Quercetin is truly a hidden jewel in foods that promote improvements in cardiovascular health, cancer prevention and in our immune system. That’s just a small part that this amazing nutrient can do.
Quercetin occurs naturally in a variety of brightly colored plant-based foods. This flavonoid compound has antioxidant and anti-inflammatory properties and may help lower the risk of cancer and heart disease while decreasing blood pressure.
According to the U.S. Department of Agriculture, capers contain one of the highest natural concentrations of quercetin. Canned capers, which are the salt-brined flower buds of the Capparis spinosa plant, contain 173 milligrams of quercetin in every 3.5 ounces, or 14.8 milligrams in a typical 1-tablespoon serving. Use capers in salads, dips, pasta dishes and as a flavor-enhancing addition to sauces for seafood or poultry. Capers are high in sodium. To decrease their sodium content and control the saltiness they add to foods, rinse them thoroughly before using.1
All types of onions are high in quercetin. Raw red onions contain 33.4 milligrams of the compound in every 3.5 ounces, while raw white onions supply 21.4 milligrams, scallions have 18.3 milligrams and fresh sweet onions contain 14.8 milligrams. Cooked onions have 24.4 milligrams of the compound in each 3.5-ounce serving. To get the most quercetin out of your onions, use them promptly after purchase. Onions can lose more than 25 percent of their quercetin content if they're stored over a week.2
Fruits with a dark red or blue hue have the highest quercetin content. These include cranberries, which contain 15 milligrams in every 3.5 ounces; raw black plums, with 12.5 milligrams per serving; and blueberries, which have 5 milligrams. Chokeberries, black currants, apples and cherries are also good sources of quercetin. A 2002 article published in "Nutrition" reported that foods prepared by boiling lost a significant amount of quercetin due to contact with heat and water. Whenever possible, eat quercetin-rich fruits raw or only lightly cooked.3
First, let’s talk about its absorption. Like Turmeric, it must be combined to a carrier nutrient, in this case, Quercetin is best combined with the pineapple enzyme bromelain for maximum effectiveness.
Here are few facts as to why we need Quercetin everyday:
- Quercetin is a one of the pigment molecules responsible for the bright colors in fruits and vegetables.
- Studies suggest that quercetin’s anti-inflammatory and antihistamine properties could reduce asthma attacks triggered by allergies just like it helps relive nasal allergies.
- Quercetin may reduce histamine release in people with seasonal allergies by 96% according to one study.
- Quercetin’s antihistamine properties may help you avoid a scar.
- Studies show that it blocks insulin-like growth factor (IGF), a protein known to promote the excess collagen produced in keloids.
- Quercetin is excellent for allergies due to its natural antihistamine action.
- Quercetin is excellent to reduce prostate gland pain caused by infections and maybe used for prostate enlargement discomfort.
Quercetin is a flavonol type of flavonoid, one of the most prevalent polyphenols in the vegetables and fruits we eat, including the beverages derived from them (like wine and juices). In addition to the antioxidant, anti-inflammatory, and immune-boosting benefits studies have shown quercetin offers, research suggests it may act to prevent the development of new cancer and therapeutically arrest and even regress existing cancer growth.
- Quercetin triggers apoptosis. Apoptosis is a controlled self-destruction where the cell breaks itself down into easily absorbed debris. We must remember healthy cells have a life cycle. They are born and at a given time they will die and be replaced by a new cell. Cancer cells generally do not have a life cycle of sorts. They are born, but they don’t die on their own leaving them to grow uncontrollably until the host dies or an agent is brought to destroy them before they destroy the actual host (the body in this case).4
- Quercetin can act as a natural chemopreventive agent. Studies suggest that quercetin can inhibit the occurrence of new, primary cancers, and halt the progress of existing tumor growth. One of the ways it does this is by blocking angiogenesis, the action in which a cancer cell creates new blood vessels that tumors need to feed new growth.
- Did you know radiation therapy can actually cause angiogenesis? This action can be blocked when radiotherapy is administered with polyphenols that inhibit the growth of new blood vessels. Polyphenols represent non-toxic alternatives to synthetic anti-angiogenesis drugs, and may be more effective because they act on multiple (rather than specific) proteins—blocking the tumor cells from producing more proteins in an effort to survive and use other pathways to grow. This multiple-protein effect by polyphenols helps to avoid the risk of drug resistance that often develops in cancer cells.
- Quercetin has also shown anti-metastasis action. By blocking cancer cells from degrading and penetrating the membrane barrier that separates living cells from the nonliving, structural extracellular matrix in the body, quercetin has been shown to prevent certain cancers from infiltrating the blood stream and spreading into the surrounding and distant tissue.5
1-3. Foods With the Highest Content of Quercetin. Michelle Kerns
4. Goodsell, David S. Molecule of the Month: Caspases. RCSB: Protein Data Bank (PDB); Rutgers University & University of California, San Diego. [Online] August 2004. http://www.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb56_1.html.
5. Sagar, S.M., Yance, M.H. and Wong, R.K. Current Oncology: Natural health products that inhibit angiogenesis: a potential source for investigational new agents to treat cancer—Part 1. PubMed: U.S. National Library of Medicine and the National Institutes of Health. [Online] February 2006. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1891166/.
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