Aging is known as a risk factor for gait disorders, which lead to reduced quality of life. Gait disorders can potentially be a sign of a preclinical phase of neurological diseases. Therefore, routine monitoring of changes in ambulatory activity with age can lead to early detection of such disorders. JINS MEME is eyewear equipped with a triaxial accelerometer (mediolateral, anteroposterior, and vertical) and capable of measuring acceleration signals during gait. To validate effectiveness of JINS MEME in routinely monitoring age-related changes in ambulatory activity, the present study tested three hypotheses: (1) the frequency of mediolateral body sway during gait increases with age, (2) the variability of gait speed (anteroposterior) increases with age, and (3) the frequency of vertical body sway during gait increases with age. The present study included 118 subjects aged 25–69 years. The acceleration signals were measured by JINS MEME while each subject walked down a barrier-free 20-meter-long level corridor at a natural pace. Triaxial variances known for reflecting gait stability, were calculated from the acceleration signals during gait. An association between each of the triaxial variances and age was assessed by multiple linear robust regression analysis including sex as a nuisance covariate. We found significant positive correlations between the anteroposterior variance and age and between the vertical variance and age. The results supported our second and third hypotheses and raised an intriguing possibility that the triaxial accelerometer of JINS MEME is capable of detecting age-related changes in ambulatory activity.