Dietary α‐Linolenic Acid (ALA) is Sufficiently Converted to Docosahexaenoic Acid (DHA) to Increase Bioactive Lipids Derived from DHA
Notice bibliographique
Résumé
Background There is considerable debate on whether α‐linolenic acid (ALA) can be sufficiently converted to docosahexaenoic acid (DHA) for optimal health. DHA has beneficial health effects and is critical for tissues such as the retina and brain. It produces bioactive lipids, such as resolvins, protectins and hydroxy DHA (HDoHE) with anti‐inflammatory, vasodilatory, anti‐aggregatory and anti‐proliferative effects. Many organizations worldwide provide recommendations for minimal DHA intake, but vegans, who consume little or no DHA, have shown no apparent detrimental health effects. Moreover, the Institute of Medicine Dietary Reference Intakes do not provide a minimum recommendation for DHA, and only have a recommendation for adequate ALA intake. Although dietary ALA generally does not significantly alter DHA levels, tissue fatty acid levels are not always an accurate indication of bioactive lipid levels. Therefore, the objective of this study was to determine whether dietary ALA can alter levels of DHA derived bioactive lipids (oxylipins) in normal rat tissues. Methods Weanling Sprague‐Dawley rats were provided diets based on the AIN93G diet. The isocaloric and isolipidic diets had oils (soy, olive, flax) containing adequate levels of ALA (0.3 g/100 g diet) or higher ALA (3.4 g/100 g diet), with ALA replacing monounsaturated fatty acids in the latter diet. Male and female rats were provided the diets ad libitum for 6 weeks, after which livers, kidneys and serum were collected for oxylipin analysis. Phospholipid fatty acids were purified from lipid extracts using TLC and quantified as fatty acid methyl esters by GLC. Oxylipins were extracted in methanolic solutions containing deuterated internal standards. After solid phase extraction, lipidomic analysis of >150 oxylipins was performed by HPLC/MS/MS, and those above the limit of quantification (LOQ) were quantified using the stable isotope dilution method. Approximately 100 oxylipins above the LOQ were detected in each of the 3 tissues. Results Consistent with many prior studies, providing a higher ALA diet resulted in higher phospholipid ALA and eicosapentaenoic acid (EPA) in all 3 tissues, and DHA concentrations were only higher in liver, but not in the kidney or serum. Providing higher dietary ALA also resulted in higher levels of all ALA derived oxylipins detected, and most of the EPA derived oxylipins in all 3 tissues. With respect to DHA oxylipins, however, despite not altering DHA levels, in the kidney 12 DHA oxylipins were (~20–100%) higher in rats provided high ALA. Similarly in serum, 9 DHA oxylipins were (~20–100%) higher in rats provided high ALA. In liver, despite differences in DHA, only 2 oxylipins derived from this fatty acid were altered by dietary ALA level. Conclusions These results illustrate that although dietary ALA may not alter tissue DHA concentrations, it does increase the levels of many oxylipins derived from DHA in kidney and serum. This indicates that the conversion from ALA to DHA is sufficient to increase production of DHA derived bioactive lipids in these tissues. These findings may have implications for dietary recommendations of n‐3 fatty acids. Support or Funding Information Natural Sciences and Engineering Research Council of Canada (NSERC)
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».