Can Taking Quercetin Lower Your Cholesterol and Triglycerides?

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Quercetin has become increasingly popular over recent years. Touted as an antioxidant, quercetin is a type of flavonoid commonly found in plants. You can find quercetin—alone or combined with other vitamins and herbs—as a supplement, and it is commonly found in the nutrition aisle of your pharmacy or in a health foods store.  Quercetin can also be found naturally in health-promoting "superfoods," including:

  • Blueberries
  • Red wine
  • Kale
  • Green tea

Due to its ability to lower inflammation in some studies, quercetin is currently being studied to treat medical conditions such as inflammation of the prostate, certain immune system disorders, and cancer. Quercetin has also shown promise in treating certain cardiovascular conditions, such as high blood pressure, atherosclerosis, and issues with circulation. Can quercetin also help lower cholesterol and triglyceride levels?

Lowering Lipids: Studies Surrounding Quercetin Not Clear

Initial studies conducted in rabbits and rats taking a quercetin supplement revealed that quercetin lowered total cholesterol and triglyceride levels. It also appeared to reduce inflammatory proteins associated with atherosclerosis. This effect appeared to be dose-dependent - that is, the higher the dose given, the more of an effect the quercetin had on cholesterol and triglycerides.

Additionally, quercetin appeared to show more benefit in animals with elevated lipid levels.

In humans, however, there are not many studies examining the effects of quercetin on lipids - and the results we do have from these studies are conflicting. People with a variety of medical conditions - including diabetes, high blood pressure, and heart disease - participated in these studies.

Quercetin was taken as a supplement in doses between 150 mg and 500 mg daily for up to 10 weeks. Some of these studies showed no changes in cholesterol and triglyceride levels in people taking quercetin. Other studies showed a slight reduction in total cholesterol, triglyceride levels, and LDL cholesterol levels, but this decrease did not appear to be significant. In a couple of studies, HDL cholesterol levels also appeared to decrease.

Should You Include Quercetin in Your Lipid-Lowering Regimen?

Despite having positive impacts on other cardiovascular conditions - such as high blood pressure  - quercetin does not appear to have a significant effect on cholesterol and triglyceride levels in most studies. So, if you are looking for a supplement to solely lower your cholesterol and triglyceride levels - quercetin should not be relied on to do this. There are other treatments available that can keep your lipid levels within a healthy range - and your healthcare provider can help you to find more proven ways to improve your heart health.

If you are looking to include quercetin in your diet naturally, there are plenty of foods that contain this nutrient in small amounts, including:

  • Capers
  • Certain herbs and spices - including fennel, coriander, and oregano
  • Different varieties of onions
  • Leafy greens - especially kale, cabbage, and lettuce
  • Various berries - including elderberries, strawberries and cranberries
  • Asparagus

All of these foods are low in saturated fat and are packed with other heart-healthy nutrients, including soluble fiber and phytosterols - both of which have been shown in studies to slightly lower LDL cholesterol.

If you decide to take a quercetin supplement to improve your heart health, you should speak to your healthcare provider first. It is not known whether or not quercetin can worsen certain medical conditions that you have or if it can interfere with other medications that you are taking.

Sources:

Bhaskar S, Kumar KS, Kripa K, et al. Quercetin alleviates hypecholesterolemic diet induced inflammation during progression and regression of atherosclerosis in rabbits. Nutrition 2013; 29: 219-229.

Egert S, Bosy-Westphal A, Seiberl J, et al. Quercetin reduces systolic blood pressure and plasma oxidized low-density lipoprotein concentrations in overweight subjects with a high-cardiovascular disease risk phenotype: a double-blinded, placebo-controlled cross-over study. Br J Nutr 2009; 102: 1065-1074.

Natural Standard. (2014). Quercetin [Monograph]. Retrieved from http://naturalstandard.com/databases/hw/all/patient-quercetin.asp

Talirevic E, Sehovic J. Quercetin in the treatment of dyslipidemia. Med Arch 2012; 66: 87-88.

Zahedi M, Ghiasvand R, Feizi A, et al. Does quercetin improve cardiovascular risk factors and inflammatory biomarkers in women with type 2 diabetes: a double-blind randomized controlled clinical trial. Int J Prev Med 2013; 4: 777-785.

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