Benefit Heart Health

Onions include antioxidants and chemicals that combat inflammation, lower triglycerides, and lower cholesterol levels, all of which may lessen the risk of heart disease. Their powerful anti-inflammatory qualities may also help lower blood pressure and prevent blood clots. Quercetin is a flavonoid antioxidant found in high concentrations in onions. Because it is an anti-inflammatory, it may help reduce risk factors for heart disease, such as high blood pressure.

A dosage of 162 mg per day of quercetin-rich onion extract significantly decreased systolic blood pressure by 3–6 mmHg compared to a placebo in a trial of 70 overweight persons with high blood pressure. Onions have been demonstrated to lower cholesterol levels. A study of 54 women with polycystic ovary syndrome (PCOS) revealed that eating raw red onions (40–50 grams per day if overweight, 50–60 grams per day if obese) for eight weeks lowered total and "bad" LDL cholesterol compared to a control group. Furthermore, animal studies suggest that eating onions may lower risk factors for heart disease, such as inflammation, excessive triglyceride levels, and blood clot formation.