Anti-Cancer Effects of Onions and Mushrooms
March 7, 2011
By Joel Fuhrman MD
by Dr. Joel Fuhrman
Conventional wisdom tells us that vegetables are healthful foods that can help to protect us against disease, but scientists are finding that some vegetables provide more dramatic protection than others. Epidemiological studies have suggested that cruciferous vegetables (such as kale, collards and broccoli) are far more protective against cancer than vegetables overall.1,2
New research is now revealing that onions and mushrooms have previously unrecognized but potent anti-cancer effects. We usually think of brightly colored vegetables as the ones having the most health promoting properties. We know that antioxidants are pigments, and deeply colored plant foods like blueberries are extremely rich in these beneficial pigments. Onions and mushrooms may not be so beautifully colored, but they certainly contain plenty of valuable phytochemicals.
The Allium family of vegetables, which includes onions, garlic, leeks and scallions, are known to have beneficial effects on the cardiovascular and immune systems, as well as anti-diabetic and anti-cancer effects.
Epidemiological studies have found that increased consumption of Allium vegetables is associated with lower risk of gastric and prostate cancers. These vegetables contain protective substances called organosulfur compounds, which are released when the vegetables are chopped, crushed or chewed. These compounds prevent the development of cancers by detoxifying carcinogens, halting cancer cell growth and preventing tumors from obtaining a blood supply.3
In addition to the organosulfur compounds, onions also contain high concentrations of flavonoids.
Flavonoids are a class of antioxidant molecules that includes isoflavones, flavonols, catechins and anthocyanins among others. All of these flavonoids have health-promoting properties.4 Red onions contain at least 25 different anthocyanins, and the predominant flavonoid in all onions is quercetin.5 Quercetin slows tumor development, suppresses growth and proliferation and induces cell death in colon cancer cells.6,7,8 In short, flavonoids such as quercetin can contribute to preventing damaged cells from advancing to cancer. Flavonoids also have anti-inflammatory effects that may contribute to cancer prevention.9
Mushrooms have anti-cancer, anti-inflammatory and immune-supporting properties. Mushrooms contain polysaccharides that are thought to inhibit tumor growth and viral infection by stimulating immune cells.10 Compounds in shiitake mushrooms have been shown to trigger programmed cell death in breast cancer cells.11 In case control studies, consuming mushrooms regularly has been associated with decreased risk of breast cancer in both pre- and postmenopausal women. Frequent consumption of mushrooms decreased the risk of breast cancer by up to 60-70%.12,13,14 Similar associations were observed in studies on stomach and colorectal cancers.15
From a culinary standpoint, mushrooms are excellent foods. They add unique flavors and textures to vegetable dishes, and are delicious paired with fresh herbs. Also there is a wide range of mushroom varieties to choose from, each with their own unique and interesting flavors, such as cremini, shiitake, porcini and maitake. Even the more common button mushrooms have been found to inhibit enzymes that contribute to breast and prostate cancer.16 Onions, garlic, scallions and leeks also provide a big burst of flavor to salads, soups and other vegetable dishes. By combining onions and mushrooms with green vegetables and beans,17 you can create delicious, healthful and powerfully protective meals.
Mediterranean Bean and Kale Sauté
- 2 bunches kale, tough stems and center ribs removed, chopped
- ½ cup sun-dried tomatoes, covered with water, and soaked at least one hour, chopped
- 1 medium onion, finely chopped
- 1 cup shiitake or oyster mushrooms, coarsely chopped
- 3 cloves garlic, pressed
- 1 tablespoon no-salt seasoning blend
- 1 cup cooked beans, any type, or canned, no salt added
- 1 ½ tablespoons raisin vinegar (or other sweet vinegar)
- 1 tablespoon Dijon mustard
- red pepper flakes, to taste
- tomato-based pasta sauce, as desired
In a large skillet, sauté kale, tomatoes, onion, mushrooms and garlic in a little water over medium heat for 5 minutes, adding water as needed.
Add seasoning blend and enough water to keep from scorching. Cover and steam for 10 minutes.
Add beans, vinegar, mustard and red pepper flakes. Cook for 3 minutes or until mushrooms are tender and liquid cooks out.
Stir in pasta sauce.
Photo credit: yeah but
Sources for this article can be found here.