (8/09)