Previously in this series, the benefits of sunlight in the form of vitamin D production were discussed along with the ramifications of vitamin D deficiency. Along with vitamin D deficiency, another crucial benefit of sunlight (control of circadian rhythms) has been introduced. To top it all off, here’s another: sunlight on human skin increases nitric oxide in the bloodstream, which is important in regulating blood pressure and reducing risk of heart attack and stroke. Sunlight is essential to health.
The last post also introduced how UV-B radiation, which produces vitamin D, also leads to sunburn which many people believe leads to skin cancer. Three types of skin cancer and their accompanying statistics were reviewed, where it was posited that greater than 99% of all skin cancer cases are not fatal. 75% of melanoma cases, the most fatal of the three types of skin cancer, were shown to be present on parts of the body that are relatively unexposed to UV-B radiation (trunk and thighs as opposed to face and hands). Also, it was shown that melanoma rates have been increasing at an alarming rate over the past 30+ years, while UV radiation exposure rates have, on average, decreased for inhabitants of developed countries. The case was made that UV radiation alone cannot explain the massive increase in skin cancer. Something else must be at play.
It is illogical that a natural source of life-giving radiation (the sun), that we as human animals have been exposed to since the dawn of our species is now most commonly implicated as the source of a disease (skin cancer) that has only recently become proportionally common, while exposure to this radiation source has, on average, been decreasing.
The case has already been made that the sun’s radiation has not significantly changed, and yet we do see skin cancer rates increasing in developed countries. UV radiation has a role in the development of skin cancer, in that it does damage skin cells, but UV radiation has not changed. What has changed is the resistance of our skin to UV radiation. Skin that is the least prepared to receive the critically-important-for-health UV radiation will have the greatest risk of being sunburned, and have a greater risk of developing skin cancer.
As always, with anything health related, there is a context to healthy sunlight exposure. Sun exposure only becomes dangerous when intense sunburns become too easy. As mentioned in the previous post, after receiving a dose of UV radiation, some amount of damage incurs, and skin then produces melanin (read: a tan), which then protects the skin from further damage from UV radiation. Darker-skinned individuals already have high levels of melanin (known as constitutive pigmention), and thus are much less likely to burn to begin with. Thus, forming a tan is one way of preventing damage from UV radiation. Some individuals may be thinking “Well, I don’t tan, so there’s nothing I can do about it”, and there may be truth to that in extreme cases. However, most people can improve their ability to tan, and increase their resistance to the sun in general, with improved dietary practices and sun exposure behaviours.
This post will explore the combination of sun exposure, sunburn resistance and dietary habits that result in the benefits of sunlight exposure, while significantly reducing the dangers.
Sunburn Resistance Through Diet:It may surprise you that your resistance to sunburn can be influenced by your diet, but from my research and experiences I know this variable is significant. Unfortunately, there is no ‘magic-food’ that will instantly turn your skin into a suit of sun-blocking armour, but there are a few eating habits that can tip the scales in your favour and help you reap the benefits of sunlight exposure without getting fried. As implied in the last sentence, increasing your resistance to sunburn requires improvement in eating habits, so the results will take some time once the changes are made, but will be well worth it in the long run. According to Jean Krutmann and Philippe Humbert, authors of Nutrition for Healthy Skin, making these dietary changes will produce more sunburn-resistant skin in about 8 to 10 weeks.
So, where to begin? To start off, below is an infographic that summarizes everything I’ve found on this subject. Then, for the science enthusiasts, below that are all the nitty gritty details on the subject. Let’s hit it!