If your blood sugar is too high and you’re fighting the battle of the bulge, there’s an easy way to enhance your insulin sensitivity and better regulate your blood sugar.

Drink a long cool glass of beet juice before a meal.

Background: The idea that drinking beet juice has a positive effect on general health is hardly new. Beet juice is rich in dietary nitrate, which the body uses to make nitric oxide, a compound that helps widen blood vessels, improving circulation. Drinking beetroot juice has been shown to reduce blood pressure, improve blood flow to the brain, improve athletic performance and even prevent altitude sickness. Improving circulation also helps the body deliver glucose to the tissues more efficiently so that the body needs to produce less insulin to metabolize food and control blood sugar. But obese people tend to have low nitric oxide levels. Could beets help boost their nitric oxide and improve their insulin sensitivity? To find out, researchers gave people beet juice and a large amount of sugar to digest. It’s a way to simulate the effects of a meal in a lab.

Study: Twelve nonobese men and women and 10 obese men and women took part. Being obese is a significant risk factor for developing diabetes, although none of the participants actually had diabetes. They all were asked to not eat any nitrate-rich foods such as beets or greens the day before. They were also asked to not brush their teeth, floss or use mouthwash for 18 hours before the test. On the day of the study, they each drank a 17-ounce glass of beet juice and then were given a large amount of glucose sugar to consume.

On another day, they rinsed with mouthwash—which prevents the body from turning beet’s nitrates into nitric oxide—before consuming the beet juice and sugar. It may seem odd to study this—after all, who rinses with mouthwash before a meal? But the researchers had a reason. They knew that the healthful bacteria in the mouth are needed to convert beet’s nitrates into nitrites, the first step for the body to make nitric oxide. When you kill the bacteria in your mouth with mouthwash, they aren’t around to do the necessary work.

Result: For the obese beet-juice drinkers, insulin resistance was improved and blood sugar didn’t go up as much in the 60 to 90 minutes after consuming the sugar—compared to when they rinsed with mouthwash first. Their insulin resistance and blood sugar still were slightly higher than in their nonobese counterparts—but it was a big improvement for them. That’s a key benefit, since elevated insulin resistance plus high blood sugar, over time, increase the risk of developing type 2 diabetes. For the obese, who likely started with low nitric oxide levels, drinking beet juice apparently boosted nitric oxide levels high enough to help them better metabolize sugar.

But the beet juice didn’t have the same effect on participants who weren’t obese—their insulin sensitivity and blood sugar response to eating sugar was normal when they drank beet juice and when they negated the benefits of beet juice by rinsing with mouthwash. Why? One probable reason is that their nitric oxide levels were already sufficient to help their bodies metabolize sugar, so boosting it a little extra with beet juice didn’t have any practical effect.

Bottom line: Obese adults at risk of developing insulin resistance may benefit from adding healthful nitrate-rich foods—including a glass of beet juice—to their meals.

What about the sugar naturally contained in beet juice itself? It’s true that there’s a lot of sugar in beets—and even more in beet juice. But evidence suggests that the physiological benefits outweigh the sugar—just make sure you skip less healthy sources of sugar such as soda, candy and other sweets. You can also experiment with other nitrate-rich foods, such as spinach.

Try this nitrate-rich homemade beet/apple/celery/spinach juice at breakfast: The night before, cut up one medium-sized beet into cubes and freeze it. The next morning, put the cubes in your juicer along with one sliced and cored apple, two chopped celery stalks, one-half cup of spinach and the juice of one small lemon. Like your beets at lunch or dinner instead? Nothing beats roasted beets!

Caution: Before consuming beet juice regularly, ask your doctor whether there’s any reason you should avoid or limit foods such as beets, beet juice and spinach. These foods may not be safe for people who are at risk for kidney stones or who are taking certain medications for heart conditions or erectile dysfunction.