Nature provides us with thousands of bioactive compounds to help us achieve optimal health, but there is one that truly stands out for its anti-inflammatory activity, and that is a compound known as quercetin.

Quercetin is a naturally occurring flavonoid that is found in a variety of fruits and vegetables including capers, onion, kale, broccoli, asparagus, apples, dark berries, and others. Flavonoids are pigments that provide plants with flavor, color, and fragrance and protect them from free-radical damage, among other functions. The human body cannot produce these phytochemicals so we must get them through diet or supplementation.

The interesting thing is that when we ingest them, they also work as antioxidants and protect us from free-radical damage! Let’s look at some of the other benefits of ingesting quercetin.

Benefits

• Anti-inflammatory Effects. Quercetin has anti-inflammatory effects through a number of different pathways. It can block the production and release of pro-inflammatory molecules like cytokines and chemokines and can also inhibit the enzymes that produce inflammatory compounds like cyclooxygenase (COX) and lipoxygenase (LOX). As an antioxidant, it also scavenges the free radicals and reactive oxygen species that can cause inflammation. It can modulate the signaling pathways involved in the expression of inflammatory genes, thus regulating the inflammatory response. It can also affect the activation and migration of immune cells involved in inflammation. Finally, in cases of inflammation associated with allergy, quercetin can stabilize mast cells, thus reducing the allergic and inflammatory response.
• Heart Health. Quercetin helps enhance the production of nitric oxide, a molecule that acts to dilate blood vessels and reduce blood pressure. This has resulted in improved health of the inner linking of blood vessel walls (the endothelium). Its antioxidant effects can help reduce the buildup of plaque in the arteries. Some studies show that quercetin may reduce levels of LDL (bad) cholesterol. It also may inhibit platelet aggregation, reducing the risk of blood clot formation, and may also have anti-arrhythmic properties, helping to stabilize heart rhythm. Finally, its anti-inflammatory effects may also reduce the risk of cardiovascular disease.
• Immune Support. Quercetin has been shown to enhance the activity of certain immune system cells to help the body respond more effectively to infections and immune challenges. As noted above, it regulates inflammatory responses, modulates cytokine production, and protects against oxidative stress. In addition, quercetin has direct antiviral properties against respiratory viruses.
• Allergy Relief. As noted above, quercetin can stabilize mast cells, decreasing the release of histamine in response to allergenic stimuli. In fact, quercetin has been shown to have antihistaminic effects. Also as mentioned, quercetin can directly decrease the inflammatory response to allergens. Studies have explored the use of quercetin supplementation for allergic conditions and a decrease in nasal congestion, sneezing, and itching were noted.
• Cognitive Health. Research is ongoing to discern the specific ways that quercetin my benefit cognitive health. Its antioxidant properties are thought to decrease oxidative stress in the brain, which is associated with neurodegenerative disorders. It also reduces the chronic inflammation thought to be associated with Alzheimer’s and Parkinson’s Diseases. In addition, there is evidence that quercetin may inhibit the aggregation of amyloid-beta peptides, slowing the formation of amyloid plaques in Alzheimer’s disease.  Through production of nitric oxide, the resulting improved blood flow helps get oxygen and essential nutrients to the brain. Quercetin may also inhibit the death of neurons in the brain, and influence the production of neurotransmitters.
• Exercise performance. The antioxidant and anti-inflammatory effects of quercetin may help to combat the oxidative stress generated by exercise. In addition quercetin might influence mitochondrial function and oxygen utilization, helping to increase energy production and improve endurance. Reduced inflammation may lead to faster recovery of muscle function and less muscle soreness following intense physical activity. Some studies have explored the combined effects of quercetin with other compounds, such as caffeine or omega-3 fatty acids, on exercise performance. Synergistic effects between quercetin and other bioactive compounds may further enhance exercise-related benefits.

Are all Quercetins Alike?

Quercetin can be found in many forms, but they are not all equal. Some are poorly absorbed by the body and others have a very short half-life. Quercetin in its dihydrate form has the best bioavailability, followed by glycosides, aglycone, and rutinoside. While quercetin dihydrate may be insoluble in water, in physiologic or biological salt solutions it is easily available, especially to first-responder phagocytic and dendritic cells.

In addition, there are certain compounds that can further improve absorption and bioavailability of quercetin, such as OPC and vitamin C. OPC, short for oligomeric proanthocyanidins, are a group of antioxidant flavonoids found in grape seeds and pine bark that have been studied for their ability to enhance the bioavailability of other flavonoids, including quercetin:

• OPC can form stable complexes with quercetin that improve water solubility and absorption.
• OPC can protect quercetin from oxidative degradation leading to greater stability of the OPC-quercetin complex.
• OPC may influence the metabolism of quercetin in the body. The interaction between OPC and quercetin may result in a more favorable distribution pattern, potentially enhancing its availability to target tissues.

The interaction between quercetin dihydrate and vitamin C (as buffered ascorbates) involves several mechanisms that contribute to enhanced absorption:

• Buffered ascorbates can prevent the oxidation and degradation of quercetin.
• Buffered ascorbates can create a stable complex with quercetin, improving its solubility in the GI tract and improving absorption.
• Buffered ascorbates may influence transport mechanisms across the GI membrane, also assisting with absorption.
• Buffered ascorbates may inhibit efflux transporters in the gut that would pump out quercetin, potentially increasing the retention of quercetin in the gut for absorption.
• Buffered ascorbates can regenerate quercetin from its metabolites, leading to higher circulating levels in the bloodstream.

Supplementation

If you are considering supplementation with quercetin, ask your healthcare practitioner about PERQUE products. PERQUE uses only low molecular weight quercetin dihydrate sourced from Saphora japonica, combined with the preferable low molecular weight OPC (not regular OPC that can be crushed grape seeds) for more effective absorption in the anti-inflammation products like PERQUE Pain Guard Forté™ and PERQUE Repair Guard™. Take along with PERQUE Potent C Guard™ buffered ascorbates powder to enhance bioavailability even further.

Did you enjoy this post? We post new content regularly! Click here to see our latest blog posts and click here to subscribe to our weekly email newsletter.