Remember the old saying about an apple a day keeping the doctor away? You probably thought it was true but never knew why. Now researchers have found that the mighty power of the little red fruit comes from its high levels of a special flavonoid called quercetin. This powerful compound has astonishing potential to promote health and prevent disease across the board. But maybe best of all, quercetin is a master at weight loss.
Quercetin halts fat cell accumulation and makes fat cells die
The rising rates of obesity have scientists scurrying to find ways to control the fat cell life cycle. This is quite a task, because fat is complex. Julius Goepp, MD describes it:
“Fat, long considered to be an inert, biologically uninteresting tissue, is now known to be a virtual beehive of metabolic and endocrine activity, producing myriad hormones, inflammatory cytokines, and other molecules that influence health for better or for worse. Fat tisssue mass is essentially the product of new fat cells, their accumulation of fat triglycerides, and their programmed death by the process of apoptosis. Each of these processes can be affected by various natural dietary components.”
Quercetin is exciting these scientists because it is showing evidence of being able to control all these facets of fat!
A newly released study was aimed at identifying compounds that would inhibit the absorption of dietary fats. 37 traditional Chinese herbal medicines were tested for their activity. Coexistent plant chemicals (known as phytochemicals) present in high levels in the three most promising herbs were tested for their anti-lipase activity. Quercetin showed better activity (27.4%) than all the other phytochemicals tested, at a final concentration of 25mg/ml.
Other research has shown that quercetin inhibits fat accumulation in maturing human fat cells in culture while also suppressing the maturation of new fat cells, and at the same time, triggering the death of existing fat cells. Quercetin slows the uptake of glucose from the blood, depriving fat cells of the raw material needed to make and store fat molecules.
Researchers at the University of Georgia found that they could block the production of fat cells and speed their death by using quercetin or resveratrol, another high activity flavonoid. When they used the two together, they decreased fat accumulation by nearly 70%, while increasing the death of fat cells by a whopping 310%.
Other research has shown that quercetin produces a transient increase in energy expenditure. Quercetin supplementation was associated with reduced body weight in obese, insulin-resistant mice.
What else can quercetin do?
Inflammation and accompanying tissue damage are involved in virtually all chronic human diseases and many acute diseases. Researchers in Korea documented that quercetin inhibits the production of inflammation by blocking the effects of NF-kappaB, a major proponent of chronic inflammation. This ability is partly due to the ability of quercetin to inhibit enzymes that promote inflammation.
As an antioxidant, quercetin scavengers free radicals and inhibits damage to fats that safeguard the cells of the nervous system. This is especially true when an injury has occurred. After an initial tissue injury, a chain reaction generates free radicals resulting in further cell damage and death. In this reaction, the hemorrhaging that typically follows injury causes hemoglobin within red blood cells to disintegrate and release oxidized iron, which then triggers the degradation of the lipids in neuronal membranes. Quercetin binds to released iron and prevents it from reacting with the lipids on neighboring cells. This process inhibits swelling that results from tissue damage.
Researchers have shown that quercetin provides significant help in recovering motor function after a spinal cord compression injury. For this study, doses of quercetin were injected into the body cavity of experimental rats who received spinal cord injury, while doses of saline solution were similarly injected into spinal cord injured control rats. Although none of the control rats walked, two-thirds of the quercetin-treated animals recovered some ability to do so.
The same research team has also shown that quercetin reduces oxidative stress-related inflammatory processes following spinal cord trauma, thereby decreasing the extent of secondary injury.
Other research has shown that quercetin fights viral infections and protects against chronic lung disease. It also protects against Alzheimer’s disease, allergies, asthma, heart disease, hypertension, interstitial cystitis, prostatitis, rheumatoid arthritis, and cancer.
Apples are the number one source of quercetin, but it is found in many fruits and vegetables, particularly red grapes, citrus fruits, pears, berries, onions, garlic, parsley, spinach, cruciferous vegetables like broccoli and cabbage, tea, and buckwheat.
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