# Impact of protein and alkali supplementation on skeletal muscle in older adults

> **NIH NIH R01** · TUFTS UNIVERSITY BOSTON · 2021 · $381,424

## Abstract

PROJECT SUMMARY
Skeletal muscle loss and impairment – prominent features of the aging process – lead to physical disability.
There is plausible evidence that altering components of the diet, mainly protein intake and acid/base balance,
may improve indices of muscle health in older adults and thus translate to a reduction in physical disability. A
growing number of studies suggest that increasing protein intake using a whey protein supplement may benefit
muscle health in older adults. However, a main concern is that high protein results in a large dietary acid load
from the breakdown of protein to acidogenic byproducts, which could in turn promote muscle degradation
particularly in older adults with age-related declines in renal excretion of acid. Thus, our hypothesis is that the
balance between the amount of protein in the diet (anabolic component) and the net acid load of the diet
(catabolic component) in part determines whether the diet as a whole has a net anabolic or catabolic effect on
muscle. Preliminary data from our group have suggested that a daily potassium bicarbonate (KHCO3)
supplement improved lower extremity muscle power in postmenopausal women. Based on our preliminary data,
we plan to conduct a randomized, double-blind, placebo-controlled, 2x2 factorial study in which sedentary men
and women age 65 and older on baseline lower protein diets will be enrolled. Participants will assigned to one
of four groups: either a whey protein supplement (to raise protein intake to 1.5 g/kg/d) with or without KHCO3
81 mmol/d or an isocaloric placebo supplement with or without KHCO3 81 mmol/d for 24 wks. The primary
outcome is lower extremity muscle power. Secondary outcomes are lower extremity muscle endurance,
physical performance, lean mass, and 24-hr urinary nitrogen excretion. Twenty-four-week changes in these
outcomes will be compared in the 4 groups. Our central hypothesis is that higher protein intake plus a
neutralizing alkaline salt will have additive effects on muscle performance and mass in older adults to either
intervention alone. If successful, this research could result in a paradigm shift in dietary advice to older adults
to reduce physical disability. As 1 in 5 US adults will be over age 65 by year 2040, a safe dietary intervention
that reduces age-related musculoskeletal decline will be an important preventative health step for our aging
society.

## Key facts

- **NIH application ID:** 9939356
- **Project number:** 5R01AG055443-03
- **Recipient organization:** TUFTS UNIVERSITY BOSTON
- **Principal Investigator:** Lisa Ceglia
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $381,424
- **Award type:** 5
- **Project period:** 2018-09-30 → 2025-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9939356

## Citation

> US National Institutes of Health, RePORTER application 9939356, Impact of protein and alkali supplementation on skeletal muscle in older adults (5R01AG055443-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9939356. Licensed CC0.

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