July 14th, 2020
Melanoma is the most dangerous form of skin cancer, but it is by far not the most common. It can be found on any part of your body including places that never see the sun. This makes the sun a strange cause for this type of skin cancer as opposed to the other types which mainly occur on sun exposed places and increase in incidence with sun exposure volume and frequency. However, melanoma incidence, epidemiologically, increases with UV radiation exposure, yet also has other etiologies that are still being elucidated. (Arise et. al. 2018)
There is a continuing debate in the medical community as to whether melanoma is truly caused by excess sun exposure or not. I fall on the side of "judicious sun exposure is ok" and probably protective against all cancers. Do not burn, especially before 18 years of age, and you will likely have a healthy naturally vitamin D level and lower risk of skin cancer. Evolutionarily, it would make little sense to have sun exposure as a route to disease unless there is a mismatch of sun intensity and volume to host genetics. For example, a genetically lighter skinned individual that would have lived at a northern latitude, but instead chooses to live in Florida or visa versa with a genetically darker skinned individual living in Boston. This mismatch could be the risk precursor to increased skin cancers in general.
Melanoma is 15+ times more common now than it was 70 years ago. This is not a genetic mistake. Humans absolutely spent more time outside over the past 100 years than they do now. They rarely wore sunscreens and had less disease. Something is dramatically amiss now and is worsening. Caucasians suffer from melanoma at significantly higher rates by an order of magnitude from all other ethnic groups. (CDC) Thus, skin pigment seems to be a major determinant. This is association and not causation.
Many of our ancestors of all ethnicities lived in the intense sun based climates for hundreds of years but melanoma is a relatively recent incident worsening. What is the true reason? I am not quite sure, but I don't think that the sun is the primary driver as the sun is a constant where we and our lifestyle habits are the variables. Is the sun more intense? Nope!
Let's flip the debate and look at it through a different lens. I am going to try and simplify a complex topic. We know that vitamin D levels are profoundly lower and that many cancers similarly higher for obese sedentary indoor loving individuals. Could it be a combination of metabolic disease, a lack of physical activity, a lack of sun exposure, exposure to chemicals among other unnatural lifestyle induced variables converging and driving all of the issues at once? We know that vitamin D supplementation alone over a 5 year period in older adults had no effect on long term all cause cancer risk. (Manson et. al. 2019) Thus, if supplementation of vitamin D is of no significant benefit for cancer in general, is it not useful at all? Or, better yet, is it a piece of a total puzzle that when completed derives a vastly different picture of cancer.
We have data that anti-diabetic drugs like metformin do reduce cancer risk through mechanisms believed to be in opposition of the metabolic problems of hyperglycemia and mitochondrial damage. Diabetes is an unnatural response to a poor quality high refined carbohydrate and high poor quality fat diet. The system is constantly and poorly trying to handle the insane volume of free fatty acids from the fat and the excess sugar of the SAD diet. Eventually, the system cannot stuff more fat into the adipose and liver cells leading to increased sugar in the blood stream and all of the immune and metabolic nightmares that follow. Thus, it leads one to realize or hypothesize that reversing the metabolic effects of diabetes would be protective. Vitamin D deficiency is mostly related to the unnatural prolonged indoor activity limiting sun exposure and has profound effects on immune activity, especially mechanistically, as it relates to cancer. Movement would increase the translocation of GLUT4 receptors and other factors that fight metabolic disarray. Could these among other metabolic dysfunctional events be leading us down the primrose path toward cancers of all types? Remember that the sun is a constant as it relates to melanoma. Could it be the metabolic changes that allow the sun to be more dangerous now, especially for the lightest pigmented among us?
It would thus make more natural sense to me that these diseases in general are a function of choice that pits your host genetics against a mismatched lifestyle/societal choice. One thing is not to blame so much as a combination of dysfunctional choices combining to appear as we see disease. Not being able to completely prove the hypothesis, I fall back on the how to help your children remain with the least risk.
To prevent skin cancer:
1) Keep sun exposure to the safe level where you never burn your skin especially when you are under 20 years of age. This reality is completely related to your inherent genetic skin pigment.
2) Use high quality 30+ SPF sun block and effective clothing to prevent burns.
3) Maintain a healthy body weight through quality movement, nutrition, chemical avoidance and sleep.
Read this discussion: Link
See this site for more information.
To prevent cancer progression, what does one look for? Early identification is the key to any cancer survival.
1) Asymmetry of the lesion - not round
2) Irregular borders - jagged, finger like
3) Irregular non uniform color
4) Usually greater than 6 mm in size
5) Any change - in size, shape, color, elevation, or another trait, or any new symptom such as bleeding, itching or crusting - points to danger.
The Mayo Clinic has an excellent slide show to help differentiate these types of changes. Link
Be aware and be smart,
Arisi Frontiers in Medicine
Manson NEJM Trial
Pereira-Santos Obesity Reviews
Yu Frontiers i Endocrinology
Saraei Cancer Management and Research
Cowey American J of Pathology
Geller J of Clin Oncology