Quercetin is a supplement from red wine and other fruits that has been studied for decades and found to protect your body against age-related disorders. It particularly is beneficial to improve the health of the inner linings of your arteries, called the endothelium. It may prevent many destructive factors of aging through its anti-inflammatory and antioxidant qualities. Taking quercetin has long been considered a broad-based anti-aging strategy.

Quercetin is a natural compound found in many foods, such as onions, parsley and apples. Remember the old saying, “Eat an apple a day to keep the doctor away.” However, most people don’t ingest enough apples or other foods to provide them with the power of quercetin to improve their heart health. You may need to supplement your nutrition with quercetin. Having adequate levels of quercetin in your blood can improve the health of your heart and blood vessels in many ways.

Endothelium Damage and Cardiovascular Health

Plaques may form under the endothelial lining of the arteries in a known fashion. First a cell lifts slightly, possibly due to the forces of the blood running through it. The more force is presented with this flow, such as with high blood pressure, the more likely damage to the endothelium may occur.

Once slightly lifted, if you have a lot of bad cholesterol, the tiny granules of cholesterol in your blood, these can rapidly accumulate below the endothelial cells and form plaques. These undergo oxidative damage and the development of oxidative damage, called reactive oxidative species (ROS) which damages the endothelial cells.

Your body tries to repair this damage and sends in immune cells. If overwhelmed, inflammation occurs resulting in further damage. This inflammation, when severe, can result in liquefaction of the plaque, rupture, and potentially clotting of the artery. This is not a good thing for the heart and the brain, for a heart attack and/or a stroke can then happen that is life threatening.

Quercetin Improves Arterial Health

Quercetin helps improve endothelial health through several mechanisms. When the endothelium is improved, health of the heart is also improved. Think about when you or someone you know has complaints of chest pain. What do the doctors check? They evaluate the arteries that feed the heart. Thus, improving arterial health correspondingly improves heart health.

Dietary flavanols and flavones such as quercetin have a significantly lower risk for developing vascular diseases for good reasons. Quercetin helps prevent this through many mechanisms. Quercetin is considered a polyphenol and these reduce ROS and inflammation in the body, including the endothelium.

Studies show a regression of atherosclerotic plaque by quercetin through many mechanisms. It triggers transport of cholesterol from the arterial wall by using your good cholesterol HDL. HDL has been shown to improve heart health through its ability to take cholesterol away from the deposits of cholesterol and transport them to the liver for safe disposal. [1],[2] The higher your blood level of HDL, the more likely you can transport these bad deposits away from your endothelial walls before build-up occurs.

However, once inflammation sets in you got trouble. But quercetin may decrease the ROS that forms, including the mitochondrial ROS excess before it can cause excess damage[3] Quercetin also inhibits some of the inflammatory enzymes that cause further damage. These include COX-2, which forms prostaglandins and cause inflammation and pain; MMPs, metalloproteinases that dissolve tissue; and 5-LOX, which forms inflammatory compound such as leukotriene. These are the enzymes that produce the pro-inflammatory molecules that can destroy the tissues of the arteries and form the plaques. [4], [5]

Quercetin also restores normal production of nitric oxide, which is important for relaxation of arterial muscles to allow them to dilate and improve blood flow.[6] This is particularly important in those with high blood pressure. If you can relax your arteries better and they are not so “stiff”, you could reduce hypertension and coronary artery disease.[7] One human study showed that a quercetin-containing food improved after-meal endothelial function by 31.4%.[8]

Improving endothelial health equates to better heart health. The chest pain person we discussed gets an evaluation of their heart vessels through an angiogram, where they use a special x-ray and die to see the vessels of the heart. If plaque have formed and is constricting the arteries that go to the heart, that’s bad. They can stent them or do a bypass surgery, but the best plan is to start in your 40’4 to 50’s and prevent the problem. One method is to boost your quercetin levels.

Heart Protection with Quercetin

Studies have shown that long term ingestion of dietary flavanols and flavones such as quercetin have a significantly lower risk for developing cardiovascular diseases.[9] Quercetin is considered a polyphenol, and these reduce ROS and inflammation in the endothelium. In addition, mitochondrial ROS is also reduced while the number of mitochondria in muscle is increased.

Looking at a human study, men who took 1,000 mg/day of quercetin for just two weeks were able to increase the distances they could run on an increase in mitochondria in the muscle. Mitochondrial numbers grew in the muscles by 4.1% in supplemented group, while falling 6% in the placebo group.[10]

In a mouse study, giving quercetin for just seven days showed a biopsy proven increase in the formation of new mitochondria in the muscles and brains of the mice.[11] Along with this increase was an increase in exercise endurance of the mice taking quercetin versus those not taking it. This finding would correlate with the increase in mitochondria that quercetin induced.

Conclusion

One of the many dietary nutrients that you can take that may improve your heart health is Quercetin. It has many effects that prevent endothelial destruction and formation of plaques, but once these happen, devastating heart disease can take hold. Start boosting quercetin levels in your body early, either with a good diet or supplements to ensure adequate levels. Continue this as a part or your regiment to improve the health of your blood vessels, and in turn this will improve your heart health.

 

These statements have not been evaluated by the Food and Drug Administration (FDA). Any products are not intended to diagnose, treat, cure, or prevent any disease.

References:

[1] Ohara K, Wakabayashi H, Taniguchi Y, Shindo K, Yajima H, Yoshida A. Quercetin-3-O-glucuronide induces ABCA1 expression by LXRalpha activation in murine macrophages. Biochem Biophys Res Commun. 2013 Nov 29;441(4):929-34. doi.org/10.1016/j.bbrc.2013.10.168

[2] Lee SM, Moon J, Cho Y, Chung JH, Shin MJ. Quercetin up-regulates expressions of peroxisome proliferator-activated receptor gamma, liver X receptor alpha, and ATP binding cassette transporter A1 genes and increases cholesterol efflux in human macrophage cell line. Nutr Res. 2013 Feb;33(2):136-43. doi.org/10.1016/j.nutres.2012.11.010

[3] Davis JM, Murphy EA, Carmichael MD, Davis B. Quercetin increases brain and muscle mitochondrial biogenesis and exercise tolerance. Am J Physiol Regul Integr Comp Physiol. 2009 Apr;296(4):R1071-7. doi.org/10.1152/ajpregu.90925.2008

[4] Bhaskar S, Kumar KS, Krishnan K, Antony H. Quercetin alleviates hypercholesterolemic diet induced inflammation during progression and regression of atherosclerosis in rabbits. Nutrition. 2013 Jan;29(1):219-29. doi.org/10.1016/j.nut.2012.01.019

[5] Scoditti E, Calabriso N, Massaro M, et al. Mediterranean diet polyphenols reduce inflammatory angiogenesis through MMP-9 and COX-2 inhibition in human vascular endothelial cells: a potentially protective mechanism in atherosclerotic vascular disease and cancer. Arch Biochem Biophys. 2012 Nov 15;527(2):81-9. doi.org/10.1016/j.abb.2012.05.003

[6] Shen Y, Ward NC, Hodgson JM, et al. Dietary quercetin attenuates oxidant-induced endothelial dysfunction and atherosclerosis in apolipoprotein E knockout mice fed a high-fat diet: A critical role for heme oxygenase-1. Free Radic Biol Med. 2013 Dec;65:908-15. doi.org/10.1016/j.freeradbiomed.2013.08.185

[7] Fitzpatrick DF, Hirschfield SL, Coffey RG. Endothelium-dependent vasorelaxing activity of wine and other grape products. Am J Physiol. 1993;265:H774-8. /doi.org/10.1152/ajpheart.1993.265.2.H774

[8] Nakayama H, Tsuge N, Sawada H, Higashi Y. Chronic intake of onion extract containing quercetin improved postprandial endothelial dysfunction in healthy men. J Am Coll Nutr. 2013;32(3):160-4. doi.org/10.1080/07315724.2013.797858

[9] Scoditti E, Calabriso N, Massaro M, et al. Mediterranean diet polyphenols reduce inflammatory angiogenesis through MMP-9 and COX-2 inhibition in human vascular endothelial cells: a potentially protective mechanism in atherosclerotic vascular disease and cancer. Arch Biochem Biophys. 2012 Nov 15;527(2):81-9. doi.org/10.1016/j.abb.2012.05.003

[10] Nieman DC, Williams AS, Shanely RA, et al. Quercetin’s influence on exercise performance and muscle mitochondrial biogenesis. Med Sci Sports Exerc. 2010 Feb;42(2):338-45.

[11] Davis JM, Murphy EA, Carmichael MD, Davis B. Quercetin increases brain and muscle mitochondrial biogenesis and exercise tolerance. Am J Physiol Regul Integr Comp Physiol. 2009 Apr;296(4):R1071-7. doi.org/10.1152/ajpregu.90925.2008