Effect of Dried Fruit Intake on Acid-base Balance

Effect of Dried Fruit Intake on Acid-base Balance in Community Dwelling Adults

Most adults consume acid-producing diets because their high intake of protein and/or cereal grains in relation to their intake of fruits and vegetables. This study is being done to determine whether acid-base balance can be restored by the addition of dried fruits to the diet. In this study adults with low usual fruit intake will be provided with either 100 g per day of a mix of dried fruits or no dried fruit. Participants will be followed for 1 year. Acid-base status will be assessed by measuring the acid content in 24-hour urine collections.

Study Overview

• Status: Terminated
• Conditions: Acid-Base Balance Disorder
• Intervention / Treatment: Other: food - dried fruit

Detailed Description

Most adults consume acid-producing diets because their intake of protein and/or cereal grains is high in relation to their intake of fruits and vegetables. Supplementation with alkaline salts such as potassium bicarbonate and potassium citrate have been shown to reduce 24-hr urinary net acid excretion (NAE) in healthy adults. This approach requires taking many capsules daily, in split doses after each meal with a full glass of water. An alternative and perhaps more acceptable approach to achieving acid-base balance for most adults may be to modify their diet by increasing intake of alkali-producing foods, such as fruit. Maintaining acid base balance may be important for preserving bone and muscle and renal function and other outcomes but this has not been established. The investigators propose to determine whether adults who are provided with 100 g per day of a selection of dried fruits will actually consume enough of it to correct their acid-producing diets, as evidenced by a lowering of their urinary NAE. The investigators will also determine whether and how participants will alter their overall diets or their body weight when provided with the dried fruit. The comparator group will receive no dried fruit (or other intervention).

• Study Type: Interventional
• Enrollment (Actual): 109
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02111
      • Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• usual self-reported fruit intake not greater than 2.5 servings per day
• adequate dentition to chew dried fruit
• willing to avoid potassium supplements during the study
• willing to avoid antacids other than Pepto Bismol during the study

Exclusion Criteria:

Conditions

• diabetes or fasting plasma glucose on screening >125 mg/dl
• untreated thyroid disease
• untreated parathyroid disease
• cirrhosis
• unstable heart disease
• osteoporosis of the spine or hip
• alcohol use > 2 drinks per day
• chronic diarrheal syndrome
• estimated glomerular filtration rate < 50 ml/min
• serum potassium >5.3 meq/L
• abnormal serum calcium
• dysphasia
• malabsorption
• inflammatory bowel disease
• celiac disease
• chronic constipation
• gastric bypass surgery
• non-English speaking Medications
• potassium sparing diuretics
• oral glucocorticoids
• immunosuppressant drugs
• anabolic steroids in last 6 months
• estrogen in last 6 months
• osteoporosis treatment in the last 12 months with teriparatide abaloparatide calcitonin raloxifene denosumab
• osteoporosis treatment with a bisphosphonate in the last 2 years
• regular use of antacids > 3 times per week
• regular use of laxatives > 3 times per week
• any medication taken to alter appetite

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: dried fruit; 100 g per day of dried fruit	Other: food - dried fruit; raisins, apricots, figs, and pineapple
No Intervention: no dried fruit; no intervention to be given

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
change in 24-hour urinary NAE	NAE reflects net acid-base balance	12 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
rate of adherence with dried fruit	weight of dispensed fruit consumed, calculated as weight of fruit dispensed minus the weight of fruit returned	12 months
change in 24-hour urinary N-telopeptide	a measure of bone resorption	12 months
change in fat to lean tissue mass ratio	a measure of change in body composition by dual-energy x-ray absorptiometry (DXA:)	12 months
change in bone mineral density at the total body	measured by DXA	12 months
change in body weight	measured on a standard scale	12 months
change in grip strength	hand grip strength in kilograms assessed by a hand held dynamometer	12 months
Mediterranean diet score	a 14-item scale of adherence to a healthy Mediterranean style diet; a higher score represents a better diet	12 months
change in bone mineral density of the spine	measured by DXA	12 months
change in bone mineral density of the hip	measured by DXA	12 months
Health Aging and Body Composition-leg strength	defined as ability to do 5 repeated chair stands; assessed on a 4-point scale; a higher score represents a better performance	12 months
Health Aging and Body Composition - standing balance	defined as ability to stand in tandem position measured on a 4-point scale; a higher score represents a better performance	12 months
Health Aging and Body Composition- gait speed	defined as usual gait speed of performing a 6-meter walk; assessed on a 4-point scale; a higher score represents a better performance	12 months
Health Aging and Body Composition-physical performance battery	The total score is 12 points, representing the sum of the 4-point scores of the 3 domains (strength, balance and gait speed). A higher score represents a better performance.	12 months

Collaborators and Investigators

• Sponsor: Tufts University
• Collaborators: Tufts Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): August 27, 2018
• Primary Completion (Actual): March 17, 2020
• Study Completion (Actual): March 17, 2020

Study Registration Dates

• First Submitted: July 18, 2019
• First Submitted That Met QC Criteria: July 22, 2019
• First Posted (Actual): July 23, 2019

Study Record Updates

• Last Update Posted (Actual): October 29, 2020
• Last Update Submitted That Met QC Criteria: October 27, 2020
• Last Verified: October 1, 2020

More Information

Terms related to this study

• Other Study ID Numbers: 2980

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No