Eating mixed nuts can improve cardiovascular health and your mood

a variety of nuts

A recent study by researchers at the UCLA Center for Human Nutrition found that consuming mixed nuts offers a host of benefits that range from improved cardiovascular health to weight management and brighter mood.

Zhaoping Li, MD, chief of the Division of Clinical Nutrition at UCLA and the principal investigator of the study, said the evaluation began strictly as a weight-management study, but it was expanded when she and her colleagues decided to collect additional data.

“We were trying to address the question of whether or not a snack such as mixed nuts would cause someone to gain weight due to the increased calories and high-fat content,” Dr. Li said. “Instead, we found that eating mixed nuts during caloric restriction actually decreases cardiovascular risk factors and increases satiety.”

Research and findings

For the study, 89 individuals were monitored over the course of two 12-week periods. For the first phase, the participants were instructed to cut out  500 calories a day. Half participants were given 1.5 ounces of mixed tree nuts as a snack, and the other half were given a calorically equal amount of pretzels.

After the first 12 weeks, both groups lost weight, regardless of which snack they were given. The researchers also found that participants taking nuts had increased satiety — the satisfaction of being full after eating — and decreased diastolic blood pressure (the measure of pressure in the arteries when the heart rests between beats).

During the second 12-week session, participants returned to their regular diets while continuing to eat their assigned snacks of either mixed nuts or pretzels. “We found that the people taking the mixed nuts were able to maintain their weight better than their counterparts who were eating pretzels,” Dr. Li said.

Wanting to go more in-depth with the findings, Dr. Li and her team did a further analysis. They analyzed the gathered fecal and blood samples from the participants to see if changes in the gut microbiome might link nut consumption to better cardiovascular health.

The study was partially funded by the International Tree Nut Council Nutrition Research & Education Foundation. 

More nuts = more serotonin = better mood

In addition to lowering blood pressure and increasing satiation, researchers found that nuts, with their high levels of fiber and polyphenol, have prebiotic qualities that can benefit human health by modulating the composition of the gut microbiome and reducing pathogenic bacteria.

Nuts also possess an essential amino acid called tryptophan, which contributes to the production of serotonin, a neurotransmitter associated with modulating our moods. “Participants in the study who ate nuts had higher levels of serotonin,” Dr. Li said. “When your serotonin levels are higher, you are, overall, in a happier mood.”

Learn more about nuts and nutrition.