Snacking on pecans helps enhance diet quality in adults at risk of cardiometabolic diseases

Consuming pecans as an alternative to usual snacks may improve lipids/lipoproteins and diet quality in adults at increased risk of cardiometabolic diseases, suggests a study. However, pecan intake does not appear to have any effect on vascular health.

“Recommendations to replace usual snacks with pecans in those at increased cardiometabolic risk may assist in lowering cardiovascular disease risk through improvements in diet quality and lipids/lipoproteins,” the investigators said.

One hundred thirty-eight participants (mean age 46 years, mean BMI 29.8 kg/m²) were randomly allocated to the pecan (n=69) or control group (usual diet; n=69). No significant difference was observed in flow-mediated dilation (FMD), the primary outcome, between the two groups, as well as in carotid-femoral pulse wave velocity (cf-PWV) or blood pressure. [Am J Clin Nutr 2025;121:769-778]

Compared with usual diet, pecan consumption resulted in a decrease in total cholesterol (‒8.1 mg/dL, 95 percent confidence interval [CI], ‒14.5 to ‒1.7), low-density lipoprotein (‒7.2 mg/dL, 95 percent CI, ‒12.3 to ‒2.1), nonhigh-density lipoprotein cholesterol (‒9.5, 95 percent CI, ‒15.3 to ‒3.7), and triglycerides concentrations (‒16.4 mg/dL, 95 percent CI, ‒30.0 to ‒2.9).

Participants in the pecan group tended to have a weight increase relative to those in the control group (0.7 kg, 95 percent CI, ‒0.1 to 1.4). In addition, a 9.4-point increase (95 percent CI, 5.0‒13.7) in the Healthy Eating Index (HEI)-2020 was observed in the pecan group compared with the control group.

“Replacing usual snacks with 57 g/day of pecans improved lipids/lipoproteins and adherence to the Dietary Guidelines for Americans 2020–2025 compared with continuing usual intake after 12 weeks in adults at risk of cardiometabolic diseases,” the investigators said.

Polyphenols

A previous study suggests that polyphenols, particularly flavan-3-ols, may boost endothelial function by increasing the production of nitric oxide via endothelial nitric oxide synthase and reducing nitric oxide inactivation by superoxides. [Nutrients 2022;14:545]

Estimates show that the provided daily dose of pecans contain ∼9 mg flavan-3-ols. This is much lower than dosages (>34 mg) shown to improve FMD previously. [Asia Pac J Clin Nutr 2010;19:117-123; Am J Clin Nutr 2019;110:1067-1078]

“Recently, an expert panel proposed a recommendation for flavan-3-ols based on moderate evidence that intake of 400–600 mg/day of flavan-3-ols supports cardiometabolic protection,” the investigators said. “Thus, it is possible we saw no effect of 57 g/day of pecans on FMD, cf-PWV, or blood pressure because the dose of flavan-3-ols was too low.” [Adv Nutr 2022;13:2070-2083]

The current 12-week single-blinded, parallel, randomized controlled trial involved adults meeting at least one criterion for metabolic syndrome who were free from cardiovascular disease and type 2 diabetes. Participants received 57 g/day of pecans and were asked to replace their usual snacks with the provided pecans. On the other hand, control participants were instructed to continue their usual diet.

The investigators measured FMD, cf-PWV, blood pressure, lipids/lipoproteins, and glycaemic control at baseline and following the intervention. They also calculated the HEI-2020 to assess diet quality. Participants completed three 24-h recalls at baseline, week 6, and week 12 during the study.