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Effect of soy protein containing isoflavones on cognitive function, bone mineral density, and plasma lipids in postmenopausal women: a randomized controlled trial
Kreijkamp-Kaspers S, Kok L, Grobbee DE, de Haan EH, Aleman A, Lampe JW, van der Schouw YT.. JAMA, 2004-07-01
Topic: Gut, metabolism and diet
Context Postmenopausal estrogen therapy has been posited to have some beneficial effects on aging processes, but its use has risks. Isoflavones, estrogenlike compounds naturally occurring in plant foods, might confer positive effects with fewer adverse effects. Objective To investigate whether soy protein with isoflavones improves cognitive function, bone mineral density, and plasma lipids in postmenopausal women. Design, setting, and participants Double-blind, randomized, placebo-controlled trial of 202 healthy postmenopausal women aged 60 to 75 years, recruited from a population-based sample in the Netherlands, conducted between April 2000 and September 2001. Intervention Participants were randomly assigned to receive 25.6 g of soy protein containing 99 mg of isoflavones (52 mg genistein, 41 mg daidzein, and 6 mg glycetein or total milk protein as a powder on a daily basis for 12 months. Main outcome measures Cognitive function was assessed using the following instruments: dementia, Mini-Mental State Examination; memory, Rey Auditory Verbal Learning Test, immediate recall, delayed recall, and recognition, the Digit Span forward and reversed, and the Doors test; complex attention tasks, Digit Symbol Substitution and Trailmaking, A1, A2, and B; and verbal skills, Verbal Fluency A and N, animals and occupations, and the Boston Naming Task. Bone mineral density of the hip and lumbar spine was assessed using dual-energy x-ray absorptiometry scanning. Lipid assessment included lipoprotein(a), total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides. Results A total of 175 women completed the baseline and at least 1 postintervention analysis and were included in the modified intent-to-treat analysis. Adherence was good (median plasma genistein levels, 17.2 and 615.1 nmol/L for placebo and soy group, respectively). Cognitive function, bone mineral density, or plasma lipids did not differ significantly between the groups after a year. Conclusion This double-blind randomized trial does not support the hypothesis that the use of soy protein supplement containing isoflavones improves cognitive function, bone mineral density, or plasma lipids in healthy postmenopausal women when started at the age of 60 years or later.
Key findings
- Results A total of 175 women completed the baseline and at least 1 postintervention analysis and were included in the modified intent-to-treat analysis.
- Cognitive function, bone mineral density, or plasma lipids did not differ significantly between the groups after a year.
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Study details
- Study designrandomized controlled trial
- Participants175
- Evidence strengthHigh
How this study scored 79/100
Published in a top-tier journal, and it is a randomised controlled trial. Scored zero for effect reported because the record does not state it. We have no data on journal's citation record, times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record and multi-centre collaboration, so those were left out: it earned 46 of the 58 points we could judge it on, which is 79 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 10 / 10 | Tier 1 — top-tier general journal (JAMA) |
| Journal's citation record | — / 4 | No journal record from OpenAlex — left out of this score |
| Study design | 11 / 12 | A randomised controlled trial |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2004 — older than 20 years, still counted |
| Sample size | 2 / 4 | 175 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 2 / 2 | Randomised and blinded or placebo-controlled (as stated in the record) |
| Times cited | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 15238592) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 46 / 58 | Scored on 11 of 20 parts. We have no data for the rest, so they are left out: 46 of the 58 points we could judge it on is 79 out of 100. |
| Total | 79 / 100 | — |
What each of these 20 components measures, and what this score is not →
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record names 7 authors; APA and Vancouver show the first six, BibTeX and the downloads carry all of them. Check the citation against the original before you use it.
APA 7th
Kreijkamp-Kaspers, S., Kok, L., Grobbee, D. E., de Haan, E. H., Aleman, A., Lampe, J. W., et al. (2004). Effect of soy protein containing isoflavones on cognitive function, bone mineral density, and plasma lipids in postmenopausal women: a randomized controlled trial. JAMA. https://doi.org/10.1001/jama.292.1.65
Vancouver
Kreijkamp-Kaspers S, Kok L, Grobbee DE, de Haan EH, Aleman A, Lampe JW, et al. Effect of soy protein containing isoflavones on cognitive function, bone mineral density, and plasma lipids in postmenopausal women: a randomized controlled trial. JAMA. 2004. doi:10.1001/jama.292.1.65. PMID: 15238592.
BibTeX
@article{kreijkampkaspers2004-15238592,
author = {Kreijkamp-Kaspers, S. and Kok, L. and Grobbee, D. E. and de Haan, E. H. and Aleman, A. and Lampe, J. W. and van der Schouw, Y. T.},
title = {{Effect of soy protein containing isoflavones on cognitive function, bone mineral density, and plasma lipids in postmenopausal women: a randomized controlled trial}},
journal = {JAMA},
year = {2004},
doi = {10.1001/jama.292.1.65},
pmid = {15238592},
url = {https://doi.org/10.1001/jama.292.1.65}
}
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