A Handful of Walnuts a Day May Help Make Your Diet Less Inflammatory

A new study from Loma Linda University (LLU) School of Public Health, published in the Journal of the Academy of Nutrition and Dietetics, suggests that regularly incorporating walnuts into the diet may shift the overall diet pattern toward lower inflammatory potential.¹

The Dietary Inflammatory Index (DII) is a research tool that estimates whether a person's overall diet has characteristics associated with higher or lower inflammatory potential based on the foods and nutrients they consume.

The study, "The Dietary Inflammatory Index is Lower Among Healthy Older Adults Consuming a Walnut-Supplemented Diet. Ancillary Results from the Walnuts and Healthy Aging Randomized Controlled Trial," found that older adults who consumed 1-2 oz of walnuts (30-60 g) of walnuts daily had slightly but statistically significantly lower DII scores than those in the control group. The findings suggest that incorporating walnuts into the diet may shift the overall dietary patterns toward lower inflammatory potential.

These findings add to previous results from the Walnuts and Healthy Aging Study showing that daily walnut consumption was associated with reductions in several circulating markers of inflammation. Together, the findings suggest that adding walnuts to the diet may influence both the diet's inflammatory potential and biological markers of inflammation.

This latest report builds on data from more than 20 research papers published as part of the Walnuts and Healthy Aging Study, a major two-year clinical trial conducted by researchers at Loma Linda University School of Public Health and Hospital Clinic of Barcelona in Spain. The two teams have focused on investigating the effects of daily walnut consumption on older adults. The study was supported by a grant from the California Walnut Commission.

This most recent study followed 319 older adults from Loma Linda, California, for two years. Half were assigned to consume 1-2 ounces of walnuts daily, while the remaining control group participants abstained from walnuts while significantly limiting their consumption of other nuts. Neither group was instructed to make any additional dietary changes. Participants met with researchers five times during the two-year study and reported the food and beverages they had consumed during the previous 24 hours.

At the end of two years, participants who consumed walnuts had slightly but statistically significantly lower DII scores than those in the control group. Sujatha Rajaram, PhD, professor in the LLU School of Public Health, served as the study's senior investigator. "The important message is that incorporating nutrient-rich food such as walnuts is a simple and practical step towards shifting your dietary pattern to be less inflammatory," Rajaram said. "This illustrates how a relatively simple food choice can contribute to the overall diet quality."

"The important message is that incorporating walnuts into the diet was associated with a shift toward a less inflammatory dietary pattern," Rajaram said. "This illustrates how a relatively simple food choice can contribute to the overall quality of the diet."

Lynnley Heuy, DrPH, MPH, RD^, one of the study's primary co-authors, says the broader public health landscape increasingly emphasizes primary prevention and approaches that support healthier living.

"This study suggests that even a single dietary change-consuming one whole, plant-based food such as walnuts -may meaningfully reduce the inflammatory potential of the diet," Heuy said. "This highlights a simple and accessible step people can take as they pursue more inclusive and sustainable approaches to healthier lifestyles."

Jayme Brisco, MS, RD, the study's other co-primary author, says there are many ways to add walnuts to foods people already eat.

"Some people crush walnuts and add them to a salad," Brisco said. "Others add them to their breakfast cereals. But the simplest way might be eating a handful of walnuts as a snack each day, specifically replacing the snack foods that are full of sugar and refined carbohydrates."

Rajaram will present a symposium on nuts, focusing on several research findings surrounding their impact on diet and overall health, at the upcoming Eighth International Congress on Vegetarian Nutrition, a hybrid conference scheduled for March 14-16, 2027, in Loma Linda, California, and virtually.

References:

1. Stern LH, Brisco J, Jaceldo-Siegl K, Shavlik D, Sabate J, Serra-Mir M, Cofán M, Sala-Vila A, Ros E, Wirth MD, Hebert JR, Rajaram S. The Dietary Inflammatory Index is Lower Among Healthy Older Adults Consuming a Walnut-Supplemented Diet. Ancillary Results from the Walnuts and Healthy Aging Randomized Controlled Trial. J Acad Nutr Diet. 2026 Aug 28:156835. doi: 10.1016/j.jand.2026.156835. Epub ahead of print. PMID: 42665183.