Melanoma: The Scary Link Between Diet and Skin Cancer

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The Scary Link Between Diet and Skin Cancer

Skin cancer is now the most commonly diagnosed cancer in the United States and much of the world.

And you may not know it, but there’s a scary link between the sun, diet, and skin cancer (1).

This article will explain how the foods you eat can either enhance or significantly decrease your susceptibility to this increasingly prevalent disease.

What is Skin Cancer?

Firstly, there are three major types of skin cancer.

These are:

  • Basal Cell Carcinoma
  • Squamous Cell Carcinoma
  • Melanoma

Regarding basal cell and squamous cell carcinomas, these are the most common – and most curable – types of cancer.

However, the five-year survival rate can be as low as 17% for melanoma (1).

In this article, we are going to concentrate on melanoma.

What is Melanoma Skin Cancer?

What is melanoma skin cancer?

Melanoma is an incredibly aggressive form of skin cancer, and unfortunately, its incidence is quickly rising.

In fact, the prevalence of the disease has more than doubled since the 1980s and is predicted to increase further in the next 15 years (2).

In short, melanoma is usually a cancer of the skin that starts in melanocytes.

Melanocytes are the cells that produce the pigment known as melanin that we can see in skin color, eyes, and also moles.

While the majority of health advice to prevent melanoma revolves around avoiding the sun, recent research is showing that there is so much more to consider than that.

Sun Exposure and Skin Cancer: Is the Sun Deadly?

Sun exposure and skin cancer - is the sun deadly?

To begin with, we should note that there is a clear, strong link between sunburn and risk of melanoma. This fact is not in debate.

For one thing, a large body of evidence shows that a history of severe sunburn has close associations with increased melanoma incidence (3, 4, 5, 6).

Just to point out, this is specifically sunburning that is being discussed – not mere exposure to the sun.

In fact, I’ve always been a little suspicious about the advice to hide our skin from the sun completely, and liberally cover any exposed area with sunscreen.

After all, hasn’t the sun sustained human life for millions of years?

Similarly, this brings vitamin D into mind.

The key point is that vitamin D significantly reduces the risk for almost all chronic disease (including melanoma), yet widespread vitamin D deficiency exists in the public (7, 8, 9, 10, 11).

With this in mind, is there a possibility that some more recent changes in our lifestyle are causing the skyrocketing rates of melanoma?

Why have melanoma rates increased so significantly in the past few decades?

Does Bad Diet Promote and Cause Skin Cancer?

Does a bad diet promote melanoma skin cancer?

The link between diet and skin cancer is stronger than you may imagine.

In essence, there is a relationship between the food we eat, the sun, and skin cancer.

Also, there is a link between diet and skin cancer independently of the sun.

The Link Between Diet, Sun and Skin Cancer

Our skin has a certain amount of UV resistance naturally – we could call it a “natural sunblock.”

Depending on the food we eat, we can either dramatically strengthen or weaken this resistance (12, 13, 14).

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A significant example of this is the amount of polyunsaturated fats in our cells and our omega 3-6 ratio.

Both of these affect how stable our cells are and how resistant they are to oxidative damage from UV radiation.

To emphasize this point; a large body of evidence suggests omega-3 is an inhibitor of melanoma.

Conversely, the data implicate (excessive) omega-6 as a melanoma stimulator (15).

Given these points, we should choose the dietary fats we use carefully.

The Direct Link Between Diet and Skin Cancer

Different from the link involving the body’s interaction with sunlight, there is also a direct connection between diet and skin cancer too.

Chiefly, this relates to the way the food we eat can influence our body.

An example of this is that cancer cells can feed on glucose to grow, so a diet high in sugar may allow melanoma cells to grow more efficiently.

Modern diets excessively high in sugar and refined flours provide an abundant supply of glucose, providing the ideal environment for cancer cells to thrive.

Do Omega-6 Vegetable Oils Raise Melanoma Risk?

Do vegetable oils increase melanoma risk?

Despite their “heart healthy” marketing slogan, refined vegetable oils are not good for our body.

On the downside, there is also evidence showing omega-6 vegetable oils make our skin more susceptible to UV damage from the sun (16).

Additionally, omega-3 plays a beneficial protective role against sunburn due to its anti-inflammatory properties (17, 18)

It’s important to realize that the modern diet has a huge effect on these issues.

To begin with, throughout most of human history the omega 3:6 ratio was 1:1.

Shockingly, the average Western diet is now somewhere between 10:1 and 25:1 for omega-6 (19).

Worse still, both of these essential fats compete for uptake into our tissue (20, 21).

As a result, our body can not use enough omega-3.

Therefore, we miss out on its anti-inflammatory effects and protection against UV-induced damage.

How Do Vegetable Oils Cause Sunburn?

The first thing to remember is that when we consume fat, the different fats we eat compete for uptake into our cells.

Especially over the past few decades, dietary saturated fat and omega-3 intakes have fallen. At the same time, consumption of omega-6 has skyrocketed.

To put it another way; we have way more omega-6 stored in our skin’s cells.

Why is that bad exactly?

We should remember that omega-6 fatty acids are extremely susceptible to oxidation from heat and light (22).

Perhaps you have heard not to heat an oil too high, or that it should be kept in the dark? This advice is to protect the oil from oxidation.

This advice is to protect the oil from oxidation.

In the same manner, omega-6 fats are vulnerable to oxidize inside your body.

In other words; they are just as liable to oxidative damage inside or out of the body.

How Do the Sun’s UV Rays React With Omega-6?

Could omega-6 be the link between diet and skin cancer?

Now that we understand how unstable omega-6 is, we’ll look at what happens when it reacts with UV rays.

An interesting question no doubt, and one that researchers already came up with – and studied.

In this study, researchers fed hairless mice a variety of diets with increasing proportions of polyunsaturated fatty acids (PUFA).

The mice were then exposed to a chronic course of UV radiation to measure the results.

In general, the higher their dietary intake of PUFA, the more cancerous tumors the mice developed (23).

Interestingly, some mice were also fed a diet high in saturated fat in the study.

Comparatively, these mice had a much higher immunity to the UV radiation and didn’t develop cancer.

Summing up their findings, the authors suggested that their data suggests polyunsaturated fats enhance photocarcinogenesis (causation of cancer).

Going back to those omega ratio figures; most people have an imbalance of at least 10:1 omega-6.

Now imagine those people tanning themselves on the beach for hours, perhaps with a sense of false security because they have slathered themselves in sunscreen.

With this in mind, it’s not hard to see how fried foods and vegetable oils are contributing to the melanoma skin cancer epidemic.

Is a Lack of Polyphenols a Link Between Diet and Skin Cancer?

Is a lack of antioxidants a link between diet and skin cancer?

Oxidative stress (resulting in DNA damage) is a big player in the development of melanoma.

Like all cancers, free radical damage heavily influences skin cancer risk (25, 26).

Unfortunately, rapidly rising cancer rates probably go hand-in-hand with the plummeting nutritional value of the average diet.

The average person now eats processed foods full of cheap, industrial ingredients. In fact, 61% of all calories in the US come from ultra-processed food (27).

Compared to the diets of our grandparents, this is shocking. Our ancestors always ate freshly prepared meals from real homemade foods.

Now, many people order fast food or just make heavily processed microwave meals.

As a result, our intake of polyphenols and other beneficial nutrients has fallen by a lot.

How Do Polyphenols Prevent Melanoma Skin Cancer?

While it would be incorrect to say that antioxidants prevent melanoma, they may help reduce the risk.

Many antioxidants found naturally in food “have demonstrated clear anticancer effects toward melanoma” (28).

Free radicals damage our body and antioxidants help protect it.

In other words, your dietary choices either help prevent disease or allow it to take hold.

What Causes Free Radicals?

Here are a few common contributors to free radicals in the body:

  • Excessive exercise
  • Lack of sleep
  • Eating oxidized fats
  • Sugar and excessive carbohydrate
  • Stress
  • Pesticides and herbicides
  • Excessive exposure to UV light.
  • Other exposure to environmental or dietary toxins.

Where Can We Get Polyphenols?

Essentially, if you eat a diet full of fresh, whole foods, you will be consuming an adequate amount of polyphenols.

Usually, we can get these compounds in the greatest amount from plant foods – or foods that came from a plant.

A few common examples are fruit, vegetables, cacao, coffee, tea, and red wine.

Balanced Omega 3:6 Ratio Protects Against Melanoma

Balanced omega 3:6 ratio protects against melanoma

Balancing the omega 3-6 ratio is one of the first dietary steps to reduce melanoma risk.

In fact, it’s one of the first things you should do to minimize the risk of any disease.

To do this, here’s what you want to do:

  • Remove vegetable oils high in polyunsaturated fats (check here)
  • Avoid fried food in restaurants
  • Eat fatty portions of fish at least three times per week (salmon and mackerel are both excellent)
  • Check labels to make sure there are no vegetable oils.
  • Preferably stop buying processed foods and emphasize real, fresh food from local markets.
  • Don’t go crazy on natural foods high in omega-6 fats (e.g. nuts – a handful is enough).

A diet to help prevent melanoma – or any skin cancer – will have three things in common.

Specifically:

  • It will contain zero or very small amounts of omega-6 vegetable oils
  • There will be plenty of nutrient-dense foods consumed
  • The diet will include sources of omega-3

In my mind, these are the big three in the link between diet and skin cancer.

5 Antioxidant-Rich Foods That Protect Against Melanoma

Antioxidant-rich foods that help reduce melanoma risk

Here are five especially important foods and drinks that help strengthen the skin’s resistance to UV, reduce sunburn and protect against skin cancer risk.

  • Salmon: Salmon firstly contains omega-3, which as we have discussed is extremely beneficial for strengthening the skin. Secondly, salmon contains a potent antioxidant called astaxanthin. In studies, “astaxanthin exhibited a pronounced photoprotective effect and counteracted all of the measured UVA-induced alterations to a significant extent” (29).
  • Tomatoes: Tomatoes are another of the foods protective against skin cancer. Tomatoes contain lycopene, a vital antioxidant. A study investigated the results of a daily (40g) serving of tomato paste over ten weeks against a control group. Although there was no difference after 4 weeks, the tomato paste group had a 40% better resistance to UV radiation at week 10 (30). This progressive improvement is also a good reminder; we should get into healthy dietary habits every day, not just occasionally! Good health is a continuous journey.
  • Dark Chocolate: You may not know it, but cacao is one of the most nutrient-dense foods in the world. Long-term consumption of cocoa increases our skin’s UV resistance (31, 32).
  • Tea: Both green and black teas offer an excellent range of antioxidants that help reduce the risk of sunburn. Black tea appeared to show a protective effect against melanoma in a study from Italy, whereas fruit and vegetables did not (33). Additionally, numerous studies report that green tea reduces cancer risk (34).
  • Coffee: As the biggest source of antioxidants in the modern American diet, coffee has a wealth of health benefits (35, 36). Furthermore, research shows that coffee could play a significant role in the link between diet and skin cancer. Several studies demonstrate a “statistically significant” inverse risk to melanoma (and all skin cancers) in coffee drinkers (37, 38, 39, 40).

Final Thoughts

In the long run, there are lots of things that can increase or reduce our risk of skin cancer.

These include sunburn, getting enough sunshine (vitamin D is necessary!), and as with any cancer; focusing on healthy living in our everyday lives.

The link between diet and skin cancer is strong, though.

The main points to remember are keeping an optimal omega 3:6 balance and emphasizing nutrient-dense foods on a daily basis.

23 COMMENTS

  1. Excellent stuff!
    I’ve noticed for a while now that I don’t burn anymore on LCHF.
    I have my own personal theory that it had something to do with a change in the fat constitution of my skin.
    This article supports that 🙂

    • Salmon can do – especially farmed fish. If you can get wild salmon (Alaskan) then that’s the best bet. Freshwater trout is also similar nutritionally, clean, and has a comparable taste. Generally, animal-based omega-3 products are much better for EPA than plant-based omega-3s.

  2. My skin specialist, that I go to once a year seems to have known all about the link between Melanoma and Omega 6 for a long time. She also knows about polyunsaturated oils being bad for our bodies and told me to sit in the sun, especially in the winter for at least 45 minutes.
    When I asked her how she knows these facts, she said she attends updating lectures for skin specialists once a month.
    My own doctor, on the other hand can’t see anything wrong with seed oils and doesn’t want to know about the LCHF diet I eat. He only said to me that he doesn’t know what I am eating, but to keep it up!!!

    • That’s great that you have a skin specialist who’s up-to-date with all the latest research.
      I also think many doctors are the same, and the nutrition advice most give is not really optimal in my opinion.

      We can’t really blame them though when most doctors only study a short module on nutrition. Maybe one day healthcare will focus on prevention rather than drugs, cures, and medicine!

  3. This is fascinating! I am very fair skinned and being from Southern California, I have had many sunburns. I thought I noticed in recent years (I’ve been LCHF for three years)) that I don’t burn the way I used to. In the past, comparatively low sunlight exposure resulted in burns, but I haven’t experienced that in quite a while.
    What about olive oil? It’s not primarily polyunsaturated, but it does seem to oxidize at high heats.

    • Your experience is not an isolated one! Many people see the same thing when going lower carb and cutting out PUFA oils.

      I would say extra virgin olive oil would provide a net protective effect, especially given all the polyphenols it contains.

      Also, olive oil is actually a lot more heat-resistant than most people realize; you can see some studies on this in the section on olive oil here: http://nutritionadvance.com/best-oil-for-deep-frying

  4. Great article! I was pretty frustrated after visiting a new Cancer prevention website in Alberta, Canada (www.albertapreventscancer.ca) that pushes sunscreen all the time – make sure to even cover your lips! – and they are referencing studies that show the relationship between excess sun exposure and a diet high in red meat as increasing your risk for cancer. I don’t understand how they can be so far behind. Like you said (and I’ve always thought), we’ve existed with the sun for millions of years! Is enjoying the sun supposed to be some kind of guilty pleasure?! It’s natural to want to be out in it!
    Here are links – they even advertized on TV:
    “Use sources of vitamin D that are safer than UVR exposure, e.g., dietary sources, including fortified foods, and vitamin D supplements. Intentional UVR exposure to meet vitamin D requirements is not recommended.” http://www.albertapreventscancer.ca/reduce-your-risk/limit-uv-rays/sun-safety/

    “Many studies have found a link between eating a lot of red meat (e.g. pork, beef and lamb) and eating processed meats (e.g. ham, bacon, salami, and sausage) and developing colorectal cancer.”
    http://www.albertapreventscancer.ca/reduce-your-risk/eat-healthy/

    • Thanks! Well, if we look at it in a cynical way, then fear of the sun makes money! And is there a difference in the findings between industry-funded studies and independent studies?

      I don’t disagree that the sun can be dangerous – but avoiding it and covering every inch of our body is, in my opinion, rather silly.
      It also ignores the fact that sunlight contains a lot more beneficial compounds than only vitamin D.

    • Hi Scott,

      I’m sorry to hear about that.

      There is a really good write-up providing insight into the referenced study by researcher George Henderson at http://hopefulgeranium.blogspot.co.uk/2017/01/will-ketogenic-diet-increase-risk-for.html

      To sum up: more research is needed, but it seems that very low carb diets may help reduce risk…but possibly aren’t a good idea for treatment.

      I think the best thing to do is to speak to a specialist/oncologist you trust about this issue, who should (hopefully) be aware of all the latest research.

      Hope everything goes well.

      • Thanks for getting back to me. I found some more information regarding the Xia et al study and the implications for people wanting to try a primary fat diet who suffer from melanoma , titled “BENEFICIAL EFFECTS OF KETOGENIC DIETS FOR CANCER PATIENTS – A REALIST REVIEW WITH FOCUS ON EVIDENCE AND CONFIRMATION Rainer J. Klement – The study of Xia et al. [66] showed that acetoacetate, but not BHB, accelerated tumor growth of BRAF V600E peer expressing melanoma xenografts, which led the authors to express concerns about KDs for patients with tumors that harbor such mutations. However, in this study a KD did only increase acetoacetate, but not BHB levels, which makes this KD appear different from all other animal experiments and questionable as a model system for a KD applied to humans where ketosis is characterized by more than four-fold lower acetoacetate than BHB levels [117]. It is also noteworthy that the best response to a KD in the study by Tan-Shalaby et al. [17] was seen in a patient with BRAF-V600 positive stage V melanoma who stayed tumor-free after surgery and a prolonged KD at 131 weeks of follow-up.”

  5. I also have noticed that I stopped burning easily in the sun, and from accidental heat burns as well, with a huge reduction in blisters, when I cut out vegetable oils and replaced them with (mostly) animal fats and some olive and coconut oils. I still eat foods like chicken and pork and nuts, so I don’t think my omega-6 is super low. I think it’s likely that lowering what were elevated insulin levels might also have something to do with this protection as hyperinsulinemia relates to various changes in the skin such as acne and skintags, but how this affects burning I have no idea.

    • This is basically my experience too. I used to get burned despite suncream, and a few times quite badly too. Probably due to staying in the sun too long since I thought I was protected.
      Since cutting out sugars and veg oil, I can go out in the sun for 3 or 4 times longer without having to worry. Still can’t believe the difference sometimes!

      • To me the immunity to heat blisters is a compelling, and easily testable phenomenon. Might be hard to get ethics approval for burning people though. I used to get blisters on a monthly basis from accidental burns, since going LCHF and throwing out vege oils I’ve had one small blister in 5 years. Last year I touched a barbecue plate with my finger thinking it was too cold when it was fully hot, got a burn but a day later no blister, skin healed. It’s easy to tan without burning in summer and though I don’t push my luck accidental overexposure doesn’t have consequences any more.
        I’ve found some evidence here in an RCT of a low fat diet that would have restricted PUFA
        http://www.nejm.org/doi/full/10.1056/NEJM199405053301804#t=article
        And some for omega 3 here
        http://ajcn.nutrition.org/content/89/4/1246.full

        • Yes, an RCT of burning people sounds more like torture!

          Thanks for the studies – will take a look at them now.

          I noticed the same thing about tanning too – much easier to go brown without any accidental burns. It’s a really nice benefit!

  6. Just one comment about fish………I was reading David Gillespie’s book “Toxic oils” and he mentioned that any farmed fish is also high in omega 6……..like grain fed cattle, farmed fish are fed a diet high in soy products and grains, which are themselves high in omega 6.
    So I only eat wild caught fish and grass fed cattle. Like our ancestors did…….real food.
    And, since going LCHF, my skin doesn’t burn easily in the sun.

  7. Thanks for your kind reply, Michael, and the link.
    Wow……..that is a great article. So glad we chose to get the wild salmon. It’s frozen of course, being from Canada, but fortunately, we can afford it. But, as you say…….farmed fish is probably better than no fish.

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