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Diet, inflammation and the gut microbiome: Mechanisms for obesity-associated cognitive impairment
Leigh SJ, Morris MJ.. Biochimica et biophysica acta. Molecular basis of disease, 2020-03-18
Topic: Risk, prevention and care in population studies
Poor diet and obesity are associated with cognitive impairment throughout adulthood, and increased dementia risk in aging. Here we review the current literature interrogating the mechanisms by which diets high in fat, or fat and sugar lead to cognitive impairment, focusing on changes to gut microbiome composition, inflammatory signalling and blood-brain barrier integrity. Preclinical studies indicate weight gain is not necessary for diet-induced cognitive impairment. Rather, gut microbiome composition, and systemic and central inflammatory processes appear to contribute to diet-induced cognitive impairment. While both obese humans and rodents exhibit reduced blood-brain barrier integrity, cognitive impairments precede these changes, suggesting other mechanisms may underly diet-induced cognitive changes. Other potential candidates include hormone, glucoregulatory and cardiovascular changes. Poor diet and obesity act through multiple mechanisms to affect cognitive health and the challenge for future research is to identify key processes that can be reversed to improve cognition and quality of life.
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APA 7th
Leigh, S. J., & Morris, M. J. (2020). Diet, inflammation and the gut microbiome: Mechanisms for obesity-associated cognitive impairment. Biochimica et biophysica acta. Molecular basis of disease. https://doi.org/10.1016/j.bbadis.2020.165767
Vancouver
Leigh SJ, Morris MJ. Diet, inflammation and the gut microbiome: Mechanisms for obesity-associated cognitive impairment. Biochimica et biophysica acta. Molecular basis of disease. 2020. doi:10.1016/j.bbadis.2020.165767. PMID: 32171891.
BibTeX
@article{leigh2020-32171891,
author = {Leigh, S. J. and Morris, M. J.},
title = {{Diet, inflammation and the gut microbiome: Mechanisms for obesity-associated cognitive impairment}},
journal = {Biochimica et biophysica acta. Molecular basis of disease},
year = {2020},
doi = {10.1016/j.bbadis.2020.165767},
pmid = {32171891},
url = {https://doi.org/10.1016/j.bbadis.2020.165767}
}
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Key findings
- Poor diet and obesity are associated with cognitive impairment throughout adulthood, and increased dementia risk in aging.
Why it matters
This review describes how diets high in fat, or fat and sugar, may lead to cognitive impairment through changes to gut microbiome composition, inflammatory signalling and blood-brain barrier integrity, with preclinical studies indicating weight gain is not necessary for this. It identifies mechanisms but does not show that any dietary change prevents or treats Alzheimer's disease.
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Study details
- Evidence strengthLow
How this study scored 46/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Biochimica et biophysica acta. Molecular basis of disease) |
| Journal's citation record | 2 / 4 | Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease: journal h-index 227 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 2 / 5 | 2020 — within 10 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 221 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 27.6 citations a year over 8 year(s) since 2020 |
| Impact for its field and year | 4 / 6 | Cited 8.2× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 5 other studies in this library |
| Still being cited | 3 / 4 | Cited 105 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Margaret J. Morris: h-index 67 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | UNSW Sydney: institution h-index 1,101 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 32171891) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 46 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1016/j.bbadis.2020.165767
- PubMed: 32171891
- Original source →
- Free full text: Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
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