A pecan a day keeps bad cholesterol away

By Dr. Priyom Bose, Ph.D.Reviewed by Benedette Cuffari, M.Sc.Mar 24 2025

A 12-week clinical trial reveals that swapping your usual snacks for a daily handful of pecans can improve cholesterol and overall diet quality—offering a heart-smart upgrade without harming vascular health.

Study: Consuming pecans as a snack improves lipids/lipoproteins and diet quality compared with usual diet in adults at increased risk of cardiometabolic diseases: A randomized controlled trial. Image Credit: SherSor / Shutterstock.com

A recent American Journal of Clinical Nutrition study finds that consuming 57 grams of pecans daily for 12 weeks improves lipids/lipoproteins levels and diet quality but fails to influence vascular health in adults at high risk of cardiometabolic disease.

How snacks impact heart health and metabolism

In the United States, approximately 45% of deaths associated with cardiometabolic disease have been attributed to poor diet quality. Thus, long-term adherence to healthy dietary patterns could effectively reduce the risk of death due to cardiometabolic diseases.

Snacks are important meals, as they provide about 20% of daily total energy intake. However, individuals who consume snacks with higher added sugar and saturated fat content often have poorer overall diet quality than those who consume nutrient-rich foods while snacking. This suggests that replacing nutrient-poor snack foods with nutrient-rich alternatives could improve diet quality and health status.

Nuts as a healthy snack

Nuts are nutrient-rich foods that can be used as snacks to replace unhealthy foods. Multiple epidemiologic studies have associated nut intake with a reduced risk of cardiovascular disease (CVD). Similarly, several clinical trials have reported that nut intake improves CVD risk factors, particularly triglycerides, glycemic index, low-density lipoprotein (LDL) cholesterol, and endothelial function in adults diagnosed with various health conditions.

Compared to other nuts, pecans have a higher polyphenol content, including flavan-3-ol. High flavan-3-ol intake has been shown to reduce the risk of coronary artery disease and cardiovascular mortality. This polyphenol also improves endothelial function measured by flow-mediated dilation (FMD).

Pecan consumption has also been associated with improved lipid and lipoprotein levels compared to non-nut snacks. However, this finding was contradicted by one clinical trial reporting no positive effect of pecan consumption based on FMD in older adults. These contradictory results warrant additional studies to clarify the impact of pecans on CVD health.

About the study

The current single-blind, randomized, parallel, and controlled clinical trial was conducted at Pennsylvania State University between August 2022 and March 2024. The researchers hypothesized that consuming 57 grams of raw and unsalted pecans daily would improve FMD, lipids/lipoproteins, arterial stiffness, and glycemic control compared to those who continued consuming their usual diet.

All eligible participants were randomly assigned in a 1:1 ratio to the pecan snack group or usual diet group. Both male and female participants were between 25 and 70 years of age with excess weight or obesity. All study participants possessed at least one metabolic syndrome at screening.

Individuals who were allergic or sensitive to pecans, used tobacco within the last six months of the study commencement, and had a history of cardiovascular events or heart failure, type 2 diabetes, or other conditions were not eligible for study participation.

Vascular and cardiometabolic outcomes were assessed at baseline and after 12 weeks of intervention. Diet quality was measured at baseline, week 6, and week 12.

Study findings

Overall, 59% of study participants were female, had an average age of 46 years, and an average body mass index (BMI) of 29.8 kg/m². At baseline, 38 study participants met the criteria for metabolic syndrome, and 89% reported snack intake on the 24-hour recall survey. Energy intake from snacks was similar between the groups.

In the pecan group, study participants consumed pecans as a snack for a median of 100% of study days. At week 12, neither study group was significantly associated with FMD or any secondary vascular measure.

At 12 weeks, the pecan group increased its weight by a mean of 0.85 kg compared to baseline levels. Individuals in the pecan group who gained weight exhibited a greater decrease in pulse pressure than those who gained weight in the usual diet group. No intervention heterogeneity was observed for cardiometabolic risk factors by weight change status in either group.

Pecan consumption led to improvements in total cholesterol, LDL cholesterol, triglycerides, and non-high-density lipoprotein (HDL) cholesterol levels as compared to the usual diet group after 12 weeks. After 12 weeks, the pecan group consumed more total fat, monounsaturated fat, polyunsaturated fat, and fiber than the usual diet group. Study participants consuming pecans also consumed less energy from carbohydrates.

Pecan consumption was associated with improvements in overall diet quality, as assessed by the Healthy Eating Index (HEI)-2020. After 12 weeks, HEI-2020 scores were 9.4 points higher in the pecan group than in the usual diet group.

Conclusions

Pecan consumption was found to improve lipids/lipoproteins and diet quality, which could positively reduce CVD risks in adults who are at an increased risk of developing cardiometabolic diseases. Although pecan consumption did not affect vascular health, the current study's researchers recommend replacing usual snacks with 57 grams/day of pecans.