Almond Consumption and Glycemia

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03236116
Recruitment Status : Recruiting
First Posted : August 1, 2017
Last Update Posted : January 18, 2018
Almond Board of California
Information provided by (Responsible Party):
Richard Mattes, Purdue University

Brief Summary:
This study will examine the effects of almonds consumed by adults with different body fat distributions on indices of carbohydrate and lipid metabolism.

Condition or disease Intervention/treatment Phase
Glucose Intolerance Appetite Disorders Glucose Metabolism Disorders (Including Diabetes Mellitus) Lipid Metabolism Disorder Other: Almonds Other: Control (no nuts) Not Applicable

Detailed Description:

There is considerable evidence supporting a causal role for truncal visceral fat depots in glucose dysregulation. Individuals with large visceral fat depots have impaired suppression of free fatty acid release in response to insulin, elevated triglycerides and low concentrations of high density lipoprotein cholesterol. The high free fatty acid concentration may induce insulin resistance in the muscle and liver. There is more recent evidence that truncal subcutaneous fat depots are also problematic, though this literature is mixed. In contrast, gluteo-femoral fat depots have not been implicated in insulin resistance and dysregulation of carbohydrate metabolism. Failure to account for differences in the contributions of these depots will add noise to measurements of dietary interventions to mitigate glucose dysregulation. Previous studies have reported evidence indicating acute and chronic consumption of almonds improves glycemia. Acute effects are important indicators of health benefit, but longer-term trials, ones permitting identification of the effects of a dietary intervention on HbA1c, are more telling and clinically relevant. To more definitively establish the association between almond consumption and improved carbohydrate metabolism, we propose a six-month trial that contrasts the effects of almond consumption at optimal times of the day versus consumption of low nutrient dense snack foods on indices of carbohydrate metabolism, food intake and appetite in adults characterized by three distinct fat depots.

Participants will consume either almonds, or no nuts every day for 6 months. At baseline, participants will be weighed and undergo a DEXA scan to determine body fat composition and will be assigned a group. Blood will also be collected fasted and at stipulated times in response to a meal tolerance test to measure insulin, glucose, C-peptide, HbA1c, lipid panel, gut peptides, and compliance to the diet. Participants will be given links to complete appetite ratings and record food intake. Participants will report to the lab every two weeks to be weighed, and get a resupply of almonds (if in the almond group). At the two-week mark on months 2 and 4, participants will be weighed, blood will be taken to assess compliance to the diet, and links will be given to complete appetite ratings and record food intake. At month 6, all measurements from baseline will be repeated.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 120 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Almond Consumption and Glycemia
Actual Study Start Date : August 1, 2017
Estimated Primary Completion Date : July 31, 2019
Estimated Study Completion Date : July 31, 2019

Arm Intervention/treatment
Experimental: Almond Group
Participants will consumed almonds every day for 6 months.
Other: Almonds
Participants will consume almonds everyday for 6 months.

Experimental: Control Group
Participants will continue with their normal eating routine for 6 months, but will not be allowed to consume any nut products.
Other: Control (no nuts)
Participants will not be permited to consume any nuts for 6 months.

Primary Outcome Measures :
  1. HbA1c [ Time Frame: Baseline ]

  2. fasting glucose [ Time Frame: Baseline ]
    fasting glucose,

  3. fasting triglycerides [ Time Frame: Baseline ]
    fasting triglycerides

  4. Change in Body weight [ Time Frame: Every two weeks for 6 months. ]
    Body weight

  5. Body composition [ Time Frame: Baseline ]
    Body composition

  6. GLP-1 [ Time Frame: Baseline ]

  7. Change in HbA1c [ Time Frame: 6 months ]

  8. Change in fasting glucose [ Time Frame: 6 months ]
    fasting glucose

  9. fasting triglycerides [ Time Frame: 6 months ]
    fasting triglycerides

  10. Change in Body composition [ Time Frame: 6 months ]
    Body composition

  11. Change in GLP-1 [ Time Frame: 6 months ]

  12. fasting insulin [ Time Frame: Baseline ]
    fasting insulin

  13. total cholesterol [ Time Frame: Baseline ]
    total cholesterol

  14. LDL-cholesterol [ Time Frame: Baseline ]

  15. HDL-cholesterol [ Time Frame: Baseline ]

  16. GIP [ Time Frame: Baseline ]

  17. change in fasting insulin [ Time Frame: 6 months ]
    fasting insulin

  18. change in total cholesterol [ Time Frame: 6 months ]
    total cholesterol

  19. change in LDL-cholesterol [ Time Frame: 6 months ]

  20. change in HDL-cholesterol [ Time Frame: 6 months ]

  21. change in GIP [ Time Frame: 6 months ]

Secondary Outcome Measures :
  1. Diet Quality [ Time Frame: Three days (two non-consecutive week days and one weekend day) at baseline, month 2, 4, and 6. ]
    Determine the effect of substituting a wholesome snack food (almonds) for more traditional, less nutrient dense, snack foods on total diet quality. Food intake will be measured by the ASA-24 for three days (two non-consecutive week days and one weekend day) at baseline, month 2, 4, and 6.

  2. Compliance [ Time Frame: Baseline, month 2, 4, and 6. ]
    Demonstrate the utility of a novel, sensitive approach to document compliance with a prescription to ingest almonds on a daily basis for six months.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Meeting one of the following body fat distribution criteria determined by DEXA: 1. High visceral fat 2. High gluteo-femoral fat 3. High truncal subcutaneous fat
  • 18-60 years
  • no nut allergies

Exclusion Criteria:

  • Not meeting one of the body fat distribution criteria
  • allergic to nuts

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03236116

Contact: Richard D Mattes, PhD 765-494-0662
Contact: Stephanie R Hunter

United States, Indiana
Purdue University Recruiting
West Lafayette, Indiana, United States, 47907
Contact: Richard D Mattes, PhD, RD, MPH    765-494-0662   
Principal Investigator: Richard D Mattes, PhD, RD, MPH         
Purdue University Recruiting
West Lafayette, Indiana, United States, 47909
Contact: Richard D Mattes, Phd    765-494-0662   
Contact: Stephanie R Hunter    765-496-3607   
Sponsors and Collaborators
Purdue University
Almond Board of California
Principal Investigator: Richard D Mattes, PhD Purdue University

Responsible Party: Richard Mattes, Professor, Nutrition Sciences, Purdue University Identifier: NCT03236116     History of Changes
Other Study ID Numbers: 055-047
First Posted: August 1, 2017    Key Record Dates
Last Update Posted: January 18, 2018
Last Verified: January 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No

Additional relevant MeSH terms:
Diabetes Mellitus
Metabolic Diseases
Glucose Metabolism Disorders
Glucose Intolerance
Lipid Metabolism Disorders
Feeding and Eating Disorders
Pathologic Processes
Endocrine System Diseases
Mental Disorders