Almonds to Improve Gut Health and Decrease Inflammation

April 29, 2026 updated by: Laura Beaver, Oregon State University

Almonds to Improve Gut Health and Decrease Inflammation in Metabolic Syndrome

Almonds are a good source of beneficial compounds. This study will investigate if eating almonds everyday for 12 weeks can affect gut health and inflammation in persons with metabolic syndrome. Investigators will measure changes in metabolism, heart health, and the levels of vitamins and other compounds from almonds.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Metabolic Syndrome (MetS) affects over a billion people world-wide. MetS progression and further health complications are driven by chronic inflammation. Major causes of inflammation in MetS are gut barrier breakdown and the absorption of harmful bacteria. What causes the gut barrier breakdown is not clear, but a poor diet, especially low micronutrient intakes like vitamin E, is implicated by propagating a vicious cycle that promotes oxidative stress, inflammation and further gut barrier damage. This study will assess the impact of daily consumption of 2 ounces of almonds for 12 weeks on gut health, markers of inflammation and cardiometabolic health, and micronutrient status in persons with MetS.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
80

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Oregon
      • Corvallis, Oregon, United States, 97331
        • Oregon State University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

35 years to 60 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age 35-60 years
  • 3 or more of the following: hypertension (systolic BP 130-179 mmHg or diastolic BP 85-119 mmHg); hyperglycemia (fasting glucose 100-599 mg/dL); central obesity [waist circumference greater than 40.1 inches (M) or 34.6 inches (F); hypertriglyceridemia (150-499 mg/dL); low HDL [lower than 40 mg/dL (M) or 50 mg/dL (F)]
  • Willing to restrict consumption of nuts other than study nuts for 1 week prior to and throughout the study (13 weeks)
  • Willing to stop probiotic supplements one week prior to and during the study (13 weeks)
  • Willing to stop multivitamins and supplements containing vitamin E, magnesium, calcium, iron, zinc and copper one week prior to and during the study (13 weeks)
  • Willing to complete intake diaries during the study
  • Willing to maintain current eating patterns (no significant diet change during study)

Exclusion Criteria:

  • Weekly consumption of almonds, hazelnuts, peanuts and sunflower seeds combined greater than 2 servings (about 2 oz) in the past 3 months
  • Nut, wheat, or gluten allergy/intolerance
  • Regular use of vitamin E supplements
  • Consume more than 2 alcoholic drinks daily
  • Tobacco use, including e-cigarettes, or smoking of any substance (e.g. cannabis) in the past 3 months
  • Pregnancy, breastfeeding, or planning to become pregnant before completing the study
  • Vigorous exercise greater than 7 hours/week
  • History of cardiovascular disease, liver disease or cancer
  • Have had bariatric surgery (e.g. gastric bypass, gastric banding, sleeve gastrectomy, etc.), other gastrointestinal procedures (e.g. cholecystectomy), disorders (e.g. Crohn's disease, celiac disease, ulcerative colitis) or chronic diarrhea
  • Diagnosis of hemochromatosis
  • Chronic use (daily intake in past 30 days) of anti-inflammatory medication (steroid or NSAID)
  • Use of ezetimibe or orlistat
  • Use of oral antibiotic medication within the past month
  • Body Mass Index (BMI) <25.0 or >35.0 kg/m2
  • Regular use of multivitamin supplements in the past 3 months
  • Physician prescribed use of probiotic, vitamin E, magnesium, calcium, iron, zinc or copper supplements

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Almonds
Daily consumption of 2 ounces of unsalted, dry roasted almonds for 12 weeks
Other: Almond
Daily consumption of 2 ounces of unsalted, dry roasted almonds for 12 weeks
Placebo Comparator: Crackers
Daily consumption of non-whole grain crackers for 12 weeks (caloric equivalent to 2 ounces of dry roasted almonds)
Other: Crackers
Daily consumption of non-whole grain crackers for 12 weeks (caloric equivalent to 2 ounces of dry roasted almonds)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Gut permeability and health: Serum endotoxin
Time Frame: 0 and 4 weeks
Change from baseline at week 4: Marker of gut barrier function and health, serum endotoxin
0 and 4 weeks
Gut permeability and health: Short chain fatty acids
Time Frame: 0 and 4 weeks
Change from baseline at week 4: Markers of gut barrier function and health fecal short chain fatty acids profiles
0 and 4 weeks
Gut permeability and health: Inflammatory biomarkers
Time Frame: 0 and 4 weeks
Change from baseline at week 4: Gut inflammatory biomarkers calprotectin and myeloperoxidase
0 and 4 weeks
Biomarkers of inflammation
Time Frame: 0 and 4 weeks
Change from baseline at week 4: Plasma inflammatory markers (ex. TNF and IL-6)
0 and 4 weeks
Oxidative stress status: malondialdehyde
Time Frame: 0 and 4 weeks
Change from baseline at week 4: Plasma malondialdehyde
0 and 4 weeks
Oxidative stress status: isoprostanes
Time Frame: 0 and 4 weeks
Change from baseline at week 4: Urinary isoprostanes
0 and 4 weeks
Cardiometabolic health
Time Frame: 0 and 12 weeks
Change from baseline at week 12: Total cholesterol, LDL, HDL, and triglycerides
0 and 12 weeks
Vitamin E status
Time Frame: 0, 4 and 12 weeks
Change from baseline at week 4 and week 12: Plasma α-tocopherols
0, 4 and 12 weeks
Vitamin E status: Urinary catabolite
Time Frame: 0, 4 and 12 weeks
Change from baseline at week 4 and week 12: Urinary vitamin E catabolite (α-CEHC)
0, 4 and 12 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Blood pressure
Time Frame: 0, 4 and 12 weeks
Change from baseline at week 4 and week 12: Systolic, and diastolic blood pressure
0, 4 and 12 weeks
Weight
Time Frame: 0, 4 and 12 weeks
Change from baseline at week 4 and week 12: Weight
0, 4 and 12 weeks
BMI
Time Frame: 0, 4 and 12 weeks
Change from baseline at week 4 and week 12: BMI (weight and height will be combined to report BMI in kg/m^2)
0, 4 and 12 weeks
Waist circumference
Time Frame: 0, 4 and 12 weeks
Change from baseline at week 4 and week 12: Waist circumference
0, 4 and 12 weeks
Glycemic control: glucose
Time Frame: 0 and 12 weeks
Change from baseline at week 12: Fasting blood glucose
0 and 12 weeks
Glycemic control: Insulin
Time Frame: 0 and 12 weeks
Change from baseline at week 12: Insulin
0 and 12 weeks
Glycemic control: HOMA-IR
Time Frame: 0 and 12 weeks
Change from baseline at week 12: HOMA-IR
0 and 12 weeks
Other almond-based bioactives (polyphenol levels)
Time Frame: 0 and 12 weeks
Change from baseline at week 12: Urinary metabolites of flavonoids like (+)-catechin, (-)-epicatechin and naringenin
0 and 12 weeks
Mineral status
Time Frame: 0 and 12 weeks
Change from baseline at week 12: Plasma magnesium, calcium, iron, zinc, and copper (microgram/mL)
0 and 12 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Oregon State University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Laura Beaver, PhD, Oregon State University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 17, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
October 1, 2024

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 3, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 16, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 30, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 5, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 29, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • LPI-2022-1435

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared with other researchers without IRB approval.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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