Dietary conjugated linoleic acid (CLA) in the cis‐9, trans‐11 isoform reduces parathyroid hormone (PTH) in male, but not female rats
Bibliographic record
Abstract
Previously a mixture of CLA isoforms reduced PTH in male rats over 8 wk. The objective herein was to determine: which isoform caused the reduction in PTH; if the affect was sex specific; and if CLA‐induced reductions in PTH were transient. Male and female weanling rats (n=48) were randomized to a control diet or one made with 0.5% of the diet as cis‐9, trans‐11 CLA, 0.5% of the diet as trans‐10, cis‐12 CLA or these CLA in a mixture. Measurements made after 4, 8 and 16 wk were: body weight, bioactive PTH, ionized Ca, whole body and regional (lumbar spine, femur and tibia) bone mineral content (BMC) and density (BMD) using dual energy x‐ray absorptiometry. Using a factorial design (CLA isomers, age and sex plus interactions), a sex by cis‐9, trans‐11 CLA interaction was observed in that reduced PTH (139.5 ± 63.9 vs 95.8 ± 42.4 pg/ml, P=0.02) and reduced femur BMC (0.63 ± 0.22 vs 0.58 ± 0.18 g, P=0.03) occurred in males only. No other effects of cis‐9, trans‐11 CLA were observed. Regarding trans‐10, cis‐12 CLA, no interaction effects were observed, but a main effect was observed to reduce lumbar spine BMC (0.56 ± 0.17 vs 0.53 ± 0.16 g, P<0.01) and BMD (0.265 ± 0.044 vs 0.255 ± 0.044 g/cm 2 , P<0.01). In summary, the cis‐9, trans‐11 CLA isoform is responsible for reduced PTH and this effect is sex‐specific; this was true whether fed as a pure isomer or mixed with an equal amount of trans‐10, cis‐12 CLA. These results require confirmation in other animal models such as ovariectomized rats and also in humans to expand the understanding of dietary CLA in health. Funding: Dairy Farmers of Canada & NSERC.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".