Introduction
As pet owners, we want to make sure our furry friends live happy, healthy lives. Regretfully, dogs can have allergies and other ailments that may call for treatment, just like people. One common way to treat dog allergies is with natural antihistamine for dogs.
Quercetin and Bromelain for Dogs
Quercetin is found in fruits and vegetables such as apples, berries and leafy greens and has anti-inflammatory, antioxidant and antihistamine properties and can be taken orally.
Yellow Chamomile contains compounds that reduce inflammation, soothe skin irritation and relieve itching and can be made into a tea and applied to the skin or consult your veterinarian before taking internally.
Coconut oil has anti-inflammatory and antibacterial properties and can be applied directly to the skin or added to food to relieve dry, itchy and red skin.
The Omega-3 fatty acids in fish oil reduce inflammation caused by allergic reactions, improve skin health, and boost the immune system; fish oil supplements for dogs in liquid or capsule form can be added to the daily diet.
Bromelain and papain, found in pineapple and papaya, enhance the absorption of quercetin and have anti-inflammatory properties, and can be combined with quercetin for enhanced results.
Quercetin for Dogs with Allergies
Quercetin is an antioxidant flavonol that occurs naturally in a variety of foods such as apples, plums, red grapes, green tea, elderflowers, and onions, to name just a few. According to a 2019 Market Watch report, the market for quercetin is growing rapidly as the health benefits of quercetin become better known.
Studies have found that quercetin acts against inflammation and acts as a natural antihistamine. In fact, quercetin's antiviral abilities seem to be the focus of much research, with a large number of studies emphasizing quercetin's ability to prevent and treat the common cold and flu.
However, there are other lesser-known benefits and uses for this supplement, including the prevention and treatment of the following diseases.
| Health Condition | Benefits of Quercetin |
|---|---|
| Hypertension | Helps lower blood pressure and improve vascular function through its antioxidant and anti-inflammatory properties. |
| Cardiovascular Disease | Reduces oxidative stress and inflammation, improves endothelial function, and lowers the risk of atherosclerosis. |
| Metabolic Syndrome | Improves insulin sensitivity, lowers blood glucose levels, and reduces fat accumulation. |
| Certain types of Cancer | Inhibits cancer cell growth and spread through its antioxidant and anti-inflammatory effects. |
| Non-alcoholic Fatty Liver Disease (NAFLD) | Reduces liver inflammation and fat accumulation, improving liver function. |
| Gout | Reduces inflammation caused by uric acid crystals through its anti-inflammatory properties. |
| Arthritis | Decreases joint inflammation and pain, improving joint mobility. |
| Mood Disorders | Improves brain function and alleviates symptoms of depression and anxiety through its antioxidant and anti-inflammatory properties. |
| Lifespan Extension | Delays the aging process and extends healthy lifespan by its senolytic benefits (clearing damaged and aged cells). |
Quercetin Improves Metabolic Syndrome Characteristics
Among the latest papers on this powerful antioxidant is a review published in March 2019 in Phytotherapy Research that reviews nine randomized controlled trials on the effects of quercetin on metabolic syndrome.
Metabolic syndrome refers to a range of health problems that increase the risk of type II diabetes, heart disease, and stroke, including high blood pressure, high blood sugar, high triglyceride levels, and accumulation of fat around the waist.
While comprehensive studies have found no effect of quercetin on fasting blood glucose, insulin tolerance, or hemoglobin A1c levels, further subgroup analyses have shown that supplementation with quercetin “significantly lowered” fasting blood glucose in studies taking at least 500 milligrams per day for at least eight weeks.
Quercetin Helps Regulate Gene Expression
According to a study published in 2016, quercetin also activates mitochondrial channels of apoptosis (the programmed cell death of damaged cells) by interacting with DNA, thereby causing tumors to subside.
Quercetin was found to induce cytotoxicity in leukemia cells, and the effect was dose-related. Additionally, breast cancer cells showed little cytotoxic effects. Overall, quercetin increased the lifespan of mice with cancer by five times compared to untreated controls.
The authors attributed these effects to quercetin's direct interaction with DNA and its quercetin's activation of the mitochondrial pathway of apoptosis, and suggested that the potential use of quercetin as an adjuvant drug in cancer therapy deserves further exploration.
Recent research published in the journal Molecules similarly emphasizes the epigenetic effects of quercetin and its ability to
- Interact with cell signaling channels
- Regulate gene expression
- Influence the activity of transcription factors
- Regulating microRNAs
Once thought to be junk DNA, microRNA has been found to be far from useless, but is in fact a small molecule of RNA that is critical for regulating genes that make proteins in the body.
Tiny ribonucleic acids act as on/off switches for these genes. Depending on the input of the microRNA, a gene can encode any one of over 200 protein products. Quercetin's ability to modulate the number of tiny RNAs may also explain its cytotoxic effects and why it appears to improve cancer survival (at least in mice).
Quercetin Is A Powerful Antiviral Component
As mentioned above, research conducted around quercetin has focused on its antiviral capabilities, which are attributed to three main mechanisms of action:
- Inhibiting the ability of viruses to infect cells
- Inhibiting the replication of already infected cells
- Reducing the resistance of infected cells to antiviral drug treatment
For example, a U.S. Department of Defense-funded study published in 2007 found that after experiencing extreme physical stress, quercetin may reduce your risk of contracting a virus and improve your mental performance, which might otherwise disrupt your immune function and make you more susceptible to disease.
In this study, cyclists received 1,000 milligrams of quercetin a day for five weeks, along with vitamin C (to increase plasma quercetin levels) and niacin (to boost absorption), and found that those taking quercetin were significantly less likely to contract viral illnesses after cycling three hours a day for three days, compared to cyclists who did not receive any treatment. Forty-five percent of those in the placebo group became ill, compared to only 5 percent of those in the treatment group.
The U.S. Defense Advanced Research Projects Agency (DARPA) funded another study, published in 2008, that challenged quercetin-treated animals with the highly pathogenic H1N1 influenza virus. The results were the same, with significantly lower morbidity and mortality in the treated group than in the placebo group. Several other studies have confirmed the effectiveness of quercetin against a variety of viruses, including:
| Year | Research Findings |
|---|---|
| 1985 | Quercetin was found to inhibit the infection and replication of Herpes Simplex Virus Type 1, Poliovirus Type 1, Parainfluenza Virus Type 3, and Respiratory Syncytial Virus. |
| 2010 | Animal studies showed that quercetin could inhibit both Influenza A and B viruses. Additionally, two significant findings were noted: (1) the viruses could not develop resistance to quercetin, and (2) when combined with antiviral drugs (e.g., amantadine or oseltamivir), its effectiveness was significantly enhanced, preventing the development of drug resistance. |
| 2004 | An animal study using an H3N2 virus investigated the effects of quercetin on influenza. The authors noted that oxidative stress occurs during influenza infection and suggested that quercetin might protect the lungs from the harmful effects of reactive oxygen species released during infection by restoring the concentrations of various antioxidants. |
| 2016 | Research found that quercetin could modulate protein expression, providing protection against Influenza A H1N1 virus. Specifically, the regulation of heat-shock proteins, fibronectin 1, and inhibitory proteins helped reduce viral replication. |
| 2016 | Another study found that quercetin inhibited multiple influenza strains, including H1N1, H3N2, and H5N1. The authors concluded that quercetin exhibited inhibitory activity early in influenza infection, suggesting a potential future therapeutic approach through the development of effective, safe, and inexpensive natural drugs for treating and preventing Influenza A virus infections. |
| 2014 | Researchers noted that quercetin seemed promising in treating rhinovirus-induced common colds. Studies confirmed that quercetin reduced viral internalization and replication in vitro and decreased viral load, pneumonia, and airway hyperreactivity in vivo. Additionally, quercetin reduced oxidative damage, lowering the risk of secondary bacterial infections, which are a major cause of influenza-related deaths. Importantly, quercetin increased mitochondrial biogenesis in skeletal muscle, indicating that part of its antiviral effect might be due to enhanced mitochondrial antiviral signaling. |
| 2016 | An animal study found that quercetin inhibited infection by Dengue and Hepatitis viruses in mice. Other studies have also confirmed quercetin's ability to inhibit Hepatitis B and C infections. |
| 2020 | A study published in Microbial Pathogenesis in March 2020 found that quercetin provided comprehensive protection against Streptococcus pneumoniae infection both in vitro and in vivo. It primarily worked by neutralizing a toxin (PLY) released by pneumococcus, preventing the outbreak of pneumococcal infection. The report noted that quercetin significantly reduced PLY-induced hemolytic activity and cytotoxicity by inhibiting oligomer formation. Additionally, quercetin treatment reduced PLY-mediated cell damage, increased survival rates in mice infected with lethal doses of pneumococcus, alleviated lung tissue pathology, and inhibited the release of cytokines (IL-1β and TNF-α) in bronchoalveolar lavage fluid. Considering the importance of these events in the pathogenesis of drug-resistant pneumococcus, the results suggest that quercetin could be a potential candidate for treating clinical pneumococcal infections. |
Quercetin Fights Inflammation and Boosts Immunity
In addition to its antiviral activity, quercetin is also known to boost immunity and fight inflammation, and a 2016 study published in the journal Nutrients suggests that some of the mechanisms of action include, but are not limited to, inhibition of the production of tumor necrosis factor alpha (TNF-alpha) by lipopolysaccharide (LPS) induced macrophages:
Lipopolysaccharide (LPS)-induced production of tumor necrosis factor-alpha (TNF-alpha) in macrophages, a cytokine involved in the systemic inflammatory response that is secreted by activated macrophages, which are immune cells that can phagocytose foreign substances, microbes, and other harmful or damaged elements:
Lipopolysaccharide-induced mRNA levels of TNF-α and interleukin (Il)-1α in glial cells, which leads to reduced neuronal apoptosis.
- Inhibits the production of enzymes that induce inflammation
- Blocking calcium influx into cells
- Pro-inflammatory cytokine release
- Release of histamine and serotonin from intestinal mast cells
According to this article, quercetin also stabilizes mast cells, has cytoprotective activity in the gastrointestinal tract, and has a direct modulatory effect on the basic functional properties of immune cells, which can lead to the inhibition of a large number of molecular targets by down-regulating or inhibiting a wide range of inflammatory channels and functions in the micromolar concentration range.
Quercetin May Be a Useful Supplement for Many Dogs
Considering the wide range of benefits that quercetin has to offer, it may be a useful supplement for many dogs with both acute and more long-term problems. It's also a supplement that I recommend owners always keep in their medicine cabinet, where it can come in handy when they feel like their dog is about to be overwhelmed by a particular health issue, whether it's the common cold or the flu.
If your dog is prone to colds and flu, consider boosting your dog's immune system by taking quercetin a few months in advance of cold and flu season. It also seems to be very useful in the long run for people with metabolic syndrome, but it's foolish to rely solely on one supplement while failing to address basic issues like diet and exercise at the same time.
Quercetin's Multiple Beneficial Help for Dogs
Quercetin is a naturally occurring flavonoid found in many fruits, vegetables and teas. As an antioxidant, quercetin has a significant role in protecting cells from oxidative stress and inflammatory damage. Quercetin has some unique advantages over other antioxidants, especially in supporting lung health and overall immune defense:
Not only does quercetin have potent antioxidant properties, but it also possesses anti-inflammatory, antiviral and antibacterial properties. This makes it particularly unique in its defense against multiple health threats. In contrast, many other antioxidants (e.g., vitamin C and vitamin E) provide primarily antioxidant functions and lack multiple biological activities.
Quercetin effectively inhibits the release of inflammatory mediators such as histamine and leukotrienes, which play a key role in asthma, allergies and other inflammatory diseases. Quercetin is therefore uniquely suited to relieve inflammation-related symptoms and support respiratory health.
Quercetin is able to boost the immune system's defenses by regulating the function of immune cells, such as macrophages and T-cells. This makes it more than just an antioxidant; it can also help defend against pathogens, such as bacteria and viruses, and is especially notable for its role in respiratory health.
Quercetin is able to enter the cell and directly neutralize free radicals within the cell, protecting the cell membrane and DNA from oxidative damage. This deep cellular protection gives it a unique advantage in preventing cellular aging and damage.
Quercetin has a positive effect on vascular function by helping to relax vascular smooth muscle and improve circulation. This also shows significant benefits in maintaining cardiovascular health and promoting overall wellness.
Quercetin can enhance the effects of certain medications while reducing their side effects. For example, it enhances the efficacy of antiviral drugs and reduces damage to normal cells caused by chemotherapy drugs.
