Sinatra's Super Foods: Onions

Although many people may not value the odoriferous qualities of onions, as a cardiologist I certainly value the fibrinolytic qualities of onions—that is, their ability to help promote thinner blood and break up blood clots, which are important factors in staving off heart disease.

What's more, onions also can help normalize blood pressure. When I was researching my book Lower Your Blood Pressure In Eight Weeks (Ballantine Books, 2003), I collected quite a bit of positive data on onions.

As the research on onions reveals, it is most likely the powerful antioxidant quercetin contained within onions that is the key to their heart-healthiness. Quercetin has been shown to significantly reduce high blood pressure in hypertensive patients. In one study, participants took 730 mg of quercetin daily for one month, and the group averaged a solid drop of seven systolic points and five diastolic points.

In another South African study, quercetin was given to salt-sensitive rats with induced hypertension. There was a significant blood pressure-lowering effect, most likely due to improved kidney function. The researchers suggested that quercetin may be worthwhile for people whose blood pressure is influenced by their salt intake.

In addition to lowering blood pressure, quercetin has also been shown to reduce inflammation in the body and block the oxidation of LDL cholesterol, which leads to clogged arteries.

Opt for Onions

For the biggest heart-health benefits, eat onions raw, as they retain their greatest medicinal punch before they are cooked. So slice them up and top off your salads, tuck them into your sandwiches, or just eat them along with other favorite foods. I think raw onions are delicious with sardines.

To work even more onions into your diet, look for new recipes that contain onions. In particular, many Italian, Spanish, French, and Greek dishes use onions liberally. And for super heart-healthy dishes, I always recommend combining onions with other ingredients that can help lower blood pressure, such as garlic and olive oil, as in the following tomato sauce recipe. (Get more heart-healthy recipes.)

Easy Italian-Style Tomato Sauce

• 2 Tbsp. olive oil
• 3 garlic cloves, finely chopped
• 2 medium onions
• 2 cans Italian-style plum tomatoes or 2 lbs. fresh plum or cherry tomatoes
• 2 Tbsp. red or white wine
• 1 Tbsp. chopped basil
• 1 tsp. fresh oregano leaves, crushed
• Sea salt and freshly ground pepper to taste

Pour the olive oil into a pan and saute the garlic and onions for 30 seconds to 1 minute. If you're using canned tomatoes, crush or chop them in a blender. For fresh tomatoes, chop them into small cubes. Add wine and cook for 3 to 4 minutes. Add the basil, oregano, salt, and pepper. The sauce will keep for up to 1 week, tightly covered, in the refrigerator.

Makes 6 servings.

Nutrition facts (per serving): Calories 100, Total Fat 5 g, Sodium 15 mg, Carbs 12 g, Fiber 3 g, Protein 2 g

Get all the details on other Sinatra's Super Foods.

WATCH: Dr. Sinatra's Top 12 Healing Foods

Video courtesy of HeartMDInstitute