When the weather heats up, we say goodbye to heavy layers and get the summer wardrobe out of storage. But while tee shirts, shorts and bathing suits can keep us cool and comfortable when the mercury hovers around 90, they don’t offer much in the way of protection from the damaging rays of the sun. And that’s a problem that’s literally skin-deep. 

At a glance: Your largest organ

The skin is the largest organ of the body, and it has many important functions: it is a protective barrier keeping out microorganisms and harmful substances, helps regulate body temperature, and transmits the sensations of touch, heat, and cold to the brain. Protecting the skin from ultraviolet (UV) light helps keep your skin healthier and reduce the risk of skin aging and skin cancer. 

It’s not all sunshine and roses

Sunshine is essential to our health and wellbeing, but it also has a dark side.  Exposure to sunlight, especially early in the morning, is vital for regulating our sleep cycles and elevating our mood. But the problem is that too much sun is a major culprit in causing skin damage, so we must be wise in how we enjoy being outside. 

A good defense is your best strategy

Shade and sunscreen provide vital protection. Being outdoors without adequate sun protection can cause serious harm, ranging from a painful sunburn to skin cancer. Melanoma, the deadliest form of skin cancer, has been steadily on the rise since the 1970s. Although the rise has slowed in recent years, melanoma is still increasing. 

Since 2005, melanoma incidence has risen at a rate of 1.1 percent per year.1 About half of young adults (age 18-29) report getting at least one sunburn per year.2 This is a worrying statistic, because every sunburn increases your skin cancer risk. 

Related: 6 Ways to Boost Your Mood This Winter

Sources:
National Cancer Institute. Surveillance, Epidemiology, and End Results Program (SEER). Fast Stats
Prevalence of Sun Protection Use and Sunburn and Association of Demographic and Behaviorial Characteristics With Sunburn Among US Adults

Sun exposure causes skin aging

In addition to sunburns and skin cancer, it’s estimated that up to 80% of visible skin aging is due to sun exposure.³ A randomized controlled trial in Australia assigned 903 women under the age of 55 either to use SPF 15 sunscreen on their face, neck, arms, and hands every day, or to use sunscreen or to use sunscreen at their discretion. The subjects were followed for four years, and the two groups reported similar sun exposure.

At the end of the four-year trial, the women in the daily sunscreen group were 24% less likely to show a detectable increase in skin aging over four years.⁴

Sources:
Effect of the sun on visible clinical signs of aging in Caucasian skin
Sunscreen and prevention of skin aging: a randomized trial

Enjoy being outdoors safely

Spend much of your outdoor time in the shade

Headed to the beach? Spend your non-swimming time under an umbrella or in a beach chair with a built-in shade. But be careful if you’ll be outside all day: different materials provide different levels of sun protection, and the UV rays reflect off the sand. You may still need to wear sunscreen under the umbrella.^5,6

Wear protective clothing 

Wear a wide-brimmed hat, long sleeves, and long pants when you’re in the sun. Look for lightweight clothing with UPF (ultraviolet protection factor) ratings for your outdoor adventures. Remember to protect your eyes with sunglasses. 

Avoid the strongest UV rays

If you are going to spend time in the sun, avoid the highest-risk time of day, 10 am to 2 pm, when the sunlight is the strongest. Limit your total time in the sun. And, of course, don’t use tanning beds. 

Choose a safe and effective mineral sunscreen 

See my guidelines below, and apply a generous amount of sunscreen. 

Don’t rely on sun exposure alone for your vitamin D needs 

It’s not worth it to increase your risk of skin cancer and skin aging by exposing your unprotected skin to sunlight when a safer alternative – supplementation with D3 – is readily available. 

Related: Vitamin D is Crucial to Overall Health

Eat carotenoid- and flavonoid-rich foods

The benefits of eating a Nutritarian diet extend to all aspects of your health. Research has shown that consuming carotenoids limits oxidative damage to the skin from UV exposure, which could contribute to prevention of sunburns and skin cancer.^7-10 Studies have found similar results for green tea flavonoids.¹¹ These foods will not replace sunscreen, but they’ll give your skin some supplemental protection from UV damage. 

Sources:
Beach Umbrella vs Sunscreen With a High Sun Protection Factor: A Randomized Clinical Trial
The role of phytonutrients in skin health
Beta-carotene and other carotenoids in protection from sunlight
Tomato paste rich in lycopene protects against cutaneous photodamage in humans in vivo 
Tomato Phytonutrients Balance UV Response: Results from a Double-Blind, Randomized, Placebo-Controlled Study
Green Tea Catechin Association with Ultraviolet Radiation-Induced Erythema: A Systematic Review and Meta-Analysis

Guidelines for choosing a safe sunscreen

Remember that no sunscreen prevents all UV rays from harming your skin. UVB rays cause sunburn, and both UVA and UVB rays contribute to skin cancer. Many sunscreens do not protect against UVA rays. The Sun Protection Factor (SPF) listed on sunscreens refers only to UVB protection. The Food and Drug Administration (FDA) requires sunscreens to be tested to determine whether a product can be labeled “broad spectrum,” meaning that it protects against UVA and UVB rays. The FDA recommends applying a broad spectrum sunscreen with an SPF of at least 15 to help prevent skin cancer.¹² 

Avoid sunscreens with vitamin A (retinol or retinoids)

Vitamin A is often listed on sunscreen labels as an antioxidant that can fight skin aging. Vitamin A is an antioxidant, but there is disagreement over whether topical vitamin A increases the sensitivity of the skin to sunlight.

Choose mineral sunscreen ingredients

Mineral sunscreens contain titanium dioxide, zinc oxide or a combination of the two, and these are preferable to the chemical sunscreens currently available in the United States. These minerals absorb UV rays, preventing damage to the skin beneath.¹³  Zinc oxide has been found to be superior to titanium dioxide in absorbing UVA rays.¹⁴ 

The chemical sunscreen ingredients oxybenzone and OMC (octyl methoxycinnamate or octinoxate) are are endocrine disruptors – chemicals that have the ability to mimic, inhibit, or alter the action of the body’s natural hormones.¹⁵ A study by the Centers for Disease Control and Prevention found oxybenzone in the urine samples of 96 percent of the Americans tested; this suggested that oxybenzone is absorbed into the blood when chemical sunscreen is applied to the skin, and could therefore disrupt hormones in the body.¹⁶ 

Absorption of chemical sunscreen ingredients was confirmed by a 2019 study by scientists at the FDA on avobenzone, oxybenzone, octocrylene, and ecamsule. They reported that these chemical sunscreen ingredients are detected in the blood within hours of application, and that the concentrations of these ingredients in the blood exceed the level set by the FDA that would require additional toxicology studies to determine whether they are safe.¹⁷ 

Related: Chemical sunscreens are even worse than we thought

Another study by FDA scientists in 2020 examined absorption of six sunscreen ingredients: avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate. The findings agreed that these ingredients were systemically absorbed, and blood concentrations exceeded the FDA’s threshold requiring additional safety studies.¹⁸ 

The conclusion from these studies was that there is not enough research to assure the safety of chemical sunscreen ingredients. The FDA considers zinc oxide and titanium dioxide the only sunscreen ingredients generally recognized as safe and effective.^17,19

Sunscreen ingredients can also enter directly – into oceans or lakes when people swim – or indirectly, through wastewater. There is preliminary evidence that some sunscreen ingredients, such as oxybenzone, could harm coral reef ecosystems.^20,21 In 2021, Hawaii banned the sale of sunscreens containing oxybenzone or octinoxate because of their potential harms to coral reefs.

Sources:
Metal oxide sunscreens protect skin by absorption, not by reflection or scattering
Microfine zinc oxide is a superior sunscreen ingredient to microfine titanium dioxide
Sunscreens: are they beneficial for health? An overview of endocrine disrupting properties of UV-filters
Concentrations of the sunscreen agent benzophenone-3 in residents of the United States
Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial
Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial
Food and Drug Administration. Proposed rule: Sunscreen Drug Products for Over-the Counter Human Use
Investigating the exposure and impact of chemical UV filters on coral reef ecosystems: Review and research gap prioritization
A Critical Review of Organic Ultraviolet Filter Exposure, Hazard, and Risk to Corals

Choose non-nano sunscreen

Certain products use nanoparticles of titanium dioxide and zinc oxide to make the sunscreen more easily absorbed by the skin and more transparent. Sunscreen labels often do not disclose whether the product contains nanoparticles. There have been concerns that these small particles could penetrate the skin and enter the bloodstream. 

The available evidence suggests that zinc nanoparticles do not penetrate the skin. Zinc oxide nanoparticles likely do break down while on the skin surface, which could lead to zinc alone penetrating into deeper layers of skin and possibly entering the circulation. However, this exposure to zinc most likely would not have harmful effects.^22-25 

Most studies in humans found no penetration of the skin by titanium dioxide nanoparticles, whereas at least one found very low levels of absorption of titanium dioxide nanoparticles from sunscreens.^26-28
There is some evidence that nanoparticle-size zinc oxide and titanium dioxide might generate oxidative stress in the skin, and that they could have detrimental effects on marine life, including corals.^26,29

Sources:
Human skin penetration and local effects of topical nano zinc oxide after occlusion and barrier impairment
Relative Penetration of Zinc Oxide and Zinc Ions into Human Skin after Application of Different Zinc Oxide Formulations
Human Epidermal Zinc Concentrations after Topical Application of ZnO Nanoparticles in Sunscreens
Support for the Safe Use of Zinc Oxide Nanoparticle Sunscreens: Lack of Skin Penetration or Cellular Toxicity after Repeated Application in Volunteers
A review of inorganic UV filters zinc oxide and titanium dioxide
Titanium Dioxide Nanoparticles in Food and Personal Care Products-What Do We Know about Their Safety?
Repetitive Application of Sunscreen Containing Titanium Dioxide Nanoparticles on Human Skin
Environmental Fate and Toxicity of Sunscreen-Derived Inorganic Ultraviolet Filters in Aquatic Environments: A Review

Avoid spray sunscreens – even if they’re made using mineral ingredients

The FDA is investigating whether sunscreen sprays are adequately effective, and it’s unclear whether sunscreen ingredients – including titanium dioxide – pose risks if inhaled.^30-32 Plus, the sprays may not coat the skin evenly or thickly enough. Until this is clarified, all sunscreen sprays, whether chemical or mineral, are best avoided. 

Sources:
FDA: Stay Safe in the Summer Sun
Titanium Dioxide (TiO2). International Agency for Research on Cancer
No evidence for carcinogenicity of titanium dioxide nanoparticles in 26-week inhalation study in rasH2 mouse model

My recommended sunscreen

I recommend and make available a safe and effective sunscreen line that uses nonmicronized zinc oxide. Kabana Green Screen® organic broad spectrum sunscreen protects against both UVA and UVB rays without the use of nanoparticles or harmful chemicals. It is made from all natural and edible grade organic ingredients, and uses non-nano zinc oxide, the sun protection ingredient with the best evidence for safety and effectiveness. 

Of all the mineral sunscreen products, Kabana Green Screen® is one of the very few that does not contain nano- or micro-sized particles. Before I decided to endorse Kabana Green Screen®, I contacted and communicated with the technical departments of many sunscreen companies to find a product that does not contain nanoparticles.