I’m assuming that you, dear reader, are already familiar with the term “oxidation” as it relates to human health. In a nutshell, certain unstable chemical compounds called “reactive oxidative species” or “free radicals” create damage in our cells day in and day out, with every breath we take and, yes, every move we make. We call this “oxidative stress.” Antioxidants, as the name would imply, help to counteract this damage.
As with many types of stress in our lives, oxidative stress can be beneficial in low amounts but detrimental in high amounts. In low amounts, oxidative stress stimulates our cells to produce their own internal antioxidants to protect themselves and repair damage to their DNA. In high amounts, oxidative stress activates systems inside cells that cause them to kill themselves rather than continue to grow and divide in a damaged or mutated manner. In very high amounts, oxidative stress can overwhelm these repair mechanisms and cellular suicide systems and lead to survival of damaged cells with faulty DNA, that then go on to divide, grow, and form cancerous tumors.
In the effort to prevent cancer, our jobs are to keep our cells supplied with plenty of the building blocks to make these internal antioxidants and to reduce exposure to oxidative stressors, as we’re able. In a world that is chock full of these stressors – chemical pollution, UV light, ionizing radiation, cigarette smoke, inflammation, and excessive calories – it’s also best for us to ingest a high volume of antioxidants through our food. Luckily for us, the foods that are high in antioxidants are also delicious.
You may or may not recognize some of the names in the wide world of antioxidants. Internally produced antioxidants include superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx), which are produced in increasing amounts in response to oxidative stress. Other internally produced antioxidants include alpha lipoic acid, coenzyme Q10, and uric acid, which are produced in a fairly steady amount and aren’t really ramped up by exposure to stressors. Together these compounds help to directly quench free radicals and also stimulate our cells’ protective mechanisms. In addition, flavonoid antioxidants from foods help to do these same jobs.(1) Some of the subclasses of flavonoids you might recognize include anthocyanidins, flavones, and isoflavones. We’ll talk more about the foods you can find those in later.
The big bad granddaddy of all these antioxidants in our bodies is glutathione (GSH). Not only does it act as an antioxidant itself, it replenishes other antioxidants so they can continue to work longer. A multitude of studies on glutathione have shown us that this master antioxidant is very important for prevention of cancer. We know that deficiency of glutathione leads to many types of cancer, including cancers of the mouth, throat, colon, prostate, bladder, and breast.(2)(3) We also know that oral glutathione supplementation of 1000mg daily has been shown to increase the GSH concentration inside cells of the mouth by 260%, demonstrating that oral supplementation is well absorbed and available to the cells that need its protection the most.(4)
While children and adolescents tend to have a plentiful supply of glutathione, our levels decrease with age, with a steep drop in production around age 45. (5) Add to this the activities and environmental exposures in adulthood that use up and deplete glutathione, and you can see why we need to do all we can to improve this situation. Aside from courting the risk of cancer, we have more rapid aging of tissues when glutathione is deficient. Supplementation of just over 100mg of GSH per day for 6 weeks was shown to decrease skin wrinkles and improve skin volume in a 2009 study. (6) Also, hyperpigmentation from sun exposure (“age spots”) was reduced with GSH supplementation of 500mg daily in a study done in Thailand in 2010. (7)
It’s understandable that studies are done using supplements of glutathione, as that makes it easy to measure and control the amount given to test subjects. But as stated before, glutathione is produced in the cells of our bodies and is available in foods also. Optimal intake of glutathione is more than 250 mg per day but most Americans get only 3 – 150 mg, with the average being 35 mg. What foods supply glutathione, you ask? Wonderful, delicious fruits and veggies like asparagus, spinach, garlic, avocado, squash, zucchini, potatoes, melons, grapefruit, strawberries and peaches, as well as meat and seafood. We can also get the building blocks for making our own GSH by consuming food rich in selenium, alpha lipoic acid, riboflavin, and cysteine. Selenium is plentiful in Brazil nuts, meat, and seafood. Alpha lipoic acid is found in yeast (particularly Brewer’s yeast), meat, and organ meats. Riboflavin is abundant in spinach, avocados, and sunflower seeds. Cysteine is high in eggs and garlic.
Some of the foods known to deplete our internal glutathione supply are unfortunately very high in the typical American diet. We also tend to consume these foods when our glutathione levels are at their lowest, first thing in the morning. What are these depleting foods, you ask? Cereal, bread, tea, coffee, and dairy products. Sorry to break that news to you, but it’s better that you know and can start making healthy choices to replenish your glutathione supply each morning and start your day off strong and protected. Happily, eating the right foods isn’t the only good thing you can do for your body to increase your glutathione supply. You can also do yoga and meditation to boost your production of this master cancer fighter – and those are also wonderful ways to start your day. Stress reduction is really key to improving your natural glutathione levels.
Working right alongside glutathione are antioxidants called flavonoids, which are found in similarly delicious and nutritious foods and herbs. I’m sure you already know some of these, like resveratrol from red and black grapes, red wine, Spanish peanuts (with the red skin), blueberries, and mulberries. Epigallocatechin gallate (EGCG) is found in green and white tea, but other flavone antioxidants in this family are in thyme, parsley, celery, apples, berries, grapes, legumes, hot peppers, and cacao. Important isoflavones such as daidzen and genistein come from fermented soybeans and other legumes. Along with genistein, curcumin and melatonin contain antioxidants that play a role in that programmed cell death that stops mutated cells from reproducing. (9) Turmeric (a.k.a. curcumin), cinnamon, and cardamom are other herbs that contain antioxidants which play this same role. As they say, eat the rainbow! Enjoy a diverse array of delicious foods that will help your body stay cancer free.
One final note on getting the antioxidant benefits from foods or supplements that I want to share is that these compounds are activated and made useful to our bodies by the work of probiotic bacteria in our intestines. Without a healthy, robust population of gut bacteria we don’t realize the full power of eating these wonderful antioxidant foods and herbs. That’s just one more reason in the long, long list of reasons to keep those probiotics in your daily regimen. Anybody else hungry from all this talk about the tasty foods that help your body fight cancer? I am! I’m going to go enjoy a nice cup of blackberries with a dollop of homemade yogurt and power my cells up with antioxidants.
By Dr. Lauri Brouwer, ND
- Surh Y-J. Journal Nutr. 2005;135: 2993S–3001S.
- Flagg EW, et al. American Journal of Epidemiology 139(5):453-65, Mar 1994.
- Schwartz, JL, Shklar, G. Nutr Cancer 26:229-36, 1996.
- Ritchie JP. Enhanced glutathione levels in blood and buccal cells by oral glutathione supplementation. Presented at Experimental Biology, April 22, 2013; to be published in Eur J Nutrition, 2014 Apr.
- Sekhar R, S Patel, A Guthikonda et al. AJCN, 2011 Jul;1-7
- Nishiya M. Health Sciences. 25(2), 77-88, 2009.
- N Arjinpathana and P Asawanonda, J Dermatol Treat. 2010;early online:1-6.
- Jones, DP, et al. FASEB J 3:A1250, 1989
- Sanchez-Barcelo EJ, Recent Pat Endocr Metab Immune Drug Discov. 2012;6(2):108