May 2 (UPI) -- Walnuts may be the key to finding better cardiovascular health, new findings show.
People who switched out 5 percent of saturated fat in their diets for walnuts had lower central diastolic blood pressure readings than those who didn't make the change, according to a study published in the May issue of the Journal of the American Heart Association.
"When participants ate whole walnuts, they saw greater benefits than when they consumed a diet with a similar fatty acid profile as walnuts without eating the nut itself," Penny Kris-Etherton, distinguished professor of nutrition at Penn State University and study author, said in a news release. "So it seems like there's a little something extra in walnuts that are beneficial -- maybe their bioactive compounds, maybe the fiber, maybe something else -- that you don't get in the fatty acids alone."
The researchers suspected that a plant-based omega-3 called alpha-linolenic acid may be the reason walnuts lower blood pressure.
For the study, they enlisted 45 people between ages 30 and 65, who were overweight or obese.
Roughly 12 percent of calories in the average American meal come from saturated fat, so the researchers decided to remove some of that fat and replace it with healthier vegetable oils.
They gave participants meals that substituted a 5 percent reduction in saturated fat with either alpha-linolenic and polyunsaturated acids, oleic acids or whole walnuts.
While each saturated fat substitution improved cardiovascular health, the participants who ate the walnut-substituted meals had lower blood pressure numbers.
Roughly, one in three adults in the United States has high blood pressure, according to the Centers for Disease Control and Prevention.
"Instead of reaching for fatty red meat or full-fat dairy products for a snack, consider having some skim milk and walnuts," Kris-Etherton said. "I think it boils down to how we can get the most out of the food we're eating, specifically, 'how to get a little more bang out of your food buck.' In that respect, walnuts are a good substitute for saturated fat."