[Effect of variation of lemon intake and walking in daily life on various indicators of muscle mass and blood biochemistry in menopausal middle-aged and elderly women].

OBJECTIVES We examined the factors considered to change body composition and blood biochemistry indicators in menopausal middle-aged and elderly women. These changes result from exercise by walking as part of their daily activities and lemon consumption by women who live on the small islands of the Seto Inland Sea, Japan's largest citrus fruit (lemon)-producing region. METHODS Between September 2011 and March 2012, we recorded the daily lemon consumption and the number of steps taken by 101 middle-aged and elderly female lemon farmers. We also measured their body dimensions, body compositions, and blood pressure pulse wave velocity and conducted blood tests before and after the survey period. The results before and after the survey period were compared by the t-test and associations were determined on the basis of Pearson's correlation coefficient. Covariance structural analysis was carried out to determine causal associations. RESULTS From the results of covariance structure analysis, lemon intake did not have a direct impact on each item examined. The third item, i.e., "the factors related to arteriosclerosis," was affected indirectly via citric acid and fatigue, and anticoagulation was shown. The fourth item, i.e., "the factors related to maintenance of muscle mass," which is affected by menopausal years and the change in walking speed, was shown to be associated with the second item, i.e., "the factors related to lipid metabolism." Menopausal years affected the first, third and fourth items. CONCLUSIONS Lemon intake did not have a direct impact on each item. Lemon has been shown to indirectly affect the third item through citric acid. Walking affected the second item, the level of total cholesterol, such as HDL cholesterol, through the fourth item. The importance of providing services that lead to sustained physical activity and a well-balanced metabolism between lipids and carbohydrates has been shown.