The Sun A Friend And A foe
Did you know that all life on our beloved planet is solar powered? One way or another, all energy on earth comes from the sun. Direct sunlight is essential to sustaining life and vitality for both animals and plants. We humans depend on the sun to manufacture vitamin D in the skin. But, you may also be aware that direct sunlight, more specifically radiation from the sun contributes to skin damage, aging and skin cancer. So, how do we go about maintaining balance and getting just enough sunlight for health and vitality while staying safe?
Let us discuss various approaches to sun safety and specifically delve deep into the use of sunscreens. We will answer questions such as: What sunscreen options are available? How effective are they? Do dark skin people need it? What is SPF all about?
Why must you protect yourself from overexposure to the sun?
In addition to visible light, the sun also sends radiation (energy waves) to our planet. Ultraviolet (UV) rays in the form of ultraviolet A (UVA) and ultraviolet B (UVB) make up part of these energy waves.
UVA rays are subtle in action, yet devastating in effect. While they won’t cause sunburn, over time, they cause; premature aging of the skin, the appearance of wrinkles, sagging, and leathering. Furthermore, they contribute to the development of skin cancer. On the other hand, UVB rays are the culprit when it comes to sunburn, and of course, they also contribute to skin cancer.
So, the reason you must protect yourself from overexposure to the sun is to keep your skin youthful and prevent potential skin cancer. As you might already be aware, there are numerous recommendations for doing this. One way is by using sunscreen.
What is Sunscreen?
Sunscreen offers protection against UVA and/or UVB. It was previously also referred to as sunblock, although this term is no longer used on U.S products.
familiarizing yourself with some of the most common ingredients used is the easiest way to get a handle on these products. Over and above that, you will be well served to know the safety profile of these products. Here is a shocker; some ingredients used in sunscreen may, in fact, fuel skin cancer.
Common Ingredients Used in Sunscreen.
The Environmental Working Group (EWG) published a comprehensive report on the state of sun-protecting products in the U.S in 2018. This report states that as many as to 67% of sunscreens on the market may not work or they may actually be harmful. Let us take a look at some of the ingredients and decide on what to use and what to avoid.
There are many ingredients used in these products. It’s a chemical forest that’s not easy to navigate. This is made worse by the burgeoning industry of skincare products in general. So let’s simplify this. Most active ingredients can be grouped into one of two categories; ‘Chemical’ or ‘Mineral’. To this end, sunscreens may be chemical, mineral or a combination.
Generally, mineral sunscreens rate safer than their chemical counterparts, although of course like anything else they have their downsides.
Chemical Sunscreens and SPF
They protect our skin by absorbing UVB radiation. I am sure we have all seen the letters SPF on sunscreen and other cosmetics. What does it mean? It stands for Sun Protection Factor. SPF measures how well a sunscreen cream interrupts UVB rays. Without getting too technical, SPF is actually a ratio of the time it takes to get sunburnt with sunscreen applied to the time it takes without sunscreen. There are no exactitudes; we are dealing with approximations since burn time depends on many other factors.
Thus, if you experience sunburn after 150 minutes with sunscreen applied versus only 10 minutes without, the SPF is calculated as 150/10, which gives us 15. As noted above, this is a feature of chemicals that absorb UVB only. We shall see shortly about UVA.
So what SPF value is best?
Is it 15, 30, 50 or higher? Current recommendation put SPF 15 as the minimum. You may choose to go as high as SPF 50. Any higher than this you start to get diminishing returns, that is, a lot more SPF increase yields little-added protection. Your choice will also depend on your skin type and other factors, for instance, patients with lupus may need SPF 30 or higher on account of increased sensitivity to sunlight.
In a nutshell, some ingredients used in chemical sunscreen may cause hormone imbalance and allergic reactions:
- Oxybenzone was found to lead to abnormal sperm function in animal studies and a condition called endometriosis in women. Furthermore, it is a skin allergen.
- Octocrylene and methylisothiazolinone are also classified as skin allergens.
- Octinoxate (Octylmethoxycinnamate): In animal studies was found to affect reproduction, thyroid function, and behavior.
- Homosalate, like oxybenzone, is a hormone-disruptor, affecting estrogen, progesterone, and androgens.
- Retinyl palmitate is another interesting ingredient; it is a type of vitamin A. It is usually added to some sunscreens as an anti-aging agent, helping to reduce wrinkles. Animal studies show that it may possibly lead to skin tumors and accelerate cancer cell growth by 21%.
The above list is by no means exhaustive, for an in-depth look at these chemicals, please refer to the EWG report.
You must prudently note several points though, one, most of the above-mentioned effects occur on animal subjects. Two, the type of exposure to these chemicals is different for animals. The chemicals are not administered topically. Lastly, the relative dose in humans is different compared to that in animals. Suffice to say, this is what is known concerning the above ingredients.
Unlike chemical sunscreen, ingredients used in mineral sunscreen do not absorb UVB radiation. Instead, they offer protection by ‘blocking’ UVA radiation. SPF cannot be used to measure their effectiveness. Unfortunately, at this time we do not have a measure of UVA absorption in commercial use. So then, how do you know if a sunscreen will protect you against UVA if one cannot rely on SPF? Well, you have to know the ingredients that absorb UVA.
These ingredients are considered to be relatively safe for us compared to their chemical counterparts. You must, however, be made aware of a few reservations. The most important is that these sunscreens often contain nanoparticles. These are very small, microscopic particles that may potentially be inhaled. They have not yet been stringently studied for long-term impact on human health. The common ones include;
- Titanium Dioxide
- Zinc Oxide
What sunscreen is best for you?
The perfect sunscreen does not exist. There are however safe options to choose from. Moreover, recognize the importance of using other alternatives of sun protection, as noted later, in addition to sunscreen. For specific brand alternatives, please refer to the EWG report. It provides a list of safe and affordable options available in the U.S. But, in general, go for a broad-spectrum sunscreen that protects against both UVA and UVB radiation with an SPF of at least 30. Always reapply the sunscreen after 2 hours as it wears off. If sweating or going swimming, reapply hourly.
Will sunscreen help in sun damaged skin?
Sun damaged skin will usually show with sunspots. These are areas of increased pigmentation, most common in light-skinned people. Sunscreen in conjunction with other protection strategies will help to prevent further damage and allow the spots to slowly fade.
Do dark skin people need sunscreen too?
Yes! You must know that people with dark skin can also develop skin cancer, especially on the palms and soles. Compared to light-skinned individuals, their risk is lower. Also, prolonged exposure to UV radiation contributes to skin aging, hence sunscreen is of benefit to dark skin too.
Will using sunscreen interfere with Vitamin D?
Yes, slightly. The body requires UV radiation to manufacture vitamin D as noted earlier. But don’t be worried, there are ways around this. For instance, you may apply your sunscreen after 15 minutes of being in the sun. This will allow you enough UV radiation to manufacture this important vitamin.
Other strategies for sun protection
Please bear in mind that sun protection is more than just sunscreen. You must view sunscreen as an important part of a much larger picture. In fact, in the absence of any definitive empirical evidence, it is debatable as to whether sunscreen prevents skin cancer. We do however have other recommended measures that you must adapt to maximize protection. They are as easy as wearing a hat, here they are;
- Find Shade: the time from 10:00 AM to 4:00 PM is generally when the sun rays are most harsh. As a rule of thumb, if your shadow is shorter than you, you should be under a shade.
- Use protective clothing and sunglasses: Stick to long sleeves whenever possible and wear hats. Choose sunglasses with 99-100% UV absorption.
- Avoid recreational sunbathing.
- Avoid the use of use sunlamps and tanning beds.
- The weather report often includes a UV index. This number indicates how severe or damaging the sun will be on that day. Beware an index of 10 or more.
- There are certain medications that may make your skin more sensitive to sunlight. Examples include certain antibiotics, antifungals, chemotherapies and blood pressure medications. Make sure to find out from your doctor.
- Maintain a well-balanced diet to continuously nourish and restore the skin.
Take Home points on sun protection and Sunscreen
- When choosing a sunscreen, be vigilant and understand the ingredients used.
- Select a broad-spectrum sunscreen that will offer protection against both UVA and UVB radiation.
- If possible, go predominantly mineral sunscreen instead of chemicals like dioxybenzone, etc.
- Be wary of false advertising and understand claims like ‘water-resistant’ and ‘sweat-resistant’
- Keep it simple by using other forms of sun protection such as clothing.