A global carbon and nitrogen isotope perspective on modern and ancient human diet

Abstract

Stable carbon and nitrogen isotope analyses are widely used to infer diet and mobility in ancient and modern human populations, potentially providing a means to situate humans in global food webs. We collated 13,666 globally distributed analyses of ancient and modern human collagen and keratin samples. We converted all data to a common “Modern Diet Equivalent” reference frame to enable direct comparison among modern human diets, human diets prior to the advent of industrial agriculture, and the natural environment. This approach reveals a broad diet prior to industrialized agriculture and continued in modern subsistence populations, consistent with the human ability to consume opportunistically as extreme omnivores within complex natural food webs and across multiple trophic levels in every terrestrial and many marine ecosystems on the planet. In stark contrast, isotope dietary breadth across modern nonsubsistence populations has compressed by two-thirds as a result of the rise of industrialized agriculture and animal husbandry practices and the globalization of food distribution networks.

Towards a science of archaeoecology

“…Zooarchaeology by mass spectrometry (ZooMS) is enabling 'rapid taxonomic identification of large bone assemblages, cultural heritage objects, and other organic materials of animal origin' ( [46], see p. 1). Complementing these, the study of carbon, nitrogen, and other stable isotopes provides a wealth of information on migration, feeding habits, and other aspects of ecology that could only be explored inferentially before [33] (Figure 2). These and other approaches can be used to augment our understanding of past ecological networks in the form of, for example, food webs that include humans [40,47], human-mediated extinction cascade studies [48], and human-induced mutualistic networks.…”

“…For example, the archaeological record contains middens of trash deposited by humans in the past [29], which include fragments of animals and plants used by humans at different points in time, as elucidated by the practices of zooarchaeology and archaeobotany [30,31]. Middens and other intentionally deposited remains can be augmented by other forms of environmental and ecological reconstruction, including tree ring proxies for climate change [32], isotopic analyses of bones [33], and proteomics to understand past faunal composition [34]. The addition of methods for reconstructing past temperature [35], rainfall [6], flood episodes [36], and climatic shifts [37] via modern methods has enhanced understanding of the environmental context of past cultures.…”

Shifting Baselines to Thresholds: Reframing Exploitation in the Marine Environment

“…It is not always possible to access baseline trophic web species from past ecosystems, thereby limiting the power of trophic web analysis in the past. However, past dietary analysis using carbon and nitrogen signatures is an established and successful field in historical ecology and biomolecular archeology (Miller et al, 2020;Bird et al, 2021), as well as various other applications, including elucidating cultural thresholds in resource use (Lewis and Sealy, 2018;Nord and Billström, 2018;Miller et al, 2020) and geographic region of origin (Hobson, 1999;Lightfoot and O'Connell, 2016).…”

Astaxanthin Bioactivity Is Determined by Stereoisomer Composition and Extraction Method

“…Most animals cannot synthesize ASX, so they need to acquire it in their diet. ASX is an example of an important micronutrient that has been greatly reduced in animal and human diets by the industrialization of agriculture and food processing [ 6 ]. ASX is easily thermally denatured during extraction, and its high hydrophobicity makes it difficult to maintain high bioavailability.…”