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A new study suggests that people who eat walnuts tend to have a lower risk of heart disease and healthier eating habits. Westend61/Getty Images
  • Nuts, including walnuts, are generally considered part of a healthy diet because of their high levels of protein, fiber, and healthy fats.
  • Researchers from the University of Minnesota found that people who consume walnuts have a better heart disease risk profile than those who do not eat walnuts.
  • The research team also reported walnut eaters ate an overall healthier diet, gained less weight, and enjoyed more physical activity compared to non-walnut eaters.

Nuts are generally considered a part of a balanced diet due to their high levels of protein, fiber, and healthy fats.

New research from the University of Minnesota spotlights one nut in particular — walnuts.

The findings suggest that those who include this particular nut in their diet enjoy certain health benefits, including less weight gain, a higher quality diet, and a better heart disease risk profile.

This study, which was partially funded by the California Walnut Commission, was recently published in the journal Nutrition, Metabolism & Cardiovascular Diseases.

Although walnuts are commonly considered to be a nut, they are technically the seed of a fruit.

Walnut trees grow the stone fruit, also called a drupe. As the fruit matures, the outside turns into a hard shell, housing the edible seed — the walnut — inside.

A daily serving of walnuts is equivalent to 1 ounce, 1/4 cup, or 12-14 walnut halves, and has a nutrition breakdown of:

  • 190 calories
  • 18 grams of fat (including 13 grams of polyunsaturated fat)
  • 4 grams of carbohydrates
  • 4 grams of protein
  • 2 grams of dietary fiber
  • 1 gram of sugar
  • No sodium or cholesterol

According to Lauren Pelehach Sepe, a clinical nutritionist at the Kellman Wellness Center in New York, NY, walnuts are some of the healthiest nuts you can eat.

“They are rich in healthy fats, antioxidants, as well as several essential minerals,” she explained to Medical News Today. “Given their beneficial nutritional profile, walnuts are an important part of a healthy diet, as they provide a number of crucial health benefits.”

Sepe said that walnuts offer more health benefits compared to other nuts because they contain the highest amount of omega-3 fatty acids — also known as n-3 fatty acids — of any nut.

“Omega-3 fatty acids are naturally anti-inflammatory. They also have been shown to lower triglyceride levels and reduce plaque formation, which is one mechanism by which they lower your risk of cardiovascular disease.”

– Lauren Pelehach Sepe, clinical nutritionist

Sepe also cited a 2019 study showing that walnuts help provide cardiovascular benefits due to their impact on the gut microbiota.

“A healthy gut microbiome has been linked to reduced inflammation levels, which reduces your risk of cardiovascular disease, as well as improves your lipid profile, decreases your risk of metabolic disease, as well as many other health benefits,” she added.

For the current study, senior author Lyn Steffen, PhD, MPH, professor of epidemiology and community health at the University of Minnesota School of Public Health, said the main objective was to determine if walnut consumers had a better diet pattern and better cardiovascular risk factor profile over 30 years of follow-up, compared to those who did not eat walnuts.

For this observational study, Dr. Steffen and her team utilized findings from the Coronary Artery Risk Development in Young Adults (CARDIA) study, which began during 1985-1986 with a group of over 5,000 Caucasian and Black men and women ages 18 to 30 years old, and is ongoing today.

The research team examined data for 3,023 CARDIA participants that included 352 walnut eaters, 2,494 eaters of other nuts, and 177 non-nut eaters.

Upon examination of physical and clinical measurements after 30 years, researchers found walnut eaters showed a better heart disease risk profile, including:

Researchers also determined that people who consumed walnuts ate a healthier overall diet, gained less weight, tested with a lower fasting blood glucose concentration, and self-reported more physical activity.

Dr. Steffen said the findings were not surprising because walnuts are an excellent source of plant n-3 fatty acids, more specifically alpha-linolenic acid (ALA) and other antioxidants.

“Other nuts are also nutritious and contain fatty acids and antioxidants, but other types of nuts do not contain ALA, plant-based n-3 fatty acids,” she explained to MNT.

“I have read about the health benefits of walnuts for many years — I wanted to see if walnut consumption would be related beneficially to CVD [cardiovascular disease] health profiles in the CARDIA population.”

“I wrote another paper about walnut consumption associated with cardiac phenotypes — this is systolic and diastolic function — using data from the CARDIA study. Even though the adults’ cardiac function parameters were within normal ranges, adults who consumed walnuts had better values.”

– Lyn Steffen, PhD, MPH, lead author of the study

According to Sepe, there is no exact answer to determine how many walnuts a person should eat a day to enjoy the health benefits outlined in the study.

Still, she suggested that 1 ounce a day, which is about seven walnuts or 14 walnut halves, can provide benefits.

“They are easy to add to your daily diet, or you can have a larger serving several times a week,” she explained. “The goal is not so much a specific number, but to start including these and other nutrient-dense foods into your diet daily to confer maximum benefits.”

As for the next steps in this research, Sepe said she would like to see more research looking at all the mechanisms by which walnuts provide health benefits, namely their impact on the gut.

“This could lead to not only a better understanding of how walnuts may reduce the risk of cardiovascular disease but other health conditions as well,” she added.