What is the clinical evidence from this study?

Study design: RCT. Population: Hypercholesterolemia and healthy subjects (n=24). Intervention: Walnuts vs. Olive oil (25 g). Primary outcome: Flow-mediated dilation (FMD) (p=0.006).

What question did this study set out to answer?

To determine whether adding walnuts compared to olive oil to a high-fat meal differentially alters postprandial endothelial function, vasoactivity, oxidation markers, and inflammation.

July 31, 2026Journal of the American College of Cardiology

Acute Effects of High-Fat Meals Enriched With Walnuts or Olive Oil on Postprandial Endothelial Function

Q: What are the key findings of this study?

Adding walnuts to a high-fat meal acutely improved postprandial flow-mediated dilation compared to adding olive oil (P=0.006).

View Full Paper

Ask AI

Bookmark

Key result

Walnuts improve acute postprandial flow-mediated dilation compared to olive oil in a high-fat meal.

P=0.006
n=24

Why the study?

Does adding walnuts compared to olive oil to a high-fat meal improve postprandial endothelial function in healthy subjects and hypercholesterolemic patients?

Population

24 adults (12 healthy subjects and 12 patients with hypercholesterolemia)

Comparison

High-fat meal enriched with 40 g walnuts vs High-fat meal enriched with 25 g olive oil

Design

RCT, Randomized in a crossover design

Follow-up

4 hours post-meal

Authors

BCB. CortésUniversitat Autònoma de Barcelona INIsabel NúñezUniversity of Toronto MCMontserrat CofánThomas Jefferson University

Discussion

Member takes

Implication

Adding walnuts to a high-fat meal acutely preserves endothelial function better than olive oil in both healthy and hypercholesterolemic individuals.

Key Points

To determine whether adding walnuts compared to olive oil to a high-fat meal differentially alters postprandial endothelial function, vasoactivity, oxidation markers, and inflammation.
Conducted a randomized crossover trial involving 12 healthy subjects and 12 patients with hypercholesterolemia.
Participants ingested two high-fat meals (80 g fat, 35% saturated fatty acids) supplemented with either 40 g of walnuts or 25 g of olive oil, separated by a 1-week washout period.
Brachial artery ultrasound to measure flow-mediated dilation (FMD) and blood sampling were performed at fasting baseline and 4 hours postprandially.
Flow-mediated dilation was significantly better preserved after the walnut meal compared to the olive oil meal in both healthy and hypercholesterolemic participants (p = 0.006 for time-period interaction).
Soluble inflammatory cytokines and adhesion molecules generally decreased across both meals (p < 0.01), but E-selectin declined significantly more following the walnut meal (p = 0.033).
Plasma asymmetric dimethylarginine (ADMA) and flow-independent dilation remained unchanged, while oxidized low-density lipoprotein levels trended downward after both meals (p = 0.051).

Study Design

Type

RCT (n=24)

Randomization

Crossover

Structured PICO

Does adding walnuts compared to olive oil to a high-fat meal improve postprandial endothelial function in healthy subjects and hypercholesterolemic patients?

Population

24 healthy subjects and patients with hypercholesterolemia evaluated in a randomized crossover design comparing high-fat meals enriched with walnuts or olive oil.

Intervention

High-fat meal (80 g fat, 35% saturated fatty acids) enriched with 40 g walnuts

Comparator

High-fat meal (80 g fat, 35% saturated fatty acids) enriched with 25 g olive oil (administered in a crossover design separated by 1 week)

Outcome

Brachial artery endothelial function (flow-mediated dilation) measured by ultrasound 4 hours after test mealssurrogate

Main Result

p-value: p=0.006

Adding walnuts to a high-fat meal acutely preserves endothelial function better than olive oil in both healthy and hypercholesterolemic individuals.

Cite This Study

Cortés et al. (2006) conducted an RCT in Hypercholesterolemia and healthy subjects (n=24). Walnuts vs. Olive oil (25 g) was evaluated on Flow-mediated dilation (FMD) (p=0.006). Adding walnuts to a high-fat meal acutely improved postprandial flow-mediated dilation compared to adding olive oil (P=0.006).

synapsesocial.com/papers/6a6cbce5c767fbe144830fef https://doi.org/10.1016/j.jacc.2006.06.057

View Full Paper

Ask AI

Bookmark

Implication

Adding walnuts to a high-fat meal acutely preserves endothelial function better than olive oil in both healthy and hypercholesterolemic individuals.

Acute Effects of High-Fat Meals Enriched With Walnuts or Olive Oil on Postprandial Endothelial Function

Discussion

Member takes

Implication

Key Points

Study Design

Structured PICO

Main Result

Cite This Study

Acute Effects of High-Fat Meals Enriched With Walnuts or Olive Oil on Postprandial Endothelial Function

Discussion

Member takes

Implication

Key Points

Study Design

Structured PICO

Main Result

Cite This Study

Also Consider

Also Consider