Hindawi Publishing Corporation Journal of Environmental and Public Health Volume 2012, Article ID 849305, 6 pages doi:10.1155/2012/849305 Research Article Relationship between RBC Mercury Levels and Serum n3 Polyunsaturated Fatty Acid Concentrations among Japanese Men and Women Mayumi Tsuji,1 Tetsuo Ando,2 Takao Kitano,3 Junji Wakamiya,2 Chihaya Koriyama,2 and Suminori Akiba2 1 Department of Environmental Health, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyusyu 807-8555, Japan 2 Department of Epidemiology and Preventive Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan 3 Department of Public Health, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto City 860-8556, Japan Correspondence should be addressed to Mayumi Tsuji, tsuji@med.uoeh-u.ac.jp Received 20 July 2011; Revised 1 November 2011; Accepted 8 November 2011 Academic Editor: David Strogatz Copyright © 2012 Mayumi Tsuji et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Aims. To evaluate potential health risk and beneﬁts of ﬁsh consumption, the association of ﬁsh consumption with total mercury levels in red blood cells (RBCs) and serum eicosapentaenoic acid (EPA) concentrations was examined. Subjects and Methods. Study subjects were 269 Japanese (98 men and 171 women) living in a remote island of Kagoshima, and their blood was drawn in 1994. Results. Total mercury levels were related to weekly ﬁsh consumption among women (P = 0.035) but not among men (P = 0.643). However, serum EPA levels were not related to ﬁsh consumption in both women and men. In contrast, EPA levels in the high-density ipoprotein (HDL) fraction of the sera were signiﬁcantly related to ﬁsh consumption (P values for men and women were 0.014 and 0.073, resp.). Interestingly, mercury levels were related to serum EPA levels and EPA in the HDL fraction of the sera (P = 0.001) among women (P = 0.005) but not among men. Sex diﬀerences in ﬁsh species consumed may be an explanation for the observed sex diﬀerence. Conclusion. Those ﬁndings suggest that the health beneﬁt of ﬁsh consumption can be maximized by the careful selection of ﬁsh species consumed. 1. Introduction Fish consumption increases the intake of n3 series polyunsat- urated fatty acids (PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are reported to have health beneﬁts. For example, it has been reported that n3-PUFA may decrease blood pressure [1] and ischemic heart disease risk [2, 3]. On the other hand, ﬁsh consump- tion is associated with methyl mercury intake [4–6], which may cause adverse health eﬀects. However, the amount of methyl mercury intake through ﬁsh consumption is not nec- essarily proportional to n3-PUFA since methyl mercury con- centration in ﬁsh meat is higher in ﬁsh species high on the marine food chain while n3-PUFA concentration in ﬁsh meat is not related to it [7, 8]. This study examined the association of ﬁsh consumption with blood mercury and serum EPA levels in order to examine potential health risk and beneﬁts of ﬁsh consumption. 2. Materials and Methods In July of 1994, the nutrition interview survey for over sixties was conducted, which was a part of medical checkup for elderly people in K town of a southern prefecture in Kyusyu, Japan. We collected the information on the frequencies of consumption of various food items, including raw ﬁsh, ﬁsh paste products, and dry ﬁsh. During the health checkup, blood samples were also obtained from the subjects and separated into the serum elements and the red blood cells (RBC) by centrifugation