Summer is in full swing. That means hot days at the beach, cookouts with friends, much needed vacations, and a substantially increased risk of skin cancer.
If that last one caught you off guard, this article’s for you. Nutrition has been found to play a critical role in preventing certain diseases, and skin cancer is no exception. While there’s no excuse for skipping your daily fruits and veggies, research shows that at least with skin cancer, that might not be enough. According to a 2015 meta-analysis of 9 studies, a diet high in fruits and vegetables was not linked to reduced melanoma rates. Fortunately, modern research has shown that supplementing a balanced diet with specific vitamins holds some promise.
The Top Performers
Supplementing your diet with vitamin A1 (retinol) might reduce your risk of skin cancer, especially if you’re already careful about using proper sunscreen. Consumption of retinol has been shown in some studies to reduce melanoma rates, but be aware that beta-carotene (the plant form of vitamin A) has not. Your body naturally converts beta-carotene into retinol, but the two act a little different physiologically. In the study, researchers linked high-dosage retinol consumption of >1800 mcg/day to a reduced risk of skin cancer in women.
Don’t overdo it. As opposed to beta-carotene, retinol can be toxic or even fatal if over-consumed, and there have been studies linking elevated dosages of retinol to bone weakness. Pregnant women especially should not take high-dose retinol as it can cause birth defects. The NIH-recommended daily dosage for adults is 700-900 mcg daily (3,000 mcg/day maximum). More studies are in the works for retinol, and until then you should be fine just taking the recommended daily dose.
Vitamin B is actually a group of eight different vitamins, with distinct functions in your body, and only one of the B vitamins has been linked to lower skin cancer rates. In a study of 386 high-risk patients with a previous history of nonmelanoma skin cancer, high doses of vitamin B3 (nicotinamide, a form of niacin) was shown to reduce the chances of new skin cancer by 20%.
Again, stick to the recommended daily dosage of 14-18 mg (maximum 35 mg). Vitamin B3 can cause headache, dizziness, and an increased risk of liver damage at high dosages, so don’t increase your B vitamin intake without consulting your doctor first.
Even if it doesn’t prevent skin cancer, some studies indicate that vitamin D supplements might reduce the stage or thickness of a skin cancer growth when it first develops, and improve survival rates of patients receiving therapy for melanoma. It’s important to distinguish here that these studies are not saying that vitamin D can be used to treat cancer - they only say that vitamin D might make patients with skin cancer less likely to develop a particularly severe form, and might have been related to better treatment outcomes in patients who were also receiving proper medical treatment. The recommended daily dosage for vitamin D is 600 IU.
Grape Seed Extract
Research on grape seed extract and skin cancer is limited, but animal studies and preliminary human studies have yielded some positive results. Grape seed extract given to mice was associated with a decrease in UV-induced skin tumor development, for example. Additionally, in a study of 830 subjects, researchers found a 69% reduction in odds of squamous cell carcinoma in the 17 subjects who reported taking supplemental grape seed extract. Before you get too excited, remember that wine is not a sufficient source of grape seed. The average grape seed extract dosage wasn’t reported in the human survey study, and there are no established daily recommended dosages. Typically, doses range from 50 to 300 mg per day.
Where Science Doesn't Support the Hype
For the following supplements, you may have heard promising stories, but the truth is we just haven’t studied these compounds well enough yet. Some have been the subjects of multiple studies with conflicting conclusions, and others might just not be effective in reducing your risk of skin cancer at all.
Vitamin C Might be Bad or Good
Despite vitamin C’s claimed benefits, we still don’t know enough about it’s impact on our bodies, at least in relation to skin cancer. One small Italian study suggested that vitamin C had a protective effect against skin cancer, but other researchers are saying that the evidence is still inconclusive. A group of American researchers have even said that too much vitamin C could be bad. In a large study of 121,700 female nurses, researchers were surprised to find a link between high vitamin C consumption from foods and elevated skin cancer rates. But don’t panic. The quantity of vitamin C consumed in this study was far beyond the daily recommended dosage of 75-90 mg. Interestingly, women who got little vitamin C from foods, but took it as a supplement, did not experience an increased cancer risk.
Little Evidence for Vitamin E, Selenium, or Multivitamins
There’s no current indication that vitamin E or selenium have any impact on your chances of developing skin cancer and although multivitamins have been shown to reduce the likelihood of developing cancer overall, they haven’t shown much for skin cancer specifically.
Antioxidants Do Well in the Lab, But Not the Real World
Specific antioxidants have demonstrated the ability to prevent and kill cancer cells when examined under a microscope, but antioxidants in general haven’t shown this same effect when studied as a broad category in human research. This might be due to poor study design. Patients were often surveyed about their reported use of “antioxidants”, but that broad term could have encompassed everything from chocolate to the vitamins listed above. It could also be that the effect of too much sun exposure is still more important than antioxidant consumption in developing skin cancer.
Ready. Set. Summer.
We’ve given you a summary of relevant research on skin cancer, but before you race out to buy a list of summer supplements, discuss them with your doctor and make sure you check Labdoor’s data to find out exactly how much of each vitamin you’ll be getting and if they’re safe. All in all, if you eat a balanced diet, get your daily dose of vitamins and minerals, and follow proper sun safety behavior — always apply sunscreen 30 minutes in advance and limit your time spent under direct sunlight — you’ll be in better shape to enjoy your next day at the beach.
- Co-author: Benita Lee
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