Nuts are not only good for the body but they may also influence how people feel, researchers in Spain have found.

Nutrition and food science Prof. Cristina Andres-Lacueva of the University of Barcelona and her team gave 22 people 30 grams of mixed almonds, walnuts and brazil nuts each day for 12 weeks. Nuts are good to have in the diet in moderation, nutrition specialists say. iStock

Another group of 20 men and women aged 31 to 63 was told to avoid nuts. All of the participants had metabolic syndrome —obesity around the midsection that puts them at risk of Type 2 diabetes and having a heart attack or stroke.

Almonds and other nuts have proven health benefits. They lower cholesterol, reducing the risk of heart disease, and they're full of fibre and nutrients that help people feel full longer

In a small study published in the Journal of Proteome Research, Andres-Lacueva reported evidence that nuts also improve mood.

"We found that people, after nut consumption, have higher levels of serotonin metabolites," she said.

Serotonin is a brain chemical that helps to regulate mood, appetite and sleep. It's known as a feel-good substance.

Nuts for snacking

It will take more study to confirm if nuts make people feel happier, said Prof. Laurie Wadsworth, a nutrition specialist at St. Francis Xavier University in Antigonish, N.S.

Wadsworth pointed out there's not much of a downside to eating nuts while waiting for the definitive research to be done.

"They're a good thing to have in our diet in moderation," Wadsworth said. "The trick is to get a 30-gram portion, which fits in the palm of most people's hands."

Dietitians caution though that nuts also have a lot of calories.

"It's a small, preliminary study, but it gives us insight into a different way of assessing how foods affect us," said CBC's medical specialist Dr. Karl Kabasele.

This new field of metabolomics could help people understand why foods are good for us or not good for us, he said.

The findings could also help partly explain why people who follow a Mediterranean diet rich in fruits and vegetables, fibre, fish and nuts tend to have healthier hearts, Kabasele added.

Eric Woolliscroft of Halifax is already a fan of nuts as a healthy alternative to snack foods.

"If I'm looking for that quick little fix, almonds tend to be what I go for," he said.

With files from CBC's Pauline Dakin