Antioxidants Role in Health – Part 6: Green Phytonutrients
In Part 5 of this series, we introduced you to the Orange and Yellow Phytonutrients, many of which have been shown to help improve vision and eye health. Many of the foods that contain green phytonutrients also help improve eye health. In addition, the green phytonutrients convey a wide variety of unique health benefits.
Lutein and zeaxanthin are green phytonutrients that have been shown to maintain good vision while reducing the risk of cataracts and macular degeneration. While these two nutrients are widely found in various supplemental formulas, they are also plentiful in foods, including kale, spinach, leafy greens (turnip, collard, and mustard), romaine lettuce, broccoli, green peas, kiwifruit, and honeydew melon.
Cancer Risk Reduction
Another key group of green phytonutrients are the indoles, which includes indole-3-carbinol and diindolylmethane. These compounds are not only potent antioxidants, they have also been shown to convey significant protection against a variety of cancers. In fact, these indoles have been shown to significantly reduce the risk of breast and prostate cancers while reducing the risk of tumor growth in most types of cancer, including melanoma.
Indoles seem to exhibit their cancer-protection by altering estrogen metabolism to produce less-carcinogenic metabolites. It also seems to directly inhibit the growth of reproductive cancer cells. Indoles are readily found in a variety of vegetables, including broccoli, cabbage, brussel sprouts, bok choy, arugula, Swiss chard, turnips, rutabaga, watercress, cauliflower and kale.
Chlorophyll is another potent antioxidant that is found in all green vegetables. Chlorophyll has also been shown to have anti-cancer properties. Research has shown that chlorophyll can bind to potential carcinogens and interfere with how they are absorbed in the human gastrointestinal tract; these studies suggest that these effects help lower the risk for certain types of cancers, including liver and colon cancer.
Another group of antioxidants that have been found to reduce the risk of cancer are the Blue & Purple Phytonutrients; these will be the subject of our next post.
- Hsu, J; Dev, A; Wing, A; Brew, C; Bjeldanes, L; Firestone, G (2006). “Indole-3-carbinol mediated cell cycle arrest of LNCaP human prostate cancer cells requires the induced production of activated p53 tumor suppressor protein”.
- Kima DS, Jeong YM, Moon SI, Kwon SB, Park KC (2011).” Indole-3-carbinol and ultraviolet B induce apoptosis of human melanoma cells via down-regulation of MITF” Pharmazie.Dec;66(12):982-7.
- Kundu A, Quirit JG, Khouri MG, Firestone GL (2017). Inhibition of oncogenic BRAF activity by indole-3-carbinol disrupts microphthalmia-associated transcription factor expression and arrests melanoma cell proliferation. Mol Carcinog.;56(1):49-61.
- Kundu A,Aronchik I,Quirit JG, Firestone GL (2014). The antiproliferative response of indole-3-carbinol in human melanoma cells is triggered by an interaction with NEDD4-1 and disruption of wild-type PTEN degradation. Mol Cancer Res.;12(11):1621-1634.