a1 Department of Social and Preventive Epidemiology, School of Public Health, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
a2 Department of Health and Nutrition, School of Home Economics, Wayo Women's University, Chiba, Japan
a3 Laboratory of Physiological Nutrition, Kagawa Nutrition University, Saitama, Japan
Previous studies on the relationship of local food environment with residents' diets have relied exclusively on self-reported information on diet, producing inconsistent results. Evaluation of dietary intake using biomarkers may obviate the biases inherent to the use of self-reported dietary information. This cross-sectional study examined the association between neighbourhood food store availability and 24 h urinary Na and K excretion. The subjects were 904 female Japanese dietetic students aged 18–22 years. Neighbourhood food store availability was defined as the number of food stores within a 0·5-mile (0·8-km) radius of residence. Urinary Na and K excretion and the ratio of urinary Na to K were estimated from a single 24 h urine sample. After adjustment for potential confounding factors, neighbourhood availability of confectionery stores/bakeries was inversely associated with urinary K, and was positively associated with the ratio of Na to K (P for trend = 0·008 and 0·03, respectively). Neighbourhood availability of rice stores showed an independent inverse association with urinary K (P for trend = 0·03), whereas neighbourhood availability of supermarkets/grocery stores conversely showed an independent positive association with this variable (P for trend = 0·03). Furthermore, neighbourhood availability of fruit/vegetable stores showed an independent inverse association with the ratio of Na to K (P for trend = 0·049). In a group of young Japanese women, increasing neighbourhood availability of supermarkets/grocery stores and fruit/vegetable stores and decreasing availability of confectionery stores/bakeries and rice stores were associated with favourable profiles of 24 h urinary K (and Na) excretion.
(Received December 09 2009)
(Revised March 02 2010)
(Accepted March 30 2010)
(Online publication April 27 2010)
† Other members of the Japan Dietetic Students' Study for Nutrition and Biomarkers Group are as follows: Mitsuyo Yamasaki, Yuko Hisatomi, Junko Soezima, and Kazumi Takedomi (Nishikyushu University); Toshiyuki Kohri and Naoko Kaba (Kinki University); Etsuko Uneoka (Otemae College of Nutrition); Hitomi Hayabuchi and Yoko Umeki (Fukuoka Women's University); Keiko Baba and Maiko Suzuki (Mie Chukyo University Junior College); Reiko Watanabe and Kanako Muramatsu (University of Niigata Prefecture); Kazuko Ohki, Seigo Shiga, Hidemichi Ebisawa, and Masako Fuwa (Showa Women's University); Tomoko Watanabe, Ayuho Suzuki, and Fumiyo Kudo (Chiba Prefectural University of Health Science); Katsumi Shibata, Tsutomu Fukuwatari, and Junko Hirose (The University of Shiga Prefecture); Toru Takahashi and Masako Kato (Mimasaka University); Toshinao Goda and Yoko Ichikawa (University of Shizuoka); Junko Suzuki, Yoko Niida, Satomi Morohashi, Chiaki Shimizu, and Naomi Takeuchi (Hokkaido Bunkyo University); Jun Oka and Tomoko Ide (Tokyo Kasei University); and Yoshiko Sugiyama and Mika Furuki (Minamikyushu University).