Effect of Dried Fruit Intake on Acid-base Balance

Study Overview
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Brief Summary
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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.

Detailed Description
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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).

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

Conditions
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Acid-Base Balance Disorder

Intervention / Treatment
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* Other: food - dried fruit


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

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

What is the study measuring?
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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 |