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Quality of Systematic Reviews of the Foods with Function Claims in Japan: Comparative Before- and After-Evaluation of Verification Reports by the Consumer Affairs Agency

Faculty of Regional Environment Science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
Tokyo Ariake Medical and Health Sciences University, 2-9-1 Ariake, Kouto-ku, Tokyo 135-0063, Japan
Division of Biostatistics and Clinical Epidemiology, University of Toyama School of Medicine, 2630 Sugiya, Toyama City, Toyama 930-0194, Japan
Faculty of Food and Nutritional Sciences, Toyo University, 1-1-1 Izumino, Itakura Town, Gunma 374-0193, Japan
Physical Education and Medicine Research Center Unnan, 328 Uji, Unnan City, Shimane 699-1105, Japan
Department of Nutrition, Faculty of Health Care, Kiryu University, 606-7 Asami, Midori City, Gunma 379-2329, Japan
Department of Food and Nutrition, Faculty of Human Life, Jumonji University, 2-1-28 Sugasawa, Niiza City, Saitama 352-8510, Japan
Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Aramachi, Nishitokyo City, Tokyo 202-8585, Japan
Author to whom correspondence should be addressed.
Nutrients 2019, 11(7), 1583;
Received: 27 May 2019 / Revised: 29 June 2019 / Accepted: 10 July 2019 / Published: 12 July 2019
PDF [702 KB, uploaded 18 July 2019]
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Background: In Japan, a new type of foods with health claims, called Foods with Function Claims (FFC), was introduced in April 2015 in order to make more products available that are clearly labeled with certain health functions. Regarding substantiating product effectiveness, scientific evidence for the proposed function claims must be explained by systematic reviews (SRs), but the quality of SRs was not clear. The objectives of this review were to assess the quality of SRs based on the FFC registered on the Consumer Affairs Agency (CAA) website in Japan, and to determine whether the CAA’s verification report in 2016 was associated with improvement in the quality of SRs. Methods: We evaluated the reporting quality of each SR by the AMSTAR checklist on methodological quality. We searched the database from 1 April to 31 October 2015 as the before-SR and from 1 July 2017 to 31 January 2018 as the after-SR. Results: Among the 104 SRs reviewed, 96 final products were included: 51 (53.1%) were supplements, 42 (43.8%) were processed foods without supplements, and 3 (3.1%) were fresh foods. Of the 104 SRs, 92 (88.5%) were qualitative reviews (i.e., without meta-analysis) and 12 (11.5%) performed a meta-analysis. The average quality score of before-SRs and after-SRs was 6.2 ± 1.8 and 5.0 ± 1.9, respectively, a statistically significant decrease (p < 0.001). Conclusion: Overall, the methodology and reporting quality of after-SRs based on the FFC were poorer than those of before-SRs. In particular, there were very poor descriptions and/or implementations of study selection and data extraction, search strategy, evaluation methods for risk of bias, assessment of publication bias, and formulating conclusions based on methodological rigor and scientific quality of the included studies. View Full-Text
Keywords: quality; systematic review; health claim; supplement quality; systematic review; health claim; supplement

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Kamioka, H.; Tsutani, K.; Origasa, H.; Yoshizaki, T.; Kitayuguchi, J.; Shimada, M.; Wada, Y.; Takano-Ohmuro, H. Quality of Systematic Reviews of the Foods with Function Claims in Japan: Comparative Before- and After-Evaluation of Verification Reports by the Consumer Affairs Agency. Nutrients 2019, 11, 1583.

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