Reconstruction of human food habits in early-modern Japan by isotope analysis of hairs embedded in the old books

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K21656
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 3:History, archaeology, museology, and related fields
• Research Institution: Ryukoku University
• Principal Investigator: MARUYAMA Atsushi 龍谷大学, 先端理工学部, 教授 (70368033)
• Co-Investigator(Kenkyū-buntansha): 入口 敦志 国文学研究資料館, 研究部, 教授 (80243872) ; 神松 幸弘 立命館大学, 立命館グローバル・イノベーション研究機構, 准教授 (20370140)
• Project Period (FY): 2019-06-28 – 2023-03-31
• Keywords: 江戸時代 / 同位体分析 / 毛髪 / 和装本 / PIXE分析 / 文化財建造物

Outline of Final Research Achievements

Hair embedded in 253 Japanese-style book-sets printed in the early modern and modern periods was extracted and subjected to carbon and nitrogen stable isotope analysis for dietary analysis and PIXE analysis to determine trace element content. Hair from modern humans (men and women of all ages) collected by an ethically-approved method was also subjected to PIXE analysis as a comparison (isotope ratios were not analyzed because they were known).
In an attempt to separate changes in diet and agriculture, we also began collecting samples to estimate chemical changes in rice, which has been the staple food of Japanese people. In particular, rice leaf samples estimated to have been harvested in the Kyoto area from the early modern period to the present day have already been collected sufficiently from cultural property buildings and are expected to serve as material for testing the competing hypotheses arising from the hair analysis.

Free Research Field

同位体生態学

Academic Significance and Societal Importance of the Research Achievements

本研究活動で得られた知見は、当初計画以上に学際的である。すなわち、窒素同位体比は江戸時代を通じた海への依存度の上昇、炭素同位体比はC4植物への 依存度の上昇を明らかにしたほか、PIXE分析で定量される多種の微少元素含有量は、江戸時代よりも現代において小さいことが示された。歴史学や自然人類学は もとより、栄養学や土壌学にも刺激しうる知見が見いだされつつある。さらに刺激的な生物試料（イネ）の入手に目途がついたことの学術的将来性も強調したい。