Vitamins and Skin Cancers
Vitamins and Skin Cancers…can your diet help protect you from skin cancers? Let’s look at the A, B, C, D and E’s of skin cancer protection…
Sun protective clothing, a wide brimmed hat, sunglasses, sunscreen had all work very well for protecting the skin from the dangers of the Australian sun, however, some people who spend hours in the direct sun every day might benefit from a little more protection than physical barriers to help combat their risk of skin cancer.
Vitamin A has been linked to lowering skin cancer in a large study of more than 125,000 people in America. There are many established benefits of vitamin A including protecting your eyes from age related decline, supporting a healthy immune system and bone health. A recent study published in the JAMA Dermatology journal found that there is an inverse association between consuming vitamin A and the risk of cutaneous squamous cell carcinoma. What this means it that for people who ate the recommended amount of vitamin A there was a 15% lower chance that they would develop Cutaneous Squamous Cell Carcinoma.
Cutaneous SCC is a type of non-melanoma skin cancer and one of the most common forms of the disease after Basal Cell Carcinoma in Australia. While not as dangerous as melanoma, it has been known to spread to other parts of the body from the skin and pose significant risk.
The best source of vitamin A is from a balanced diet filled with fruits, vegetables and healthy animal products. Some foods with a high percentage of vitamin A include: liver from beef, lamb or other sources, cod liver oil, fish such as salmon, mackerel and tuna, cheeses such as goats cheese, cheddar and camembert.
It is important to note that too much vitamin A can have negative consequences on the body. The recommended amount of vitamin A per day is between 700 and 900 micrograms, exceeding this can cause liver damage, thinning of the bones and osteoporosis.
Thus, natural sources of vitamin A are a much better solution than supplements for getting the amounts of vitamin A that you need. The 2019 study conducted over 25 years showed that people who took vitamin A supplements did not appear to have a lower chance of developing SCC. Thus, eating the right foods and having a balanced diet is the best way to get the vitamin A you need to fight the risk of skin cancer.
While it is great news about vitamin A and its impact on reducing the risk of skin cancer, we need to understand that the right amount of vitamin A in your diet still cannot replace more traditional forms of protecting your skin against the sun. When going outside, particularly on days with a high UV index, it is still important to wear sunscreen, slip on long sleeved, protective clothing and wear a hat that will cover the face, neck and ears.
Cancer Council NSW helped fund one of the biggest discoveries in skin cancer research – that vitamin B3 can help reduce non-melanoma skin cancers. Five years after this grant ended, we review what the lead researcher, Professor Diona Damian said about her pioneering work.
It all began in 2008, when Cancer Council NSW awarded a research grant to Professor Diona Damian and her team at the University of Sydney. Over the next three years, the researchers led the way globally in exploring a new approach to tackling skin cancer.
“We were interested in finding new ways of preventing and treating skin cancer, because that’s our national cancer. It’s the most common cancer in Australia, more than four times as common as all other cancers put together”, Professor Damian said.
When Professor Damian’s team began their work, they knew that even low doses of UV radiation from the sun could cause skin cancer. UV radiation does this not only by damaging the DNA in skin cells, but also by suppressing our skin’s immune defences. Professor Damian had already tested a number of compounds which could potentially prevent this sunlight-induced immune suppression, and found that a form of vitamin B3, called nicotinamide, had the greatest potential.
Thanks to Cancer Council NSW funding, her team was able to prove that nicotinamide, either as a topical lotion or a daily tablet, is highly effective in providing immune protection. Nicotinamide does this by replenishing cellular energy, which also enables faster and more efficient DNA repair following sun exposure.
A LANDMARK CLINICAL TRIAL
Since her Cancer Council NSW project grant concluded, Professor Damian’s research on nicotinamide has made incredible progress. Her team won a grant from the National Health and Medical Research Council to undertake a landmark skin cancer prevention clinical trial called ONTRAC (“Oral Nicotinamide To Reduce Actinic Cancer”).
The trial was conducted across the Royal Prince Alfred and Westmead Hospitals and included 386 patients who were randomly assigned to receive either a twice daily dose of nicotinamide or a placebo for one year. All the patients had been diagnosed with at least two non-melanoma skin cancers in the previous 5 years, which meant they were at a high risk of developing more cancers. During the twelve months of study, this group of patients collectively grew 800 new skin cancers.
WHAT DID THE TRIAL DISCOVER?
- The final results of ONTRAC were published in the New England Journal of Medicine and made international headlines.
- The team found that at 12 months, the rate of non-melanoma skin cancers was 23% lower in the nicotinamide group than in the placebo group.
- The number of precancerous lesions was also 13% lower among the people taking nicotinamide compared to those not taking nicotinamide.
WHO CAN USE NICOTINOMIDE (VITAMIN B3) TO PREVENT SKIN CANCERS?
Professor Damian emphasised that using nicotinamide to prevent skin cancer is a high-dose treatment rather than a supplement. “This treatment is only for people with a defined medical condition – multiple skin cancers.”
“It’s not suitable for the general population, as we do not have any evidence that it would be beneficial in a lower risk setting.”
Before taking nicotinamide, people should consult with their GP to see whether nicotinamide is suitable for them. It is also very important that people planning to take vitamin B3 take the amide form, nicotinamide, and not the nicotinic acid form. “Nicotinic acid has a range of unpleasant side effects – including flushing, headache and low blood pressure – that we don’t see with nicotinamide”, says Professor Damian.
HOW DOES VITAMIN B3 WORK?
Ultraviolet (UV) radiation causes skin cancer by damaging the DNA in cells, reducing the amount of energy available to repair damage, and interfering with the immune system in skin cells. DNA provides “instructions” for cells to grow normally. Damaged DNA can result in uncontrolled growth — skin cancer.
Vitamin B3 helps repair UV-damaged cells and reduce the risk of skin cancer by:
- Making more energy available to cells
- Helping repair damaged DNA, and
- Reducing the immune suppression caused by UV radiation1.
In high-risk people who have already had a non-melanoma skin cancer, i.e. a basal cell carcinoma (BCC) or a squamous cell carcinoma (SCC), taking vitamin B3 tablets daily reduces the risk of future non-melanoma skin cancer.
HOW MUCH VITAMIN B3 TO TAKE?
The largest trial of vitamin B treatment2 showed that it is an effective and low-risk treatment. At a dose of 500mg twice daily, taken for a year, the rate of new non-melanoma skin cancers was reduced by approximately 23 per cent:
- Basal cell carcinomas were reduced by 20 per cent. Less serious superficial basal cell carcinomas were prevented more effectively than more aggressive forms of basal cell carcinoma1.
- Squamous cell carcinomas were reduced by 30 per cent. This reduction was the same for superficial and more aggressive squamous cell carcinomas.
Some people get better results than this. In an earlier study3, nicotinamide was found to reduce non-melanoma skin cancer rates by up to 75 per cent, but these figures have not been reproduced across larger numbers of patients.
Vitamin B seems to work best in people with the highest levels of risk, i.e. those who have had many BCCs or SCCs previously2.
Oral nicotinamide is now recognised as an important part of the routine treatment of people at high risk of BCC and SCC and is about to become part of the Cancer Council’s national treatment guidelines for BCC and SCC4.
Protection from vitamin B3 only lasts while it is being taken5. In other words, for long term reduction of non-melanoma skin cancer, it needs to be taken indefinitely.
WHAT FOODS IS VITAMIN B3 PRESENT IN?
Vitamin B3 is present in small amounts in yeast, meat, fish, eggs, milk, nuts, legumes and cereals12. The average daily requirement for vitamin B3 is 15-20mg1. This is easily met by a balanced diet containing the foods mentioned above. But the amount shown to reduce skin cancer risk is about 50 times this amount and can’t be achieved by dietary intake alone.
Vitamin C is a potent antioxidant drug that can be used topically in dermatology to treat and prevent changes associated with photoageing. It can also be used for the treatment of hyperpigmentation. Because it is unstable and difficult to deliver into the dermis in the optimum dosage, research is being directed to find stable compounds of Vitamin C and newer methods of delivery of Vitamin C into the dermis.
The toxic effects of vitamin C on tumor cells may be related to the induction of oxidative stress in cells. However, when the antioxidation system of tumor cells is incomplete, the balance is destroyed, and the oxygen-promoting effect of vitamin C leads to the death of tumor cells (Kim K. et al., 2015; Uetaki et al., 2015). Vitamin C is often used as an adjunct to chemotherapy for tumors. Vitamin C can also increase 5-hydroxymethylcytosine (5hmC) content in melanoma cells and cause a decrease in tumor-cell invasiveness and growth (Gustafson et al., 2015). Thus, vitamin C can be regarded as a potential antitumor drug for the prevention of invasion and metastasis of melanoma, which weakens the tumor capsule integrity and invasiveness and reduces the degree of malignancy.
However, there is still a lack of understanding about the route of administration for vitamin C, the dosage of medication and the complications. We should increase awareness of the fact that high concentrations of vitamin C induce apoptosis of malignant melanoma cells, while low concentrations promote the growth of tumor cells (Yang et al., 2017). H
Vitamin D forms in the skin when it is exposed to UV from sunlight. It can also be obtained from some foods. We need vitamin D to maintain good health and to keep bones and muscles strong and healthy.
The best source of vitamin D is UVB radiation from the sun. UV radiation levels vary depending on location, time of year, time of day, cloud coverage and the environment.
For most people, adequate vitamin D levels are reached through regular incidental exposure to the sun. When the UV Index is 3 or above (such as during summer), most people maintain adequate vitamin D levels just by spending a few minutes outdoors on most days of the week.
In late autumn and winter in some southern parts of Australia, when the UV Index falls below 3, spend time outdoors in the middle of the day with some skin uncovered. Being physically active (e.g. gardening or going for a brisk walk) also helps boost vitamin D levels.
Adequate levels of Vitamin D promote good immunity. Vitamin D can modulate the innate and adaptive immune responses. Deficiency in vitamin D is associated with increased autoimmunity as well as an increased susceptibility to infection. At this point in time however we have insufficient evidence to recomment Vitamin D supplementation as a method to decrease Malignant Melanoma.
Vitamin E is an important fat-soluble antioxidant and has been in use for more than 50 years in dermatology. It is an important ingredient in many cosmetic products. It protects the skin from various deleterious effects due to solar radiation by acting as a free-radical scavenger. Experimental studies suggest that vitamin E has antitumorigenic and photoprotective properties