Eating Green to Prevent Cancer

Why do people who eat more plants get less cancer? We’ve talked about some phytonutrients that can act as antioxidants to douse free radicals, how some can boost our liver’s own detoxifying enzymes, and some that even boost our DNA repair enzymes, to patch up any damage done. But 22 years ago, the interceptor molecule hypothesis was postulated. Serving as a first line of defense, interceptors bind to mutagens and carcinogens, and thereby block them from coming in contact with our DNA in the first place.

See, many carcinogens, shown here in blue, have a flat ring system narrow enough to slip into the spine of our DNA, causing mutations. But if some interceptor were able to glom onto the carcinogen first, it may no longer fit into our DNA. So the search was on, combing for the existence of carcinogen-binding molecules, and in 2007 we discovered one such amazing molecule was chlorophyll! The most ubiquitous plant pigment in the world, that which makes dark green leafy vegetables dark green.

In subsequent years, the ability of chlorophyll to “totally abolish” DNA damage of human cells exposed to carcinogens was documented in a petri dish. But what we really need to see is does it work in people. But you can’t just give people carcinogens—unless, you pay them enough. “Effects of Chlorophyll on Low-Dose Aflatoxin in Human Volunteers.”

They had people drink a solution of radioactive aflatoxin, the carcinogen that used to be a problem in peanut butter—with or without spinach chlorophyll. Here’s the big spike in their bloodstream of aflatoxin without spinach in their stomach, and this is with. Apparently, the chlorophyll bound to the aflatoxin and prevented its absorption into the bloodstream. “In sum, these studies provide substantial evidence that chlorophylls can strongly inhibit uptake of aflatoxins in the whole animal”—which, in this case, was us.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Kerry Skinner.

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• Pietrzak M, Halicka HD, Wieczorek Z, Wieczorek J, Darzynkiewicz Z. Attenuation of acridine mutagen ICR-191--DNA interactions and DNA damage by the mutagen interceptor chlorophyllin. Biophys Chem. 2008 Jun;135(1-3):69-75.
• Jubert C, Mata J, Bench G, Dashwood R, Pereira C, Tracewell W, Turteltaub K, Williams D, Bailey G. Effects of chlorophyll and chlorophyllin on low-dose aflatoxin B(1) pharmacokinetics in human volunteers. Cancer Prev Res (Phila). 2009 Dec;2(12):1015-22.
• Hartman PE, Shankel DM. Antimutagens and anticarcinogens: a survey of putative interceptor molecules. Environ Mol Mutagen. 1990;15(3):145-82.
• Tan AC, Konczak I, Sze DM, Ramzan I. Molecular pathways for cancer chemoprevention by dietary phytochemicals. Nutr Cancer. 2011;63(4):495-505.
• Mario G. Ferruzzi, Joshua Blakeslee. Digestion, absorption, and cancer preventative activity of dietary chlorophyll derivatives. Nutrition Research. January 2007;27(1):1-12.
• Rohs R, Bloch I, Sklenar H, Shakked Z. Molecular flexibility in ab initio drug docking to DNA: binding-site and binding-mode transitions in all-atom Monte Carlo simulations. Nucleic Acids Res. 2005 Dec 13;33(22):7048-57.
• Osowski A, Pietrzak M, Wieczorek Z, Wieczorek J.J. Natural compounds in the human diet and their ability to bind mutagens prevents DNA-mutagen intercalation. Toxicol Environ Health A. 2010;73(17-18):1141-9.

Images thanks to Gigillo83 and Jynto via Wikimedia Commons

• antioxidants
• cancer
• carcinogens
• chlorophyll
• collard greens
• detoxification
• DNA damage
• greens
• kale
• mustard greens
• peanut butter
• phytonutrients
• plant-based diets
• spinach
• Swiss chard
• vegans
• vegetables
• vegetarians