You and the Sun

As more people become mindful of what they put on their skin and the environmental impact of chemical sunscreens, interest in natural alternatives to sun protection is growing. At the same time, there’s also curiosity about how to optimize sun exposure for vitamin D production.

The Role of Sunscreen—and the Concerns

Certain chemical sunscreens (such as those containing oxybenzone or octinoxate) have been linked to skin irritation, hormonal disruption, and marine ecosystem damage. For those seeking a more natural approach, safer and effective alternatives are available.

1. Zinc Oxide (Non-Nano)

A physical blocker found in many natural sunscreens.
Reflects UVA and UVB rays without being absorbed into the bloodstream.
Look for formulations free of parabens, synthetic fragrances, and nano-particles.

2. Coconut Oil & Shea Butter

Very low natural SPF (~5–7), not sufficient alone for prolonged sun exposure.
Better used as moisturizers after sun exposure.

3. Protective Clothing and Shade

Wide-brim hats, long sleeves, and UV-blocking fabrics can be very effective.
Seeking shade during peak UV hours (10 a.m.–2 p.m.) is a smart habit.

Note: These natural products should not be relied on for high-intensity sun exposure (e.g., midday beach days), but can be supportive for low-level sun exposure.

Vitamin D

☀️ How Your Body Makes Vitamin D

When UVB rays hit your skin, they convert a cholesterol compound (7-dehydrocholesterol) into pre-vitamin D3, which is then converted to vitamin D3 over the next 48 hours.
This process occurs in the skin, and the compound needs to remain on the surface long enough to be absorbed into the bloodstream.
To optimize vitamin D production, aim for moderate sun exposure (10–30 minutes depending on skin tone and location), and wait at least 30–60 minutes before showering to maximize absorption.
When in doubt, consult a dermatologist—especially if you have fair skin, a history of skin cancer, or live in a high UV region.

Your Skin, Naturally Protected

Taking care of your skin doesn’t mean avoiding the sun entirely—it means being smart about your exposure and protection. By blending modern science with natural practices, you can support your health while minimizing risks.

Key Sunscreen Chemicals

1. Oxybenzone (Benzophenone-3)

What it does: Absorbs UVB and some UVA rays.
Concerns:
- Hormone disruption: Acts like estrogen in the body; associated with reduced sperm count, altered thyroid function, and early puberty in some animal studies.
- Skin absorption: Studies by the FDA show that oxybenzone can be detected in the blood at levels higher than what is considered safe, even after a single use.
- Cancer link: While no human study has directly proven it causes cancer, its estrogen-like activity and oxidative stress may potentially raise long-term cancer risks.

2. Octinoxate (Octyl Methoxycinnamate)

What it does: Absorbs UVB rays, used for preventing sunburn.
Concerns:
- Found to disrupt the endocrine system in animal studies.
- Linked to thyroid hormone changes and altered reproductive function.
- Can generate free radicals under UV exposure, potentially damaging DNA.

3. Homosalate

What it does: Absorbs UVB rays and helps sunscreen penetrate skin.
Concerns:
- May accumulate in the body faster than it breaks down, increasing toxicity risk over time.
- Shown to disrupt estrogen, androgen, and progesterone in lab studies.
- Some studies suggest it enhances the absorption of other harmful chemicals.

4. Avobenzone

What it does: Absorbs UVA rays (the kind that penetrate deep and cause aging).
Concerns:
- Breaks down quickly in sunlight unless stabilized with other chemicals (which can be toxic).
- When mixed with chlorine (e.g., in pools), it can degrade into potentially cancer-causing compounds like aromatic amines.

How Could These Chemicals Contribute to Cancer?

The link between these sunscreen ingredients and cancer is based on potential mechanisms like:

1. Hormonal Disruption

Hormone-disrupting chemicals can interfere with estrogen, testosterone, and thyroid hormones, all of which play key roles in regulating cell growth and immune function.
Chronic hormone disruption is a known risk factor for hormone-sensitive cancers like breast, prostate, and thyroid cancer.

2. Oxidative Stress

Some sunscreen chemicals can generate free radicals when exposed to sunlight, which can damage DNA and cell structures—a hallmark of cancer development.

3. Systemic Absorption

The FDA has confirmed that some sunscreen chemicals are absorbed into the bloodstream, sometimes in concentrations exceeding safety thresholds, without clear understanding of long-term effects.
Chronic systemic exposure raises concern about cumulative toxic effects.

Bottom Line

Some ingredients in chemical sunscreens raise significant red flags, especially with frequent, long-term use.
Safer choices include mineral sunscreens, protective clothing, and limiting sun exposure during peak hours.
Always read labels, opt for broad-spectrum protection with clean ingredients, and consider consulting a dermatologist for personalized guidance.

Do Sunglasses Trick Your Body and Contribute to Sunburn?

This idea comes from the concept that your eyes help regulate your body’s response to sunlight—particularly through melanocyte-stimulating hormone (MSH) and other light-sensitive pathways in the brain.

The Theory:

When sunlight enters your eyes, it triggers a cascade in the hypothalamus that alerts your body to produce melanin, your natural sun protection pigment.
Wearing sunglasses blocks visible light, particularly blue light, which may:
- Reduce the signal to the brain that the body is in bright sunlight.
- Delay or suppress the skin’s natural preparation for UV exposure (e.g., tanning or melanin production).
- Make your skin more prone to burning instead of tanning, because the body is “tricked” into thinking it’s in the shade.

What Does the Research Say?

The idea is supported by what we know about photoreception and light-induced hormone regulation:
- Sunlight stimulates MSH, which promotes melanin production.
- Melatonin levels, which are tied to circadian rhythm, are influenced by sunlight exposure to the eyes.
Blocking light may disrupt the body’s ability to synchronize with its environment, including UV readiness.

If you’re outside for long periods, gradual sun exposure and natural light in the early day (without sunglasses for a short time) may help regulate melanin without risking eye health.

Does Consuming Seed Oils Make You More Likely to Burn?

Most common seed oils—such as canola, soybean, corn, sunflower, cottonseed, and grapeseed oil—are high in omega-6 polyunsaturated fatty acids (PUFAs), particularly linoleic acid. These fats are:

Highly unstable and prone to oxidation, especially when exposed to heat, light, and oxygen.
Stored in your skin and cell membranes if consumed regularly.

How Seed Oils May Promote Sunburn:

When UV light hits your skin, it creates oxidative stress.
If your skin contains a high concentration of omega-6 fats, these fats can oxidize more readily, creating inflammatory byproducts (like lipid peroxides).
This makes your skin more prone to inflammation, damage, and sunburn.

Supporting Research:

Studies show that a high omega-6 to omega-3 ratio is linked to increased inflammation and skin damage.
A 2001 study found that diets high in omega-3s (from fish oil) made skin less sensitive to UV radiation.
Excessive linoleic acid in the diet has been shown to impair skin barrier function and promote inflammatory responses.

What to Do Instead:

Reduce seed oils in cooking and processed foods.
Focus on stable, natural fats: coconut oil, olive oil, butter, ghee, tallow.
Increase omega-3 fatty acids: wild-caught fish, flaxseed, algae oil.
Consume antioxidant-rich foods (vitamin C, E, polyphenols) to buffer UV stress.
Use coconut oil, olive oil, or avocado oil

Summary

Factor	Effect on Sunburn Risk
Wearing sunglasses	May block UV-signaling through the eyes, reducing melanin response and natural skin protection
High seed oil intake	Increases oxidative stress in the skin, making it more prone to UV damage and inflammation
Best practices	Get morning sunlight without sunglasses; reduce seed oils and increase antioxidant/omega-3 intake