Walnut consumption and heart structure over 25 years in young adults
What it found
People who ate walnuts had better measures of how the heart relaxes between beats than those who did not.
This was seen in 3,341 adults followed for 25 years.
What they found
Studies in people
Heart relaxation measures
People who ate walnuts had better scores on several tests of how the heart relaxes between beats. These values were still within normal ranges for both groups but were more favorable among walnut eaters.
Blood pressure and heart rate
Walnut eaters had lower resting blood pressure when the heart relaxes and a slower heart rate. Their blood pressure when the heart squeezes was slightly lower too.
Heart pumping strength
Tests measuring how well the heart pumps blood out showed no difference between people who ate walnuts and those who did not.
Amount eaten
The better heart relaxation and blood pressure readings were linked to eating an average of 0.70 ounce of walnuts each day across the study period.
Overall diet quality
People who ate walnuts also ate more fruit, vegetables, whole grains, and legumes. They ate less red meat, processed meat, and refined grains than non-consumers.
What the authors conclude
- They conclude that eating walnuts is linked to better heart relaxation measures in young to middle-aged adults.
- They suggest these findings support including walnuts as part of a regular diet.
- The authors note that compounds in walnuts may work together to help protect the heart over time.
How it was done
Walnuts contain nutrients like alpha-linolenic acid and melatonin that might support heart health. Scientists wanted to know if eating walnuts is linked to better heart structure and function over time.
Researchers followed 3,341 black and white adults who were 18 to 30 years old at the start. They asked about diet three times over 20 years. At year 25, they used ultrasound to measure heart structure and function.
What it can’t tell you
- Because this study followed people over time without assigning diets, it can only show a link, not prove walnuts caused the better heart measurements.
- People who ate walnuts also had healthier overall diets, which could partly explain the differences.
Who paid
- Funding
- Funded by NHLBI NIH HHS (from the PubMed record).
- Authors work at
- University of Minnesota, USA; University of Alabama at Birmingham, USA
The paper
- Title
- Walnut consumption and cardiac phenotypes: The Coronary Artery Risk Development in Young Adults (CARDIA) study
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Steffen LM, Yi SY, Duprez D, Zhou X, Shikany JM, Jacobs DR (2021). Walnut consumption and cardiac phenotypes: The Coronary Artery Risk Development in Young Adults (CARDIA) study. Nutrition, metabolism, and cardiovascular diseases. doi:10.1016/j.numecd.2020.09.001Free full textPubMed 33097410DOI
Summary written 1 Oct 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error