Adequate Vitamin A Reduces Risk Of Skin Cancer

People who eat a diet rich in vitamin A have a 17% reduction in the risk of squamous cell skin cancer, researchers at Brown University say based on data from two of the largest long-term observational studies. The results are published in JAMA Dermatology.

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Squamous cell skin cancer is the second most common type of skin cancer in fair-skinned people. Vitamin A is known to be essential for healthy growth and maturation of skin cells, but previous research on its effectiveness in reducing the risk of skin cancer has been mixed.

Sources of vitamin A include sweet potatoes, melon, carrots, asparagus beans, bell peppers, broccoli, spinach, dairy products, fish, and meat, especially liver, according to the US National Institutes of Health. It is a fat-soluble vitamin and therefore can accumulate in fat cells. Adults should not consume more than 10,000 international units (IU) of preformed vitamin A per day.

Reception in large quantities (for example, in the form of dietary supplements or animal products) is unsafe - it can cause nausea, structural and functional changes in the liver, increases the risk of osteoporosis, hip fractures, birth defects in future offspring. However, the side effects of a high intake of vitamin A from plant sources are minimal.

“Our study provides further justification for consuming large quantities of fruits and vegetables as part of a healthy diet. Skin cancers, including squamous cell carcinoma, are difficult to prevent, but this study shows that following a healthy diet rich in vitamin A may be a way to reduce risk, in addition to applying sunscreen and reducing sun exposure,”said study lead author Yunyong Cho. Eunyoung Cho).

In the study of the health of nurses (1984-2012) and medical workers (1986-2012), a team of scientists analyzed the diets of 75,170 women and 48,400 men. Participants were fair-skinned, had no cancer at the time of study entry, and completed nutritional self-reports several times. Among them, 3978 cases of squamous cell carcinoma were registered and confirmed during the entire observation period.

In addition, factors such as hair color, number of serious sunburns received during life, family history of skin cancer were taken into account.

The researchers categorized five groups for vitamin A intake and found that people with the highest average daily total intake of vitamin A were 17% less likely to develop skin cancer than those with the lowest total vitamin A in their diet. The highest level is equivalent to two large carrots per day (21,000 IU) and the lowest is equivalent to one small carrot (7,000 IU).

The results showed that the vitamin A in the participants' diets came primarily from fruits and vegetables, rather than animal products or vitamin supplements. Vitamin A has been shown to be protective for people with multiple moles and severe sunburns in childhood or adolescence.

Additionally, the researchers found that eating a lot of other plant pigments, in particular lycopene (found in tomatoes and watermelons), was also associated with a reduced risk of skin cancer.

As noted by the researchers, taking vitamin A supplements does not reduce the risk of squamous cell skin cancer.

Since the analysis was based on observational data, a causal relationship cannot be established. Perhaps other factors also played a role. In particular, people who consumed more vitamin A drank less alcohol and exercised more. But nonetheless, vitamin A contributes to the maintenance of healthy skin cells, which may be why it is associated with a lower risk of squamous cell carcinoma.