Don’t you wish life was simple? If you’re one of those “I crave chaos” people, stop reading and exit my site. If you’re like me and appreciate the rare instance when order trumps disorder, and black-and-white proves to be the case more than grey, then you’ll appreciate my latest conundrum. Antioxidants.
As a dermatologist, not a day goes by when a new beauty product or cosmeceutical is boasting the wide-ranging effects of antioxidants. I am constantly hearing about the touted benefits of these nifty little chemicals purported to scavenge free radicals, clean the body, and prevent all sorts of bad things from happening, including cancer. To get to the root of said conundrum, let’s consider a bit of background.
The concept that antioxidants can help fight cancer is deeply rooted in the general population, promoted by the health and food supplement industry, and supported by some scientific studies. However, large clinical trials have reported inconsistent results when it comes to the benefits of antioxidants for cancer prevention.
Background: Anti-oxidants are so named because they inhibit the oxidation of other molecules. Oxidation is “bad” because it leads to formation of free radicals, or molecules that have 1 unpaired electron. Essentially, having a lone electron makes them highly reactive, setting off numerous chemical reactions, some damaging, inside the cell.
Oxidative damage in DNA can cause cancer. To balance the oxidative stress, our body complex system of internal antioxidants, such as glutathione and enzymes catalase and superoxide dismutase. In addition, there are exogenous antioxidants like vitamin A, vitamin C and vitamin E.
Problem: Recently, two interesting and very important scientific studies questioned the role of antioxidants in cancer progression.
Study #1: a Swedish study published in the prestigious journal, Science and Translational Medicine, in 2014. Researchers found that adding the antioxidants N-acetylcysteine (NAC) or vitamin E to the diets of mice with small lung tumors substantially increased the number, size, and stage of the tumors. So basically, antioxidants encouraged the cancers to grow. This suggests that the oxidative stress from free radicals might actually be beneficial and have an anti-cancer benefit. So much for turning the truth on its head.
Study #2: The same researchers published another important study, again in Science and Translational Medicine, in 2014, this time looking at melanoma. Of course this was of great interest to me since I am a dermatologist. In this study, they found that NAC increased lymph node metastases in an endogenous mouse model of malignant melanoma but has no impact on the number and size of primary tumors. Similarly, NAC and vitamin E increased the metastatic potential of malignant melanoma cells. In a nutshell, mice with melanoma who received these antioxidants had higher rates of melanoma spread to other distant body sites. Not good.
According to the National Cancer Institute website, “The new findings…. suggest that cancer patients and people with an increased risk of cancer should avoid taking antioxidant supplements.”
Take-away: Would I recommend antioxidants as part of a cancer prevention regimen? No. But, the fact is that when it comes to skin health, there is significant data that certain antioxidants, particularly vitamin C, impart myriad benefits to the skin un-related to cancer prevention (e.g. promoting collagen, helping to reduce brown spots, and so on). The cosmetic and anti-aging benefits are clear and indisputable. So while topical vitamin C remains a great component of a skin care regimen, the jury’s out on its role in preventing cancer. (For more on another really interesting vitamin story, that of vitamin B3, or niacinamide, stay tuned for my next post….)