Sun, nutrition & the untold connections
Growing up, I remember my Mum telling me about her summers spent on the beach as a teenager, covered in baby oil and baking in the sun all day long, how things have changed! I grew up in a beach town and also spent summers in and out of the water. My mum was always into holistic health so unlike many other kids, she didn't slather me in sunscreen. She also made sure that I never got burnt.
It wasn't until I was older that I began to worry about the sun causing cancer. I always loved being in the sun, but started to worry if I'd already spent too much time under its rays. This is why I started digging around the science. I was shocked at what I found and not because of what other things that cause skin cancer, but because I'd never heard them mentioned.
I think it should be common knowledge.
The sun, your diet + your skin
What many blame on the sun solely can also be associated with a poor diet.
The standard American diet or the perfect acronym for it, 'SAD' which has travelled far and wide from America. It is full of toxic fats, cheese, too much meat, sugar and refined carbohydrates. The fats in these junk foods can be deadly, both for overall health and for skin cancer. Full of free-radical molecules that wreak havoc on the skin, and can make you more susceptible to skin damage and potential cancers of all kinds.
Polyunsaturated-fatty acids found in processed food damages our DNA and are linked to wrinkles and hyperpigmentation.
Processed foods are full of formaldehyde, coal tar derivatives, colour and flavour additives, and fluoride create reactions in our bodies that trigger collagen breakdown, inflammation, age spots, and hyper-pigmentation.
The SAD is full of all the foods you don't want and lacking the foods you do like, fruits and vegetables which protect all the tissues in the body, including your skin.
If you think about our long period of evolution, it has been normal for us to be exposed to sunlight. Until recently, it was normal for us to consume the nutrients necessary to prevent skin damage from food.
The dramatic change in our diet over the last hundred years, has come with a host of new health epidemics, all lifestyle-related. Placing skin damage solely on the sun is incredibly misleading. Adding high UV sun exposure (particularly if you've got fair skin and live in the Southern Hemisphere) to the mix of sugars, trans-fats, cheese, and meat is a recipe for disaster.
For example, one study shows that the very old diet, the Mediterranean, is associated with a lower skin cancer risk in women, particularly melanoma and BCC. And diets consisting of foods rich in vitamin D and carotenoids and low in alcohol are associated with a reduction in risk for melanoma.
I found this 2002 study in the Journal of Investigative Dermatology the most interesting. It looked at how UV exposure can create the ground work for skin damage because it depletes antioxidants in the body.
If you're not continually replacing those lost antioxidants through your diet it means your body can loose its natural defence against the sun.
Alcohol and skin cancer
While fruits and vegetables protect against sun damage, alcohol have been shown to dramatically increase your risk of sun damage. Multiple studies highlight the damaging effects of alcohol and your increased risk of skin cancer. One study has shown that people with a very high alcohol consumption have a 65% increased risk of melanoma.
In another study women were found to have a 250% increased melanoma risk among those who consumed two or more alcoholic drinks per day.
Yet another study demonstrated that women who consumed seven or more drinks per week had 64% greater risk of melanoma and a 23% greater risk of non-melanoma skin cancer when compared to non-drinkers.
We certainly have a culture in Australia where alcohol and sun go hand in hand, little wonder we also have one of the world's highest skin cancer rates.
Fluorescent light and skin cancer
Adding to the complexities of skin cancer are studies looking at blue light, environmental toxins and melanoma. One Swedish study showed a high correlation between melanoma and the jobs people do. Those professions exposed to more artificial UV plus environmental toxins had higher rates of melanoma. One of the more alarming studies that focused directly on fluorescent light exposure and melanoma discovered that fluorescent light exposure at work was associated with a doubling of melanoma risk. The risk grew with the increased duration of exposure to fluorescent light and was higher in women who had worked mainly in offices than in women whose main work was indoors but not in offices under fluorescent light.
Conflicting expert opinions
Not all dermatologists think that the sun is to blame for melanoma and skin cancers in general.
Dr Ackerman was an exceptionally distinguished dermatologist and one of the world's foremost authorities on the subject of skin cancer. Over his career he published more than 600 research papers.
Ackerman had a very different view on skin cancer and the sun. He did not believe that the link between melanoma and sun exposure was proven -
"While some studies do show a small association, he said, others show none." Taken as a whole, "the research is inconsistent and fails to make the case." And, the link between the sun and skin cancer the data simply "cannot demonstrate cause and effect."
He also didn't believe that sunburns sustained early in life, necessarily lead to cancer. A study of 966 patients looking at the effect of painful sunburns and lifetime sun exposure and it's effect on several types of skin cancer concluded that - "lifetime sun exposure is predominantly linked to an increased risk of squamous cell carcinoma (far less threatening form of skin cancer) and a lesser degree with two common types of basal cell carcinoma (the most mild form off skin cancer)." But by contrast, this study found that lifetime sun exposure appeared to be associated with a lower risk of the deadly malignant melanoma.
What is often left out by articles that reference Dr Ackerman is that he strongly advised that people stay out of the sun during high UV periods to avoid premature ageing.
Also, those who are fair skinned can prevent squamous cell carcinoma, by avoiding too much sunlight, particularly those of northern European descent living in the southern hemisphere.
Other knowledgeable researchers such as Dr Grant who heads the Sunlight, Nutrition and Health Research Centre in San Francisco largely agree with Dr Ackerman, however unlike Ackerman, Grant thinks some evidence does point to a link between sunlight and melanoma, but it's not a simple cause and effect relationship. When looking at melanoma many other factors need to be taken into account.While it is true that melanoma rates increase with increasing latitude, it is also true that even as far north as Canada, Denmark and the Netherlands, occupational exposure to solar UV radiation is associated with a reduced risk of melanoma. Conversely, for those of northern European ancestry living in the southern hemisphere, such as Australia, New Zealand and the US, melanoma rates are much higher than in their countries of origin. "Factors, including skin type and ethnicity, ancestral and geographic origin, all influence melanoma risk."
"To say that sunlight causes melanoma is at best an oversimplification and at worst a distortion of the scientific evidence."
Grant's most interesting thesis is that he doesn't think sunscreen is effective against melanoma and points out that sunscreens primarily block the shorter wavelength UV radiation when the longer wavelength UV poses a greater risk.
Connecting all the causal factors, it's a much bigger picture than simply thinking that by avoiding sunlight or using sunscreen, you'll be protected against melanoma. We should all be careful about how much sun we get depending on where we are, genetics and the time of year.
We should all be careful about how much sun we get depending on where we are, genetics and the time of year. Still, you also don't want to have an unhealthy relationship with the sun, for it is not the sole cause of cancer or skin ageing, and always wearing sunscreen and avoiding sun exposure is in no way optimal for your health.
In our last article, we'll look at how to interact with the sun intelligently.