Ep. 301: Sunscreen, Sun Exposure & Sunburns

In this episode, Stacy and Sarah are talking all about the pros and cons of the very sun in the sky!
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The Paleo View (TPV), Episode 301: Sunscreen, Sun Exposure & Sunburns
Intro (0:00)
News and Views (0:40)
This week's podcast breaks the record for most research done on a topic for a podcast!
We're hoping to give you well-rounded, consensus, and nuanced information.
There is a lot of science on this information, and it doesn't always agree.

Shoutout to our listeners for sending wonderful supportive feedback after we asked last week!

Sun & Skin (12:25)
The background: Stacy's family is very fair-skinned, and she is very aggressive with sunscreen use. She has looked into the safety of sunscreen- what kind of sun is good and not good, plus not adding harmful chemicals to our bodies.
What are risk factors for skin cancer?
This is the dominant motivator for wanting to protect our skin.
Sun exposure is a risk for skin cancer, but is different for different forms of skin cancer.
Melanoma: most dangerous, highest mortality rate.
More related to sporadic intense exposure with burns.
Interestingly, people tend to get this on parts of body not most-exposed to sun.
This probably indicated that contributing factors are more complex.


Basal and Squamous Cell Carcinoma are much milder and typically easier to treat.
The highest risk is total UV exposure, cumulative to date.
The more sun exposure, especially burning, the higher your chance.


There are other risk factors for skin cancers (and other cancers) as well:
Vitamin D deficiency.
Exposure to chemicals.
Having a weakened immune system.
Smoking.
Family history.
Fair complexion or being a red-headed.
Having moles increases risk of Melanoma.

Men are at higher risk of skin cancer than women.
Is it true that childhood sunburns increase your risk of skin cancer later on in life?
One study showed that overall there was no increase risk for melanoma.
There was a slight increased risk for melanoma in your 20s, but not overall in life.

There is a group of studies showing that sun exposure is a risk factor for skin cancer.
It is likely a collection of factors.
For example, sun exposure in the context of not getting enough antioxidants in the diet.
In the context of increased inflammation from chronic disease.
In the context of vitamin D deficiency.
In the context of more chemical exposure.



Sun Tan vs. Sun Burn
These are two different things, caused by two different mechanisms.
A sun tan is caused from melanocytes in the skin producing melanin (a dark pigment).
Having a lot of melanin in your skin protects from damage from the sun.
This is why people with darker complexions have lower risk of skin cancer.

Burning is really just cellular damage.
When you have a lot of cells dying from sun exposure, it triggers an inflammation response- which is what causes the heat/inflammation and and makes the skin so red.
How intense the sunlight is, and how long you were out in it versus how fair you are is the formula for a sunburn.



Sunscreen use related to skin cancer risk.
Prior to 1980 this was true, which is probably because there were a lot of chemicals used in sunscreen that have since been removed.
These chemicals were inert by themselves, but when exposed to the sun turned carcinogenic.

Currently no form of skin cancer is associated with sunscreen use.
There is a collection of studies that looked at prevention of skin cancer with sunscreen use.
These studies didn't show a strong effect.
This may be because people are using sunscreens to stay out in the sun longer.
It may have to do with the type of sunscreen they are using.



Benefits of non-burning sun exposure.
Could people be going so overboard with sunscreen use that they are missing out on some of the benefits of sun non-burning exposure?
Vitamin D deficiency: 75% of Westerners are vitamin D deficient.
Stress