Dr. Johnston looks at a 2000 study comparing 571 melanoma patients with 913 healthy controls, which reported higher odds of melanoma among regular sunscreen users, and a 2023 meta-analysis of vitamin D3 and cancer mortality. He notes the sunscreens averaged only SPF 6 and that users may have stayed in the sun longer. Part 1 of 2.
I read a study recently which frankly stunned me. I learned in medical school that melanoma, our deadliest skin cancer, is directly related to sun exposure. Researchers estimate that about 92% of melanoma cases are from sun exposure.
However, in 2000, a study was published looking at 571 melanoma patients and 913 healthy controls. And what they found was quite unexpected. Regular sunscreen users had an 80% increased odds of developing melanoma. Among those who said sunscreen allowed them to sunbathe longer, those who always use sunscreen had a 770% increased odds of developing melanoma compared to those who never use sunscreen.
As a blonde kid of Scottish descent, I was always getting sunburned. Whether I was fishing, mowing lawns, catching snakes, swimming at St. Augustine Beach, I always had my shirt off. We were simply too poor for sunscreen. But with this study, I'm beginning to wonder, maybe I should be thankful for that.
The average strength of the sunscreen in the study was only 6 SPF. Perhaps if they would have used a stronger sunscreen, it would have been more protective. Maybe if sunscreen users would have sought out the shade a little bit more instead of using that sunscreen as an excuse to get so much sun, maybe the risk wouldn't have been so high.
But there's more to this story. One of the major benefits of sun exposure is vitamin D3 generation in the skin. And vitamin D3 may be the most misunderstood supplement in cancer research. In 2023, researchers did a meta-analysis involving 10 randomized trials with 75,267 people taking between 40 and 4,000 international units of vitamin D3 daily. Cancer mortality was 12% lower than those taking placebo. To be precise, there were about 81 fewer cancer deaths in this study if the people took vitamin D3 compared to placebo. One can only wonder what the benefit would have been if they were taking 8,000 international units of vitamin D3 daily.
And here's where it gets controversial. I'll save that for part two. But it definitely looks like in moderation, unprotected sun exposure is far more beneficial than we were told it was. Here's the research. You decide.
Educational research summary, not medical advice. Talk with your oncologist and pharmacist before starting, stopping or changing any treatment or supplement.