I wanted to find a way to create a deeper connection with my followers and provide more insights into the content I share on other platforms. I'm excited to give you all a closer, more personal look into my world—sharing insights from my life, my research, and work.

Yesterday marked the official beginning of summer, so I wanted to share a few thoughts on the relationship between the sun and cancer!

I’ve spoken about this topic frequently on social media because many people have been taught to fear the sun. While excessive sun exposure and sunburns can absolutely be harmful, the conversation is often far more nuanced than "sun equals skin cancer."

The sun plays a critical role in human health. It helps regulate our circadian rhythm, supports hormone production, influences immune function, and is our most natural source of vitamin D—a nutrient that has been extensively studied for its role in immune health and cancer prevention.

Unfortunately, many people spend their days indoors, avoid sunlight altogether, and rely on sunscreen from morning until night. As a result, vitamin D deficiency has become incredibly common.

The goal is not to avoid the sun. The goal is to develop a healthy relationship with it. Getting regular, sensible sun exposure while avoiding burns is very different from baking in the sun for hours without protection.

As with so many things in medicine, balance matters. The answer is rarely found in extremes. The sun is not the enemy—it is one of the most powerful forces in nature, and when approached wisely, it can be an important part of a healthy lifestyle. 🌞🤍

This topic is complicated because each person has their own biological makeup and risk factors for skin cancer. While it’s extremely important to avoid burns, the internal cancers that are associated with inadequate low sunlight exposure and vitamin D deficiency are more aggressive and have worse outcomes. For example, colon cancer has a 5-year survivability rate of 65%, while basal cell carcinomas have a 5-year survivability of 100%.

In the United States, from 2009 to 2019, the number of new melanoma cases is estimated to have increased by over 40%, and over the last three decades, the percentage of individuals who develop melanoma has more than doubled (PMID: 38136411).

Although public health messages to avoid the sun, wear sunscreen, and limit UV exposure are intended to reduce skin cancer risk, melanoma rates have continued to rise. This suggests that additional factors may be influencing risk.

Skin cancer is a biologically complex disease influenced by ultraviolet radiation, hormones, immune function, vitamin D status, metabolic health, and environmental context. Reducing it to a single cause may overlook the broader terrain in which develops.

The sun is not simply a source of UV radiation—it is one of the most powerful environmental signals our bodies receive that helps regulate countless processes throughout the body. Some thoughts: ⬇️

10 Reasons I Don’t Avoid Sunlight as a Doctor Who Treats Cancer: 🌞

1. It reduces the risk of internal cancers: Many studies have found that greater sunlight exposure is associated with lower rates of cancers such as colorectal, breast, prostate, pancreatic, and ovarian cancer. One of the primary reasons is vitamin D. When ultraviolet B (UVB) light from the sun reaches the skin, it triggers the production of vitamin D, which helps regulate cell growth, cellular differentiation, apoptosis (programmed cell death), and immune function. These are all critical mechanisms involved in preventing abnormal cells from developing into cancer.

2. It balances cortisol levels: Cortisol is often called the body's "stress hormone," but it is also one of our most important circadian hormones. Humans evolved to rise with the sun, and our bodies are designed for cortisol to naturally peak in the morning shortly after sunrise. This morning cortisol surge helps us wake up, feel alert, regulate blood sugar, support metabolism, and prepare for the demands of the day. Research shows that exposure to bright sunlight can bring cortisol levels back into balance, especially when elevated.

3. It sets our circadian rhythm and supports sleep: Sunlight entering the eyes shortly after waking sends a signal to the brain's master clock, helping synchronize this daily rhythm. As the day progresses and the sun sets, cortisol naturally declines while melatonin begins to rise, preparing the body for rest and recovery.

4. It supports mitochondrial function: Mitochondria are responsible for producing ATP, the energy currency of the cell. Sunlight contains red and near-infrared wavelengths that can penetrate tissues and interact with mitochondria. Research suggests these wavelengths may improve mitochondrial efficiency, increase ATP production, reduce oxidative stress, and support cellular repair. This is one of the same mechanisms utilized in red light therapy devices.

5. Most cancer patients are vitamin D deficient: Vitamin D helps regulate some of the most important anti-cancer mechanisms in the body, including immune surveillance, cellular differentiation, DNA repair, and programmed cell death. Researchers have found vitamin D receptors on many cancer cells, and low vitamin D levels are consistently associated with increased cancer risk and poorer outcomes. When UVB light touches the skin, the body begins producing vitamin D naturally, so regular sunlight exposure may help support many of the biological pathways involved in cancer prevention.

6. It improves circulation: Sunlight gently warms the body, causing blood vessels to expand and increasing blood flow to tissues throughout the body. Improved circulation helps deliver oxygen, nutrients, hormones, and immune cells where they are needed most while also supporting the removal of cellular waste products. Much like a sauna, the warmth of sunlight supports healthy circulation and helps the body function more efficiently.

7. It contains infrared light which supports tissue regeneration: Nearly half of the sun's energy exists in the infrared spectrum. Unlike UV light, infrared wavelengths penetrate deep into tissues where they may support wound healing, collagen production, cellular repair, and recovery. This is one reason sunlight has historically been used therapeutically to support healing and rehabilitation. In fact, in the late 19th and early 20th centuries, heliotherapy—the therapeutic use of sunlight—was commonly used in hospitals and sanatoriums to treat conditions such as tuberculosis, chronic wounds, surgical recovery, and skin diseases.

   

   Heliotherapy. Polio and arthritis patients in beds on the roof of a hospital. NATIONAL LIBRARY OF MEDICINE / SCIENCE PHOTO LIBRARY

8. It is anti-inflammatory. Researchers have found that sunlight exposure can influence immune activity throughout the body, helping shift the immune system away from a chronically activated, inflammatory state. Sunlight exposure can suppress excessive inflammatory responses. This may help explain why conditions such as multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, and other autoimmune disorders tend to be more common in populations with lower sun exposure.

9. It improves mood and mental health. Sunlight is one of the few environmental factors that has been repeatedly linked to mental health outcomes across populations. Studies have found that people with greater sunlight exposure tend to have lower rates of depression, seasonal affective disorder (SAD), and psychological distress. In fact, the therapeutic use of light is so effective that bright light therapy has become a recognized treatment for certain mood disorders.

10. It supports healthy cellular differentiation: Vitamin D from UVB light binds to receptors in cells throughout the body and influences the expression of genes involved in cellular maturation. This helps guide immature cells to develop into specialized cells with specific functions rather than remaining in a rapidly dividing, undifferentiated state. Researchers have found that vitamin D can promote differentiation in a variety of tissues, including breast, colon, prostate, and immune cells, which is one reason it has been extensively studied in cancer prevention and cancer biology.

Sunlight: Nature's Original Light Therapy 🌞

Today, many people are investing in red light therapy devices to access the benefits of infrared and near-infrared light. While these tools can be incredibly beneficial, it's helpful to remember that the sun is the original light therapy device! The sun provides a full spectrum of biologically active wavelengths that work together in ways we are still learning to understand.

Much of the light from the sun consists of infrared or near-infrared wavelengths. These wavelengths can penetrate deep into our skin and cells, where they stimulate various cellular processes. However, both ultraviolet and infrared exposure have important physiologic effects.

Some benefits:

🏮Infrared/near-infrared light -
- Improves mitochondrial health & energy production
- Promotes cell regeneration
- Anti-inflammatory
- Improves mood
- Improves circulation
- Stimulates wound healing
- Boosts immune function

🌞UV light -
- Stimulates vitamin D production
- Increases melanin
- Kills viruses and bacteria
- Improves skin conditions (Psoriasis)
- Improves circulation
- Improves mood

Protecting the Skin and Healthy Exposure

This conversation is nuanced because while sunlight is a powerful health tools, we should avoid sunburns whenever possible. Sunburns are associated with an increased risk of skin cancer, so the goal isn't excessive sun exposure—it's developing a healthy, balanced relationship with the sun.

The amount of sun that's right for you depends on many factors, including your skin tone, genetics, geographic location, time of year, etc. Even your diet and hormone levels can influence your susceptibility to burning. Learning how your body responds to sunlight is important.

When spending extended periods of time outdoors, sun protection is important. However, many conventional sunscreens contain chemicals that can be absorbed through the skin and detected in the bloodstream. Some of these ingredients have raised concerns due to their potential endocrine-disrupting, estrogenic effects and carcinogenicity. I recently shared a post on this here. Because of this, I use non-toxic sunscreens. Primally Pure’s tallow based sunscreen is my favorite! (code: CONNEALYMD)

A few additional tips for safe and beneficial sun exposure:

• Get morning and evening sunlight whenever possible to maximize exposure to beneficial infrared and near-infrared wavelengths.

• Avoid burns by wearing hats, lightweight cotton clothing, seeking shade when needed, and using a non-toxic sunscreen during prolonged sun exposure.

• Minimize seed oils in the diet. These highly unsaturated fats can become incorporated into cell membranes, where they may be more susceptible to oxidation from heat and light, potentially increasing sensitivity to sun damage.

• Build sun tolerance gradually. Consistent exposure during the spring and early summer months allows the skin to adapt naturally over time.

• Avoid the "vacation effect" of getting very little sun for months and then spending an entire day baking in the sun. Regular, moderate sun exposure is generally far better tolerated than occasional extreme exposure.

• Support your skin from the inside out. A nutrient-dense diet rich in antioxidants, vitamin C and E is highly protective against the oxidative stress caused by UV exposure.

• Get sunlight year-round. Consistent exposure throughout the year is often better tolerated than avoiding the sun for months and then suddenly spending an entire day in it.

• Pay attention to medications. Certain medications like antibiotics can increase photosensitivity and make you more prone to burning.

• Avoid harsh personal care products before sun exposure. Some ingredients can make the skin more sensitive to sunlight.

Excessive sun avoidance is carcinogenic. In our efforts to avoid the sun (more so than any generation before us), rates of cancer continue to rise. We are designed to receive the sun’s inputs. Achieving a balance between safe sun exposure and protection from harmful UV rays is key to maintaining health and connection to nature. It’s important to make peace with our environment and find a healthy relationship with the sun.

Elham’s Liquid Gold

Just as important as protecting the skin is supporting its ability to repair and regenerate. Healthy skin depends on a strong skin barrier, adequate hydration, and the nutrients needed to recover from daily environmental stressors, including sun exposure.

I use castor oil daily! My favorite is Elham's Liquid Gold.💛

✨ Benefits of Castor Oil

• Rich in ricinoleic acid

• Supports a healthy skin barrier and helps reduce moisture loss

• Provides long-lasting hydration without many synthetic ingredients

• Rich in antioxidants

• Helps soothe dry, irritated skin

• Supports the skin's natural repair and regeneration processes

• Can be used on the face, body, scalp, eyelashes, and eyebrows

• Traditionally used to support lymphatic flow and circulation when applied through castor oil packs

It's organic, cold-pressed, hexane-free, and free from many of the unnecessary additives found in conventional skincare products.

Use code LEIGHERINCONNEA for 10% off!

Join us next week at the Beljanski Conference!

I’m so excited to invite you all to San Diego for the 2026 Beljanski Integrative Cancer Conference—an immersive 4-day event bringing together some of the world’s leading voices in integrative, metabolic, and functional oncology.

🗓 June 26th–29th, 2026
📍 San Diego, California

At the conference, I will be speaking alongside top doctors, researchers, scientists, and cancer experts as they discuss the latest breakthroughs in natural cancer prevention, metabolic therapies, immune support, mitochondrial health, cancer stem cell research, integrative treatment strategies, and the future of oncology.

Tickets are now on sale now- use code BICC26CONNEALY for 15% off!

The Center For New Medicine is expanding.

The Center for New Medicine team is growing! We’re looking for exceptional physicians to join us and building a team of the best—clinicians who are passionate about solving complex cancer cases and thinking beyond conventional approaches.

If you’re interested in working alongside me and being part of a more integrative, patient-centered model, please send an email with a brief introduction and your area of focus to [email protected].

If you are looking for personal guidance on prevention and health optimization you can contact the center at 949-680-1880. Our team takes the most comprehensive approach and looks at all the underlying metabolic, nutritional, emotional, and environmental factors that influence health. For a full list of services, please see below!

The Cancer Revolution is now available ❤️

This book is my guide to cancer prevention and treatment. In this fully updated second edition, I walk through how I approach cancer from an integrative, metabolic perspective.

I go deeper into:

• The lab markers I monitor

• Cancer-specific testing and early detection tools

• How metabolic dysfunction precedes tumor formation

• Hormone balance, inflammation, and mitochondrial health

• Updated nutrition guidance and structured food plans

• Practical lifestyle interventions that support cellular repair

• Emerging tools including immunotherapy and voltage/frequency medicine

This edition is designed for anyone who wants to understand cancer beyond genetics—and learn what can be done proactively, both for prevention and during treatment.

There’s so much we can do to support healing and live a full, cancer-free life. 💪

• Amazon 

• Hachette Book Group

• Barnes & Nobel 

• Books a Million

• Bookshop 

Talk soon ❤️,

Dr. C