Carbon labelling: what the evidence base looks like

What this literature is made of

This is a thin evidence base. It is included because the question gets asked, not because the literature has settled it — and a page that pretended otherwise would be worse than one that says so.

The distinction that matters most is between synthesis and primary research. A meta-analysis pools trials and is the closest thing to a settled answer a field produces. A narrative review is one group's reading of the same material and can be selective without being dishonest. Counting them together, which most citation counts do, obscures exactly the thing you want to know.

How this page is built

Everything above is computed from the citations this site harvested from PubMed and Crossref, not written by hand. When the weekly harvest finds a new paper on this topic, these counts change and the characterisation changes with them. That is the point: a hand-written claim about how strong an evidence base is starts decaying the day it is written.

Publication type is taken as the source records it. That is imperfect — journals label inconsistently, and a paper indexed as a "review" may be a systematic one — so treat the bands as approximate. They are accurate enough to distinguish a trial literature from a commentary literature, which is the distinction that matters.

The strongest work on this topic

Ordered by study design first, then recency. The full set is listed in the references below.

1. Splanchnic utilization of enteral alanine in humans90229-9) — Battezzati A, Haisch M, Brillon DJ et al., 1999, randomised controlled trial
2. Effect of lactic acid isomers on keratinocyte ceramide synthesis, stratum corneum lipid levels and stratum corneum barrier function — Rawlings AV, Davies A, Carlomusto M et al., 1996, randomised controlled trial
3. A bibliometric review on carbon accounting in social science during 1997-2020 — Zheng Y, Yu H, Zhang Y, 2022, review
4. Cardiovascular applications of hyperpolarized contrast media and metabolic tracers — Bhattacharya P, Ross BD, Bünger R, 2009, review
5. Methods for measuring gluconeogenesis in vivo — Previs SF, Brunengraber H, 1998, review