Maturitas 69 (2011) 268–272 Contents lists available at ScienceDirect Maturitas jo ur n al hom ep age : www.elsevier.com/locate/maturitas Legumes and soy products consumption and functional disability in older women Jinhee Kim a,b , Yunhwan Lee a,b,∗ , Soon Young Lee a,b a Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Republic of Korea b Institute on Aging, Ajou University Medical Center, Suwon, Republic of Korea a r t i c l e i n f o Article history: Received 8 December 2010 Received in revised form 3 March 2011 Accepted 30 March 2011 Keywords: Aged Legumes Soy foods Disability Diet Women a b s t r a c t Objectives: This study was to examine the association between frequency of legumes and soy products consumption and functional disability in older Korean women. Study design: Cross-sectional study. Data came from the 2005 Korea National Health and Nutrition Exam- ination Survey (KNHANES). Subjects were 562 women aged 65 years and older living in the community. Main outcome measures: Frequency of legume consumption was obtained by using food frequency ques- tionnaire and functional disability was assessed using the instrumental activities of daily living (IADL) and ADL scales. Poisson regression analyses were conducted to examine the association of frequency of legume and soy consumption with functional disability, controlling for covariates. Results: Dietary intake of legumes and soy products was associated with a significantly reduced risk of IADL disability after controlling for potential risk factors (p = 0.002 for trend). Compared with women who consumed legumes and soy products <1 time per week, those who consumed ≥3 times per day had a reduced risk of IADL disability (prevalence ratio = 0.70; 95% confidence interval: 0.51–0.96). In contrast, legumes and soy products consumption was not significantly associated with ADL disability. Conclusions: Frequent legumes and soy products consumption was inversely associated with IADL dis- ability in older women. Further studies are needed to clarify the protective effect of legume consumption on functional disability in older people. © 2011 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Functional disability is a major public health concern with rapid aging of the population [1]. In Korea, 46.0% and 17.8% of the elderly population have instrumental activities of daily living (IADL) and activities of daily living (ADL) disability, respectively [2]. Women tend to be more disabled than men, with the prevalence rate in women being about two times higher than that of men. Age-related loss in skeletal muscle mass may contribute to the high physical disability rate in older adults [3–6]. Elderly women exhibit higher strength-related functional limitations than men because of a smaller reserve capacity [7]. Moreover, estrogen levels steeply decline in menopause and are considered to play an impor- tant role in increasing the risk for functional disability dependent on muscle loss [8]. Traditionally, Koreans consume legumes and soy products on a daily basis [2]. Legumes are rich in protein, dietary fiber, and a variety of micronutrients and phytochemicals [9]. Soy foods are distinctive among the legumes because they serve as a concen- ∗ Corresponding author at: Department of Preventive Medicine and Public Health, Ajou University School of Medicine, San 5, Wonchun-dong, Youngtong-gu, Suwon 443-721, Republic of Korea. Tel.: +82 31 219 5085; fax: +82 31 219 5084. E-mail address: yhlee@ajou.ac.kr (Y. Lee). trated source of isoflavones [9]. Isoflavones have weak estrogenic properties because of their structural similarity to 17-estradiol [10,11]. Accumulating evidence suggests beneficial influence of soy isoflavones on metabolic and gynecologic conditions in women [12–14]. Recent studies in postmenopausal women, further, indi- cate protective effects of isoflavones on lean tissue [15] and fat-free mass [16]. As far as we are aware, however, no investigators have reported observations on the association of legumes and soy foods con- sumption with physical disability in a representative community sample of older women. The aim of this study is to examine the association of the frequency of legumes and soy products con- sumption with functional disability in older Korean women, using population-based national survey data. 2. Methods 2.1. Study population Data were from the 2005 Korea National Health and Nutri- tion Examination Survey (KNHANES). Detailed information of the survey is described elsewhere [2]. Briefly, KNHANES is a nation- wide representative study using a stratified, multistage probability sampling design for the selection of household units. The sur- 0378-5122/$ – see front matter © 2011 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.maturitas.2011.03.021