A randomized study on the effect of dried fruit on acid-base balance, diet quality, and markers of musculoskeletal health in community dwelling adults

Authors: CEGLIA, LISA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; SHEA, KYLA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; RASMUSSEN, HELEN - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; GILHOOLY, CHERYL - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; DAWSON-HUGHES, BESS - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: Journal of the American Nutrition Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/23/2022
Publication Date: 7/11/2022
Citation: Ceglia, L., Shea, K., Rasmussen, H., Gilhooly, C., Dawson-Hughes, B. 2022. A randomized study on the effect of dried fruit on acid-base balance, diet quality, and markers of musculoskeletal health in community dwelling adults. Journal of the American Nutrition Association. https://doi.org/10.1080/27697061.2022.2082599.
DOI: https://doi.org/10.1080/27697061.2022.2082599

Interpretive Summary: Older adults have a decreased ability to rid the body of excessive dietary acid, which can harm musculoskeletal health. This study tested whether adding up to 4 servings/day of dried fruit, a base-producing food, versus no added fruit for 6 months alters urinary net acid excretion - a measure of diet acid load. Changes in weight, measures of musculoskeletal health, and diet quality were also collected. Community-dwelling healthy older adults on self-reported low fruit diets were enrolled. Results revealed that added fruit had no significant impact on net acid excretion when compared to a no added fruit control. The absence of an effect may have been attributable to a high day-to-day variability in consumption of foods affecting net acid excretion in this field study of older adults consuming a self-selected diet. Added fruit also had no significant effect on weight, fat, muscle, or bone outcomes over a 6-month period.

Technical Abstract: Objectives We tested whether 100 g/day of dried fruit (vs. no supplemental fruit control) for 6 months alters 24-hr urinary net acid excretion (NAE), bone resorption, weight, body composition, muscle performance, and diet quality. We explored consistency of self-selected dietary composition and potential renal acid load (PRAL). Methods This randomized, single-blind, 2-armed study included 83 normal- and over-weight men and postmenopausal women (age >= 50 years) on self-reported low fruit diets. Endpoints included group differences in NAE (primary), 24-hr urinary N-telopeptide (NTX), weight, body composition, muscle performance, and diet quality. Results At baseline, mean (+/-SD) age was 69+/-8 years; 86% were Caucasian; body mass index was 24.5+/-2.8 kg/m2; 46% female, and NAE was 32.4+/-23.1 mmol with no significant baseline group differences. No significant group differences were noted in NAE (primary), NTX, weight, body composition, muscle performance or diet quality at 6 months. In the cohort as a whole, 6-month change in NAE was positively associated with change in NTX, but no significant associations were noted in other outcomes. PRAL on the day of the urine collection was positively associated with NAE. Comparison of two consecutive baseline 24-hr diet recalls revealed wide intra-individual variability in PRAL in self-selected diets in our participants. Conclusion In this field study of older adults consuming self-selected diets, making one change to the diet by adding 100 g/day of dried fruit (equivalent to 4 servings per day) had no significant impact on NAE when compared to a no supplemental fruit control. This null finding may be attributable to the high day-to-day variability in consumption of foods affecting NAE. Added fruit also had no significant effect on weight, fat, muscle, or bone outcomes over a 6-month period.