Walnut intake linked to longer life in US adults
What it found
In two large groups of US adults followed for up to 20 years, those who ate walnuts more often were less likely to die during the study, especially from heart and blood vessel disease.
The link was seen in people, not in animals or cells.
What they found
Studies in people
Death from any cause
Compared with people who ate no walnuts, those who ate more walnuts had a lower risk of dying during the study. The risk dropped as walnut intake rose, from less than one serving a week up to five or more servings a week.
Heart and blood vessel deaths
People who ate more than five servings of walnuts a week had about a 25% lower risk of dying from cardiovascular disease than non-consumers. Each extra half serving a day was linked to a 14% lower risk of cardiovascular death.
Cancer deaths
Walnut consumption was not linked to cancer deaths after accounting for other factors.
Life expectancy at 60
The authors estimated that women who ate more than five servings of walnuts a week could gain 1.3 years of life expectancy at age 60, and men 1.26 years, compared with non-consumers. Those eating two to four servings a week gained 1.11 years for women and 0.96 years for men.
Diet quality
The link between walnut intake and lower death risk held regardless of overall diet quality. Among people with a suboptimal diet, each extra half serving a day was linked to a lower risk of total and cardiovascular death, but not cancer death.
What the authors conclude
“We reported that higher consumption of walnut was associated with a lower risk of all-cause mortality and CVD mortality in two large prospective studies of U.S. elder adults, especially among those with suboptimal dietary quality.”
Also in their conclusions
- They conclude that higher walnut consumption is associated with a lower risk of all-cause and cardiovascular mortality in older US adults, especially those with suboptimal dietary quality.
- They estimate a greater life expectancy at age 60 of 1.3 years in women and 1.26 years in men among those who consumed walnuts more than 5 servings per week compared to non-consumers.
- They suggest that incorporating walnuts into the diet may potentially contribute to improving overall dietary quality.
How it was done
The authors wanted to see whether walnut consumption was linked to death rates and to estimate how many extra years of life might be gained, because previous studies mostly reported relative risks that are hard for the public to understand.
They followed 67,014 women from the Nurses' Health Study and 26,326 men from the Health Professionals Follow-up Study, all free of cancer, heart disease and stroke at the start. Walnut intake was asked about every four years, and deaths were tracked for up to 20 years.
What it can’t tell you
- This was an observational study, so it can show a link between walnut intake and death rates, but it cannot prove that walnuts cause the lower risk.
- Walnut intake was self-reported, which may lead to some measurement error.
- The study population was limited to health professionals, so the results may not apply to everyone.
Who paid
- Conflicts
- Li has received research support from California Walnut Commission. The funder has no role in the design and conduct of the study, in the collection, analysis, and interpretation of the data, and in the preparation, review, or in the decision to publish the results. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Authors work at
- Harvard T.H. Chan School of Public Health, USA; Rush University Medical Center, USA; Brigham and Women's Hospital and Harvard Medical School, USA
The paper
- Title
- Association of Walnut Consumption with Total and Cause-Specific Mortality and Life Expectancy in U.S. Adults
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Liu X, Guasch-Ferré M, Tobias DK, Li Y (2021). Association of Walnut Consumption with Total and Cause-Specific Mortality and Life Expectancy in U.S. Adults. Nutrients. doi:10.3390/nu13082699Free full textPubMed 34444859DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error