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Full Version: Higher vitamin A intake linked to lower skin cancer risk
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https://www.brown.edu/news/2019-07-31/skincancer

EXCERPT: People whose diets included high levels of vitamin A had a 17 percent reduction in risk for getting the second-most-common type of skin cancer, as compared to those who ate modest amounts of foods and supplements rich in vitamin A. That’s according to researchers from Brown University, who unearthed that finding after analyzing data from two long-term observational studies. [...] The findings were published on Wednesday, July 31, in the Journal of the American Medical Association Dermatology....

Cutaneous squamous cell carcinoma is the second-most-common type of skin cancer among people with fair skin. Vitamin A is known to be essential for the healthy growth and maturation of skin cells, but prior studies on its effectiveness in reducing skin cancer risk have been mixed, said Eunyoung Cho, an associate professor of dermatology and epidemiology at Brown. “Our study provides another reason to eat lots of fruits and vegetables as part of a healthy diet,” said Cho, who is also an associate epidemiologist at Brigham and Women's Hospital. “Skin cancer, including squamous cell carcinoma, is hard to prevent, but this study suggests that eating a healthy diet rich in vitamin A may be a way to reduce your risk, in addition to wearing sunscreen and reducing sun exposure.”

[...] The team also found that the majority of vitamin A came from the participants’ diets, particularly from fruits and vegetables, rather than from animal-based foods or vitamin supplements. Plant-based sources of vitamin A include not only sweet potatoes and carrots, but leafy green vegetables and fruits like apricots and cantaloupe. Milk, some types of fish and liver are rich sources of animal-based vitamin A. ... The researchers also found that eating high levels of other plant-based pigments similar to vitamin A — such as lycopene, commonly found in tomatoes and watermelon — was associated with decreased risk of skin cancer...

[...] Cho cautioned that too much vitamin A, particularly from supplements and animal sources, can lead to nausea, liver toxicity, increased risk of osteoporosis and hip fracture, and even birth defects. Side effects from high levels of plant-based vitamin A are minimal, she added.

Because the analysis was based on studies surveying a large number of people about the foods they ate and observing whether or not they got skin cancer, rather than a randomized clinical trial, it cannot establish cause and effect. It’s possible that another factor may have led to the differences — such as the fact that people who consumed more vitamin A also tended to drink less alcohol. (MORE - details)