Débat: quand prendre ses oméga 3? le matin ou le soir?

[Nutrimuscle-Conseils]

Dietary fish oil differentially ameliorates high-fructose diet-induced hepatic steatosis and hyperlipidemia in mice depending on time of feeding
Katsutaka Oishi The Journal of Nutritional Biochemistry Volume 52, February 2018, Pages 45-53

Chrononutrition is the science of nutrition based on chronobiology. Numerous epidemiological studies have shown that fish oil (FO) reduces the risk of cardiovascular events through various actions such as lowering triglycerides. The present study aimed to determine the time of day when the hypertriglyceridemia-decreasing ability of FO is optimal in mice. A high-fructose diet (HFrD) that induces hyperlipidemia in mice was replaced with the same diet containing 4% FO (HFrD-4% FO) at different times of the day for 2 weeks as described below. Mice were fed with HFrD alone (CTRL) or with HFrD containing 4% FO for 12 h around the time of activity onset [breakfast (BF)-FO] or offset [dinner (DN)-FO]. Plasma and liver concentrations of triglycerides and total cholesterol were reduced in BF-FO but not in DN-FO mice compared with CTRL mice. The temporal expression of genes associated with fatty acid synthesis such as Fasn, Acaca, Scd1 and Acly in the liver was significantly suppressed in both BF-FO and DN-FO mice. Expression levels of Scd1 in epididymal adipose tissue were significantly suppressed only in the BF-FO mice. Plasma concentrations of docosahexaenoic acid and eicosapentaenoic acid were far more increased in BF-FO than in DN-FO mice. Significantly more of these n-3 polyunsaturated fatty acids (PUFAs) were excreted in the feces of DN-FO than of BF-FO mice.

These findings suggest that dietary FO exerts more hypolipidemic activity at the time of breakfast than dinner because the intestinal absorption of n-3 PUFAs is more effective at that time.

[Nutrimuscle-Diététique]

L'huile de poisson alimentaire améliore différemment la stéatose hépatique et l'hyperlipidémie induites par le régime alimentaire à haute teneur en fructose chez la souris en fonction du moment de l'alimentation
Katsutaka Oishi The Journal of Nutritional Biochemistry Volume 52, février 2018, Pages 45-53

La chrononutrition est la science de la nutrition basée sur la chronobiologie. De nombreuses études épidémiologiques ont montré que l'huile de poisson (FO) réduit le risque d'événements cardiovasculaires grâce à diverses actions telles que la réduction des triglycérides. La présente étude visait à déterminer l'heure de la journée où la capacité de diminution de l'hypertriglycéridémie de FO est optimale chez la souris. Un régime riche en fructose (HFrD) qui induit une hyperlipidémie chez la souris a été remplacé par le même régime contenant 4% FO (HFrD-4% FO) à différents moments de la journée pendant 2 semaines comme décrit ci-dessous. Les souris ont été nourries avec HFrD seul (CTRL) ou avec HFrD contenant 4% FO pendant 12 h vers le début de l'activité [petit-déjeuner (BF) -FO] ou compensé [dîner (DN) -FO]. Les concentrations plasmatiques et hépatiques de triglycérides et de cholestérol total ont été réduites chez les souris BF-FO mais pas chez les souris DN-FO par rapport aux souris CTRL. L'expression temporelle des gènes associés à la synthèse des acides gras tels que Fasn, Acaca, Scd1 et Acly dans le foie a été significativement supprimée chez les souris BF-FO et DN-FO. Les niveaux d'expression de Scd1 dans le tissu adipeux épididymaire ont été significativement supprimés uniquement chez les souris BF-FO. Les concentrations plasmatiques d'acide docosahexaénoïque et d'acide eicosapentaénoïque étaient beaucoup plus élevées chez le BF-FO que chez la souris DN-FO. Beaucoup plus de ces acides gras polyinsaturés n-3 (AGPI) ont été excrétés dans les fèces de DN-FO que de souris BF-FO.

Ces résultats suggèrent que l'OP alimentaire exerce une activité hypolipidémique plus importante au moment du petit-déjeuner qu'au dîner, car l'absorption intestinale des AGPI n-3 est plus efficace à ce moment-là.

[Nutrimuscle-Conseils]

Diurnal rhythm of plasma EPA and DHA in healthy adults
Philippa A. Jackson Prostaglandins, Leukotrienes and Essential Fatty Acids January 16, 2020

Highlights
•Knowledge of the diurnal variation in circulating omega-3 polyunsaturated fatty acids may be an important consideration for the development of dosing protocols.
•A diurnal rhythm was detected for 20 out of the 21 plasma fatty acids that were analysed.
•Concentrations of DHA and EPA decreased in the overnight period, with the nadir for each estimated to occur at 05:43 and 08:41.
•The functional relevance of night time dosing of DHA and EPA is discussed.


Knowledge of the diurnal variation in circulating omega-3 polyunsaturated fatty acids (n-3 PUFAs) may be an important consideration for the development of dosing protocols designed to optimise tissue delivery of these fatty acids. The objective of the current study was to examine the variation in plasma concentrations of eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) over a 24-hour period in healthy adults under eating and sleeping conditions generally approximate to a free-living environment.

Twenty-one healthy participants aged 25 to 44 years took part in a single laboratory visit encompassing an overnight stay. EPA and DHA were measured in plasma samples collected every two hours from 22:00 until 22:00 the following day, with all meals being provided at conventional times. Cosinor analysis was used to estimate the diurnal variation in each fatty acid from pooled data across all participants. A significant diurnal variation in the pooled plasma concentrations of both fatty acids was detected. However, evidence of distinct rhythmicity was strongest for DHA. The timing of the peak concentration of DHA was 17:43 with a corresponding nadir at 05:43. In comparison, the observed acrophase for EPA was delayed by three hours, occurring at 20:41, with a nadir at 08:41.

This is the first time that the diurnal variation in these important bioactive fatty acids has been described in a sample of healthy adults following a normal pattern of eating and sleeping. In the absence of any dietary intake of EPA and DHA, circulating levels of these fatty acids fall during the overnight period and reach their lowest point in the morning. Consumption of n-3 PUFAs at night time, which counteracts this pattern, may have functional significance.