Rina Kurasawa¹, Hiroyuki Hasegawa², Suguru Kurokawa^1,2, Koji Karasawa³, Toshiyuki Ochi³, Takahiro Kubota⁴ and Ryoji Hirota⁵*

¹Graduate School of Health Sciences, Matsumoto University, Nagano, Japan
²Faculty of Human Health Sciences, Matsumoto University, Nagano, Japan
³R&D Division, Ina Food Industry Co., Ltd., Nagano, Japan
⁴Department of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Medical and Life Sciences, Niigata, Japan
⁵Department of Hygiene, Kitasato University School of Medicine, Kanagawa, Japan

*Corresponding Author: Ryoji Hirota, Department of Hygiene, Kitasato University School of Medicine, Kanagawa, Japan.

Received: October 14, 2025; Published: November 10, 2025

Abstract

Background: Frailty and sarcopenia are major health issues among older women. Agaro-oligosaccharides (AGO), low-molecular-weight carbohydrates derived from agarose, exhibit anti-inflammatory and antioxidant activities that may support muscle maintenance.

Methods: In this 12-week randomized, double-blind, placebo-controlled trial, 23 community-dwelling older women (AGO n = 12; placebo n = 11) received AGO (500 mg/day) or placebo. Outcomes included 10-m walking speed, grip strength, 30-second chair-stand test (CS-30), timed up-and-go (TUG), and lower-limb circumferences.

Results: At week 6, the AGO group showed a greater increase in left-hand grip strength than placebo (Δ = +1.2 ± 1.5 kg vs −0.5 ± 1.4 kg; p = 0.020) and a greater increase in right calf circumference (Δ = +0.6 ± 1.3 cm vs −1.1 ± 1.3 cm; p = 0.008). In the pre-frail subgroup (frailty score ≥4; n = 9), left-hand grip strength improved significantly with AGO (Δ = +1.8 ± 1.8 kg; p = 0.049). Between-group differences were not significant at week 12, although directions of change remained favorable in the AGO group. No serious adverse events occurred.

Conclusions: AGO supplementation (500 mg/day) was well tolerated and associated with short-term improvements in muscle strength and calf circumference among older women, with signals stronger in pre-frail participants. Larger, longer trials are warranted to confirm durability and clinical relevance.

Keywords: Agaro-oligosaccharides; sarcopenia; frailty; older women; randomized controlled trial; muscle strength

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Citation

Citation: Ryoji Hirota., et al. “Effect of Agaro-Oligosaccharide Intake on Prevention of Muscle Strength Decline in Older Women: A Randomized Controlled Trial”.Acta Scientific Medical Sciences 9.12 (2025): 15-25.

Copyright

Copyright: © 2025 Ryoji Hirota., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.