New Study Finds Sunlight Boosts Nitric Oxide Production

Skin Sunlight Exposure

Story at-a-glance

  • Sunlight causes your skin to produce nitric oxide, a critical compound for maintaining blood pressure that reduces your risk for heart attack and stroke
  • Benefits of sunlight exposure vastly outweigh risks of exposure. Evidence shows your risk of dying from skin cancer is 80 times lower on average than your risk of dying from a heart attack or stroke
  • Nitric oxide enhances blood flow, promotes blood vessel elasticity, lowers blood pressure, and functions as a signaling molecule in your brain and immune system
  • Elevated uric acid drives up blood pressure by inhibiting nitric oxide; overconsumption of fructose is the most significant factor underlying elevated uric acid levels in the US and other Western nations
  • The “melanoma epidemic” is grossly overstated; research shows 90 percent of melanoma surgeries are for benign lesions; the latest science suggests appropriate UV exposure is protective against melanoma


This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

By Dr. Mercola

By now, you are probably aware I am a strong proponent of sun exposure and its many health benefits. Most of those benefits come from the boost in vitamin D, but a new UK study suggests sunlight’s benefits extend far beyond vitamin D.

In fact, exposure to the sun may be one of the most important steps you can take in preventing heart disease and stroke. Scientists at the University of Edinburgh discovered that when sunlight touches your skin, nitric oxide is released into your bloodstream,1 and nitric oxide is a powerful blood pressure lowering compound.

Researchers have concluded sun exposure may even prolong your life by significantly cutting your heart attack/stroke risk. The abstract for the study was published online in the Journal of Investigative Dermatology on April 15, 2013.2

The Edinburgh researchers mentioned an absolutely stunning statistic. For every one skin cancer death in northern Europe, between 60 and 100 people die from stroke or heart disease, related to hypertension.

Knowing that your risk of dying from heart disease or stroke is 80 times greater on average than from skin cancer really puts it in perspective.3 While higher vitamin D levels also correlate with lower rates of cardiovascular disease, oral vitamin D supplements do not appear to benefit blood pressure, and this latest study may be telling us why.

Researcher Richard Weller stated:

"We suspect that the benefits to heart health of sunlight will outweigh the risk of skin cancer. The work we have done provides a mechanism that might account for this, and also explains why dietary vitamin D supplements alone will not be able to compensate for lack of sunlight."

You Are My Sunshine

Research is illuminating a forever-growing list of sunlight’s health benefits. This isn’t really surprising when you consider the fact that we evolved hunting and foraging under the sun.

This team of researchers found that your body's production of nitric oxide is separate from its production of vitamin D, so it follows that there are two completely separate sets of benefits. Until now, increased vitamin D had been thought to be the sole explanation for the sun's health benefits, but it appears from these latest findings that vitamin D is only one part of the story.4

Besides the benefits derived from increased vitamin D, the sun also provides relief from a wide variety of health problems from mechanisms separate from vitamin D. For a comprehensive overview, refer to our previous article on the sun’s benefits, but here are just a few:

  • Improved mood and energy levels through the release of endorphins
  • Better melatonin regulation and synchronization of your biorhythms
  • Suppression of the symptoms of fibromyalgia and multiple sclerosis
  • Treating skin diseases (including psoriasis, vitiligo, atopic dermatitis, and scleroderma) and antibiotic-resistant infections, such as MRSA
  • Treating tuberculosis, neonatal jaundice, and possibly T cell lymphoma

Why Care About Nitric Oxide?

The researchers found that sunlight triggers your skin’s production of nitric oxide. Why is this significant? Because nitric oxide is crucial for maintaining healthy blood pressure, helps prevent atherosclerosis, and plays a role in modulating immune system function.

Your skin contains large stores of nitrite and nitrate, but only the nitrite is biologically active. Sunlight appears to prompt conversion of nitrate to nitrite and nitric oxide (NO). Please don't confuse nitric oxide (NO) with nitrous oxide (N2O) or "laughing gas," the anesthetic gas used by dentists.

Nitric oxide is such an important compound that it was dubbed “Molecule of the Year” by Science magazine in 1992, followed by the 1998 Nobel Prize in Medicine for its discovery as a signaling molecule in the cardiovascular system. Your blood vessels require the amino acid L-arginine for the synthesis of nitric oxide, since L-arginine is its precursor in your body.

By helping to regulate your blood pressure, nitric oxide enhances blood flow. Nitric oxide signals the smooth muscle cells in your blood vessels to relax so that your vessels dilate and your blood flows more freely, which helps your arteries stay free of plaque. When you have inadequate nitric oxide, your risk for coronary artery disease increases.

If your blood is flowing freely, then nearly every physiological process will function better. If your blood is sluggish, then important cells and nutrients can't reach the areas that need them. It's like getting the tow truck to the scene of the accident… no tow truck means no repairs.

Not only is nitric oxide important in regulating blood pressure, it also functions as a signaling molecule in your brain and immune system. Besides sitting in the sun, you can increase your nitric oxide levels with a few natural supplements and techniques:

  • Calcium and magnesium rich foods and supplements, and vitamins C and E
  • Olive extract
  • Bitter melon
  • Electrical acupuncture
  • Taking a warm bath, or by breathing in and out through one nostril (close off the other nostril and your mouth)

Uncontrolled High Blood Pressure, the SILENT Killer

According to the CDC, high blood pressure is the second greatest public health threat in the US. According to the CDC, 36 million people in the US have uncontrolled high blood pressure, and 14 million of them don’t even know it—quite alarming considering uncontrolled high blood pressure can be deadly when it results in a heart attack or stroke. But insufficient nitric oxide is just one factor contributing to the high blood pressure epidemic.

High blood pressure is associated with insulin and leptin resistance and elevated uric acid levels. One of the things driving up uric acid levels is overconsumption of fructose, and to a lesser degree, grains, beer and caffeine. Fructose breaks down into a variety of waste products, one of which is uric acid. Uric acid drives up your blood pressure by inhibiting nitric oxide in your blood vessels. In fact, 17 out of 17 studies demonstrate that elevated uric acid levels lead to hypertension.

According to the latest research, the safest range for uric acid is between 3 and 5.5 milligrams per deciliter, and there appears to be a steady relationship between uric acid levels and blood pressure and cardiovascular risk, even down to the range of 3 to 4 mg/dl. The ideal uric acid level appears to be around 4 mg/dl for men and 3.5 mg/dl for women.

Don’t Believe Everything You Hear About Melanoma

Melanoma is the most lethal form of skin cancer. However, your risk of dying from it pales in comparison to your risk of dying from cardiovascular disease, as discussed earlier. And the rates of melanoma so often quoted by government officials may be grossly inflated, based on recent data.

A report in the Journal of the American Academy of Dermatology5 claims that 90 percent of melanoma surgeries are actually unnecessary removals of benign lesions and not melanoma at all, raising questions about the accuracy of the “melanoma epidemic.” The lead author of the report attributed the unnecessary excisions to an increased awareness by patients who see anti-sun promotions, such as "melanoma awareness" campaigns, and worriedly run into clinics demanding treatment. The report highlights the necessity of getting a second, and perhaps even a third opinion from a specialized clinic before going under the scalpel.

Unfortunately, what this means is that, while the melanoma epidemic appears to be real if you go by surgical statistics, those stats actually paint a misleading picture if 90 percent of "melanoma cases" are not really melanoma! Sensible exposure to UVB light (adequate exposure without allowing your skin to burn) may actually protect you from melanoma, whereas UVA radiation is associated with skin damage. For example, indoor workers actually have a higher risk of melanoma than outdoor workers, suggesting that chronic sun exposure may indeed have a protective effect.

Melanoma studies are just now beginning to look at variables such as gender and affected body area. For example, one new Journal of Investigative Dermatology study found differences in skin cancer distribution patterns between men and women6. We need many more studies such as this before we can draw definitive conclusions about how the sun can increase—or decrease—your risk.

Basic Tips for Maintaining a Healthy Heart

Sunlight will provide enormous health benefits with respect to increasing your nitric oxide production, enhancing your vitamin D levels, and helping regulate your blood pressure, which in turn will reduce your overall cardiovascular risk. But you cannot stop there! You must also address other diet and lifestyle factors, starting with the basics.

  • Proper Food Choices
  • High-Quality Animal-Based Omega-3 Fats
  • Comprehensive Exercise Program, including High-Intensity Exercise
  • Optimize Your Vitamin D
  • Stress Reduction and Emotional Housekeeping
  • Avoid as Many Chemicals, Toxins, and Pollutants as Possible
  • Earthing, or Grounding Yourself to the Earth
  • Drink Plenty of Fresh, Pure Water Every Day
  • Get Plenty of High-Quality, Restorative Sleep

Editors note: This article has been updated to reflect Dr. Mercola's current views on vitamin D.


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