Effects of Pistachio Consumption on Body Composition and Blood and Bone Indicators
Condition: Healthy
Study type: Interventional

Summary: 
      Research investigating beneficial effects of regular pistachio feedings on body composition
      (BC) and blood lipids are limited, and there are no studies that have investigated the
      effects of feeding pistachios on bone density or membrane incorporation of fats. The purpose
      of this study is to examine the effects of pistachio consumption on body composition, bone
      density, markers of bone turnover, erythrocyte membrane incorporation of fatty acids, lipid
      status, inflammatory markers, dietary quality/micronutrients and satiety using a cross-over
      study with two 12-week treatment periods (pistachio added (20 percent of kcals) and a
      no-pistachio control diet), separated by 15-week washout period. The investigators will
      recruit 30 female students from Cal Poly, San Luis Obispo (CP-SLO) and female 30 students
      from Cal Poly, Pomona (CP-P) facilitating a collaborative project and using the expertise of
      both Dr. Laura Hall (CP-SLO) and Dr. Bonny Burns-Whitmore (CP-P). The investigators hope to
      show the health benefits of pistachios as part of an overall healthy lifestyle.
    

Detailed description: 
      Primary Research Objectives:

        1. To examine the effects of a diet rich in pistachios on body composition

        2. Examine incorporation of healthy fats into red blood cell (RBC) membranes

        3. Determine changes in blood lipids, inflammatory markers and markers of bone turnover
           with pistachio consumption

        4. Assess diet quality/micronutrient quality and satiety with pistachio consumption

      Methods Investigators will employ a crossover design with two 12-week treatment periods
      (pistachio added and a no-pistachio control diet), separated by 15-week washout period, with
      30 healthy students at each campus.

      Subjects Female students enrolled at CP-SLO and CP-P will be invited to participate in the
      study. The first 30 qualified females will be enrolled in the study at each site. A screening
      questionnaire will determine eligibility. The interview will take ~5 minutes. This sample
      size provides more than adequate power (80%) to detect individual changes.

      Recruitment Female students enrolled at CP-SLO and CP-P will be invited to participate in the
      study. Potential subjects will be notified by flyers, emails, adds on marquees, and peer
      recruitment in summer school classes. The information on the flyer and emails will be
      approved by the Institutional Review Boards and contain information regarding
      inclusion/exclusion criteria, length of study, and the risks and benefits. Participants will
      be asked to contact either Dr. Laura Hall (CP-SLO) or Dr. Bonny Burns-Whitmore (CP-P) and
      then potential participants will be asked to fill out a screening questionnaire to determine
      eligibility.

      Study Design & Methods We will employ a randomized crossover design with two 12-week
      treatment periods: pistachio added (20% of kcals) and a no-pistachio control diet), separated
      by 15-week washout period, with 30 healthy female students at each campus. The first
      treatment period will be in Fall 2012 and the second treatment period will be in Spring 2013.

      Randomization to treatment (pistachios) or habitual (control) diet and 24-hour recalls
      Randomization will be done utilizing a www.randomization.com list of random appointments to
      either the treatment group first or the control group first.

      Materials and Procedures:

      Study visits: Participants will come to the CP-SLO (n=30) or CP-P (n=30) site once a week
      during Fall quarter for 12 weeks and again during Spring quarter for 12 weeks to pick up
      their pre-measured pistachios for a total of 24 total study visits. At the initial visit,
      half the participants will be given pistachios to include in their diet as snacks or in meals
      (20 percent of kcals; intervention group) while half will continue their normal diets
      (control group). During, Spring, the other half of the participants will switch and consume
      the pistachios while the first half will not. Diet counseling will also be given at these
      visits and compliance to study protocols will be evaluated by counting the number of
      pistachio packages and looking at the participant's Unusual Diet Diary. At baseline and end
      of each treatment period, participants will have their height, weight, waist circumference,
      hip circumference, body composition measured and blood drawn at both sites. At CP-SLO they
      will also have their bone density measured (DXA). At the CP-P site they will have a fatty
      acid analysis performed to examine monounsaturated fatty acid incorporation into red blood
      cells (RBCs).

      Calculation/Distribution of Pistachios and Initial/Weekly Study Visits During the lead-in
      period participants will meet initially and will be trained on keeping their food records by
      a Registered Dietitian (RD). During this week they will each keep a 3-day food record and
      turn it in immediately. The researchers will calculate how many pistachios each participant
      needs based off of the initial 3-day food record. This amount will be substituted as 20
      percent of their usual caloric need and it will be pre-measured into daily
      individually-wrapped servings. The researches will meet with the participants weekly to give
      them a week's supply of their pre-measured packet of pistachios (one for each day). They will
      be asked to bring in their used wrappers to the weekly counseling meetings. At the weekly
      counseling meetings, participants will be shown how to incorporate the pistachios into their
      diet (either as snacks or in recipes) in an isocaloric diet, to check the participant's
      unusual diet diary and food records for accuracy, to review the 'MyPlate' guidelines and to
      check the empty pistachio wrappers for compliance. Participants will also get email/text
      reminders about meetings and reminder instructions on how to prepare for study visits.

      Data Collected at both sites during Fall 2012 (wk 1 and wk 12) & Spring 2013 (wk 1 and wk
      12):

      Anthropometric Measurements: Body weight will be measured using a calibrated scale and
      recorded to the nearest 0.1 kg. Height will be measured using a stadiometer and recorded to
      the nearest 0.1 cm. Body mass index (BMI) will be calculated as weight (kg) divided by height
      (m) squared. Waist circumference will be measured using a flexible measuring tape between the
      middle of the bottom rib and iliac crest (top of the hip bone) and recorded to the nearest
      0.1 cm. Hip circumference will be measured using a flexible measuring tape around the largest
      part of the hips (i.e. buttocks) and recorded to the nearest 0.1 cm. Measurements will be
      taken twice and averaged. We will also calculate their waist-to-hip ratio. Protocols will be
      based on NHANES III standardized procedures and student volunteers will be thoroughly trained
      on these protocols (see link-NHANES) Blood Pressure: Blood pressure will be taken using an
      automatic blood pressure monitor. Protocol will be based on Mayo Clinic standardized
      procedures and student volunteers will be thoroughly trained on these protocols (see
      link-Mayo Clinic).

      Body Composition Measurement: Body fat percentage will be assessed by bioelectrical impedance
      analysis using the Tanita Body Composition Analyzer Scale (model TBF-310); from Tanita
      Corporation, (Tokyo, Japan). It will also be used to measure weight, body mass index (BMI),
      percent body fat, impedance, fat mass (TBF), fat free mass (FFM), total body mass (TBM), and
      total body water (TBW). The participants will need to fast for 12 hours before their study
      visit (i.e. no caffeine in the morning but 1.5 cups of water prior to the visit will be
      encouraged).

      Food Records/Unusual Diet Diary (ie. Dietary Adherence & Compliance): Adherence and
      compliance to the assigned diets will be assessed using an Unusual Diet Diary (developed at
      CP-P), which is filled out by the participant when unusual quantities of foods or accidental
      pistachio consumption occurs, medical treatment is required, a suspected allergic
      reaction/side effect occurs or pharmaceuticals are consumed. If a participant experiences an
      allergic reaction to pistachios they will have been told to call 911 and after contacting the
      researchers, they will be removed from the study to limit further risk. Food records will be
      administered during each treatment to obtain information regarding the subject's diet and
      determine if the subject is adhering to treatment protocols. Participants will be thoroughly
      trained on how to keep accurate food records. Participants will be asked to perform 9
      randomly selected food records throughout the study. Investigators will use the Nutrition
      Data System for Research (NDSR) from the University of Minnesota on both campuses for the
      diet analysis software (see NDSR link).

      Satiety and Hunger ratings: Participants will rate their hunger using a rating scale (1-10)
      before, during and after each snack or meal directly on their 9 required food records during
      each treatment, and will use a validated visual analog scale (VAS) to rate their hunger after
      consuming their snack or meal with pistachios for the intervention group and randomly chosen
      snacks/meals for the control group. Participants will be given binders with the food record
      forms and VAS questionnaires in them with the randomly chosen dates and instructions listed.
      Completed forms will be checked for accuracy and collected at the weekly visits from the
      binders.

      Physical Activity Questionnaire: Participants will be asked to recall their physical activity
      level over the preceding week (7 day recall) using the 2002 International Physical Activity
      Questionnaire (IPAQ) short form. Participants will be encouraged to maintain their usual
      levels of physical activity.

      Chem Panel/Iron Panel/Blood Lipids: Blood will be drawn on campus at the Health Center at
      week 1 and 12 to examine a lipid panel, a standard chem. panel and iron status. The
      participants will need to fast for 12 hours before the blood draw, however, consuming 1.5
      cups of water in the morning will be encouraged.

      Inflammatory Markers: Blood will be drawn on campus at the Health Center at week 1 and 12 to
      examine inflammatory markers (ie, C-reactive protein (CRP), tumor necrosis factor alpha
      (TNFa), and interleukin-6 (IL-6)). The participants will need to fast for 12 hours before the
      blood draw, however, consuming 1.5 cups of water in the morning will be encouraged.

      Markers of Bone Turnover: Blood will be drawn on campus at the Health Center at week 1 and 12
      to examine markers of bone turnover.

      Data Collected at the Cal Poly, SLO site only :

      Body Composition/Bone Mineral Density (DXA): Full-body DXA (iDXA, General Electric
      Healthcare) will be used to determine body fat mass, body fat percentages, lean body mass and
      bone mineral density of each subject. A pregnancy test will be given to participants before
      the test to ensure safety of the fetus. If positive, the participant will be asked to
      terminate their participation in the study.

      Data Collected at the Cal Poly, Pomona site only:

      Erythrocyte Membrane Incorporation (Lipomics): Erythrocytes membranes will be measured for
      all fatty acids. Erythrocytes will be packed in dry ice and shipped overnight to Lipomics
      Technologies, West Sacramento, California 95691.

      Data Analysis: A statistician will be consulted and all statistical analyses will be
      conducted using Statistical Analysis Software (SAS version 9.2). Time-repeated analysis of
      variance (ANOVA) will be performed for comparisons between the variables during the two time
      points and ANOVA's will be performed between the two treatment groups. Spearman's correlation
      will be used to examine associations between the variables.

      Debriefing of Participants: Subjects will be consented to this study and will be aware of the
      purpose of this study. All subjects will be given a copy of the consent form.

      Results Dissemination Plan

      The dissemination plan for the results of this project includes but is not limited to:

        -  Publication in peer-reviewed journals (i.e. Journal of Nutrition, The Journal of
           Clinical Nutrition, The Journal of the Academy of Nutrition and Dietetics (AND), the
           American Journal of Public Health, Journal of Family and Consumer Science).

        -  Publication in newsletter articles and research bulletins

        -  Publication on the Cal Poly Pomona web site, Agriscapes, e-mail announcements,
           presentation at poster sessions

        -  Presentation at scientific meetings (i.e. Experimental Biology).
    

Intervention name(s): Pistachio added 20% of kcals to diet
Intervention type(s): Other
Intervention description(s): Pistachio added 20% of kcals to diet
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Keywords: Pistachio; Body composition; Erythrocyte membrane incorporation of fatty acids; Dietary quality/micronutrient quality; Blood lipids; Inflammatory markers; Bone density; Bone turnover markers; Satiety