Researchers believe the effect is due to the antioxidants in cheese and that all dairy products may also be good for heart health.
The team from Pennsylvania State University found that when adults consume food high in sodium, they also experience blood vessel dysfunction. But in a randomized, crossover study, when the same adults consumed four servings of cheese daily along with the same high-sodium diet, they did not experience this effect.
Study author Dr. Billy Alba said, "Although there is a great drive to reduce sodium in the diet, many people find this difficult. It's likely that including more dairy products, such as cheese, could be an alternative strategy to reduce cardiovascular risk and improve vascular health without necessarily reducing total sodium."
The researchers recruited 11 adults without salt-sensitive blood pressure for the study. They each followed four separate diets for 8 days: a low-sodium, dairy-free diet; a low-sodium, high-dairy diet; a high-sodium, dairy-free diet; and a high-sodium, high-dairy diet.
In the low-sodium diets, participants consumed 1500 mg of salt per day, while the high-sodium diets included 5500 mg of salt per day. The cheese diets included 170 grams, or about four servings of several different types of cheese per day.
At the end of each one-week diet, they were returned to the lab for testing. Researchers inserted tiny fibers under the participants' skin and administered a small amount of the drug acetylcholine, a compound that signals blood vessels to relax. By studying how each participant's blood vessels responded to the drug, the researchers were able to measure blood vessel function.
Participants also had their blood pressure monitored and provided a urine sample to make sure they consumed the correct amount of salt during the week. The researchers found that after a week on a high-sodium, cheese-free diet, the participants' blood vessels did not respond as well to acetylcholine and had a harder time relaxing.
However, this was not seen after the high-sodium and cheese diet. Lacey Alexander, a professor of kinesiology at Penn and another researcher in the study published in the Journal of Nutrition, says, "While participants were on a high-sodium, cheese-free diet, we saw their blood vessel function decline to the level typically seen in people with fairly advanced cardiovascular risk factors. But when they consumed the same amount of salt and ate cheese as the source of that salt, these effects were completely avoided. Studies have shown that people who consume the recommended number of servings of dairy each day tend to have lower blood pressure and better cardiovascular health overall.
"We wanted to take a closer look at these relationships, and also explore some of the exact mechanisms by which cheese, a dairy product, may affect heart health," she added.
Dr. Alba said that while the researchers cannot be certain that the effects are due to any particular nutrient in the cheese, the data suggest that antioxidants in the cheese may be a contributing factor.
"That's one of the main reasons these substances appear: Consuming large amounts of sodium leads to an increase in molecules that are harmful to blood vessel health and overall heart health. There is scientific evidence that milk-based nutrients, particularly peptides formed during the digestion of milk proteins, have beneficial antioxidant properties, meaning that they have the ability to remove these oxidant molecules and thus protect against their harmful physiological effects," she said. | BGNES
