Blood vessel function is important for staying healthy. Impaired blood vessel function can lead to an increase in blood pressure (hypertension). If left unchecked, hypertension can lead to heart disease and, ultimately, death. Pretty scary stuff. 

A small increase in the diameter or radius of a blood vessel (called dilation) can lower blood pressure and increase blood flow up to four times as much. In other words, dilation of small blood vessels may have a large impact in how it relates to overall blood pressure.

Many factors affect blood pressure, with the common ones being age, biological sex and lifestyle. One lifestyle factor is the amount of salt we eat. As delicious as a salty French fry or potato chip is, more than 5,000 milligrams per day of salt (about one teaspoon) has been associated with impaired blood vessel function and increases in blood pressure. These findings led the National Institutes of Health to develop a diet centered around reducing sodium intake, called the DASH diet.

Typically, when people think of sodium, they don’t think of cheese, which is pretty high in sodium. For example, a one-ounce serving of Parmesan—and let’s be honest, who eats just one serving?—contains 15% of our recommended dietary allowance of sodium. But the cool thing about cheese is that it contains bioactive proteins, meaning they affect our physiology when we eat them. In animal studies, these proteins have been shown to protect blood vessel function. This led researchers from Penn State to think that cheese may protect the blood vessels in people, too.

To test this theory, the researchers had healthy adults follow two diets: a typical high-sodium diet and a high-sodium diet that also included about 24 ounces of cheese each day. The volunteers followed each diet for one week. The small blood vessels in the skin didn’t dilate as well when the volunteers ate sodium only. Interestingly, after switching diets and “getting cheesy,” the blood vessels’ ability to dilate was preserved even when the volunteers ate the same amount of sodium.

The research team learned that a high-salt diet reduces levels of the blood vessels’ natural vasodilator, nitric oxide. But when cheese is incorporated into the diet, it protects nitric oxide from being damaged or destroyed, so the blood vessels’ ability to dilate is maintained. It’s still not clear whether this protection can be maintained for longer than a week. In the meantime, for the sake of our blood vessels, skip the shaker and hit the grater.