2021 年 77 巻 10 号 p. 258-265
Chicken eggshell membrane (ESM) is a two-layered insoluble sheet located between the eggshell and the albumen and is composed of fibrous proteins. Naturally occurring composite material, such as ESM have various ameliorative effects for osteoarthritis of the knee, joint, and connective tissue when ingested and absorbed as supplements. The physiological effects by oral ESM intake, especially on respiratory function,remain unclear. We have recently reported that tritium-labeled ESM powder can be digested and absorbed by mice and distributed in tissues throughout the body. We have also reported that the application of hydrolyzed water-soluble ESM to human skin significantly improved skin elasticity, which declines with aging, in a before and after comparison at 3 months, and significantly reduced wrinkles at the corners of the eyes compared to controls. In the present double-blind, placebo-controlled study, we examined breathing, skin, and body functions, such as zigzag walking, after ESM ingestion compared to controls. We hypothesized this to improve physical functions by improving the extracellular matrix (ECM) within the range of homeostasis. Among 20 healthy subjects (age: 21–68 years), the group given ESM supplementation for 8 weeks showed significantly increased rate of change in arm skin elasticity, respiratory function (forced expiratory volume in 1 s to forced vital capacity ratio (FEV1/FVC)), and zigzag walking speed compared to controls. There was a significant correlation between the rate of change in FEV1/FVC and that of zigzag walking after 8 weeks compared to the initial values. These functional improvements observed in skin elasticity, lung function, and motor function with oral intake of ESM suggest that maintaining elasticity in the cellular environment can support overall health and activity levels.