Scientists from the Hospital of Southern Medical University have found that quercetin — a plant pigment that gives many fruits and vegetables their vibrant colors — may help lower blood pressure.
Quercetin is a type of flavonoid found in a variety of plant-based foods, including capers, red onions, kale, apples, berries, and grapes.
It has a slightly bitter taste and is also used in dietary supplements, beverages, and certain foods.
Previous research suggests quercetin has antioxidant and anti-inflammatory properties that may help reduce swelling, kill cancer cells, control blood sugar, and protect against heart disease. However, clinical studies on its heart-protective effects have produced mixed results.
In the new research, published in Nutrition Reviews, scientists reviewed 17 clinical trials involving 896 participants to assess the impact of quercetin supplementation on cholesterol, blood pressure, and blood sugar.
The results showed that quercetin intake significantly reduced both:
-
Systolic blood pressure — the pressure in arteries when the heart beats.
-
Diastolic blood pressure — the pressure in arteries when the heart rests between beats.
However, cholesterol and blood sugar levels showed no strong overall changes.
When participants consumed quercetin for 8 weeks or longer, researchers noted improvements in:
-
HDL (“good”) cholesterol — helps carry cholesterol to the liver for removal, reducing heart disease and stroke risk.
-
Triglycerides — a type of fat in the blood; high levels can lead to hardened arteries, raising the risk of heart attack and stroke.
The study included a mix of participants — some healthy, others with conditions like type 2 diabetes, obesity, or high blood pressure — making it harder to determine exactly how quercetin benefits each group. Additionally, the trials varied in design, target populations, and participant characteristics, which could influence results.
The findings suggest that quercetin supplementation may be an effective way to lower blood pressure and, over time, improve certain cholesterol and blood fat levels.
More targeted research is needed to confirm its benefits in different populations.
Study conducted by Haohai Huang et al., published in Nutrition Reviews.
