Almonds to Improve Gut Health and Decrease Inflammation

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: Active, not recruiting
• Conditions: Inflammation; Metabolic Syndrome; Dysbiosis
• Intervention / Treatment: Other: Almond; Other: Crackers

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: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Gut permeability and health: Serum endotoxin	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	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	Change from baseline at week 4: Gut inflammatory biomarkers calprotectin and myeloperoxidase	0 and 4 weeks
Biomarkers of inflammation	Change from baseline at week 4: Plasma inflammatory markers (ex. TNF and IL-6)	0 and 4 weeks
Oxidative stress status: malondialdehyde	Change from baseline at week 4: Plasma malondialdehyde	0 and 4 weeks
Oxidative stress status: isoprostanes	Change from baseline at week 4: Urinary isoprostanes	0 and 4 weeks
Cardiometabolic health	Change from baseline at week 12: Total cholesterol, LDL, HDL, and triglycerides	0 and 12 weeks
Vitamin E status	Change from baseline at week 4 and week 12: Plasma α-tocopherols	0, 4 and 12 weeks
Vitamin E status: Urinary catabolite	Change from baseline at week 4 and week 12: Urinary vitamin E catabolite (α-CEHC)	0, 4 and 12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure	Change from baseline at week 4 and week 12: Systolic, and diastolic blood pressure	0, 4 and 12 weeks
Weight	Change from baseline at week 4 and week 12: Weight	0, 4 and 12 weeks
BMI	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	Change from baseline at week 4 and week 12: Waist circumference	0, 4 and 12 weeks
Glycemic control: glucose	Change from baseline at week 12: Fasting blood glucose	0 and 12 weeks
Glycemic control: Insulin	Change from baseline at week 12: Insulin	0 and 12 weeks
Glycemic control: HOMA-IR	Change from baseline at week 12: HOMA-IR	0 and 12 weeks
Other almond-based bioactives (polyphenol levels)	Change from baseline at week 12: Urinary metabolites of flavonoids like (+)-catechin, (-)-epicatechin and naringenin	0 and 12 weeks
Mineral status	Change from baseline at week 12: Plasma magnesium, calcium, iron, zinc, and copper (microgram/mL)	0 and 12 weeks

Collaborators and Investigators

• Sponsor: Oregon State University
• Investigators: Principal Investigator: Laura Beaver, PhD, Oregon State University

Study record dates

Study Major Dates

• Study Start (Actual): November 17, 2022
• Primary Completion (Actual): October 1, 2024
• Study Completion (Estimated): July 1, 2027

Study Registration Dates

• First Submitted: March 3, 2023
• First Submitted That Met QC Criteria: March 16, 2023
• First Posted (Actual): March 30, 2023

Study Record Updates

• Last Update Posted (Actual): May 5, 2026
• Last Update Submitted That Met QC Criteria: April 29, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Metabolic Diseases; Glucose Metabolism Disorders; Insulin Resistance; Hyperinsulinism; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Metabolic Syndrome; Inflammation; Dysbiosis
• Other Study ID 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