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Introduction: Nutritional intake and dysregulation of fatty acid metabolism play a role in the progression of various tumors, but the consumption of fatty acids is difficult to assess accurately with dietary questionnaires. Biomarkers can objectively assess intake, storage and bioavailability., Objective: We studied the association between the polyunsaturated fatty acid (PUFA) composition of abdominal subcutaneous adipose tissue (good indicator of dietary intake over 2-3 years) and all-cause mortality., Methods: In the multicenter AGARIC study, samples from 203 patients with colorectal cancer (CRC) undergoing curative surgery, were harvested from subcutaneous adipose tissue, which were then analyzed for PUFA composition., Results: After a median follow-up of 45 months, 76 patients died. These patients were more often men (72.4% versus 57.5%, P = 0.04), diabetic (32.9% versus 13.4%, P = 0.001), old (median: 74.5 versus 66.6 years, P < 0.001) and with high alcohol consumption (47.4% versus 30.7%, P = 0.005). An increased risk of death was observed with higher levels of 20:2 ω-6 (hazard ratio tertile3 vstertile1 (HR T3vsT1 ) 2.12; 95% confidence interval (CI) 1.01-4.42; p-trend = 0.04), 22:4 ω-6 (HR T3vsT1 = 3.52; 95% CI = 1.51-8.17; p-trend = 0.005), and 22:5 ω-6 (HR T3vsT1 = 3.50; 95% CI = 1.56-7.87; p-trend = 0.002). Conversely, the risk of death seemed lower when higher concentrations of 18:3 ω-6 (HR T3vsT1 = 0.52; 95% CI = 0.27-0.99; p-trend = 0.04) and the essential fatty acid, α-linolenic acid 18:3 ω-3 (HR T3vsT1 = 0.47; 95% CI = 0.24-0.93; p-trend = 0.03) were observed., Conclusion: The risk of death was increased in CRC patients with higher concentrations of certain ω-6 PUFAs and lower concentrations of α-linolenic acid in their subcutaneous adipose tissue. These results reflect dietary habits and altered fatty acid metabolism. Our exploratory results warrant confirmation in larger studies with further exploration of the mechanisms involved., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Lipid emulsification is a technique that is being explored for improving the bioavailability of omega 3 (n-3) long chain (LC) fatty acid (FA). The nature of the emulsifiers can differently impact the lipid bioavailability via a modification of the lipolysis step. Among natural emulsifiers, gum acacia (GA), an indigestible polysaccharide, provides protective encapsulation of n-3 by forming a specifically crown-like shape around lipid drops, which could also impact the digestion step. Despite the interest in lipolysis rate, the impact of GA on lipid bioavailability has never been explored in a complete physiological context. Thus, we followed in a kinetics study the n-3 bioavailability in rat lymph, orally administered DHA-rich oil, formulated based on GA compared to the bulk phase form of the oil. The AUC values were significantly improved by +121% for total TG and by 321% for n-3 PUFA, specifically for EPA (+244%) and for DHA (+345%). Benefits of GA have also been related to the transport of FA in lymph, which was 2 h earlier (Tmax = 4 h), compared to the Tmax (6 h) obtained with the bulk phase oil. All the data showed that GA is one of the most favorable candidates of natural emulsifiers to improve n-3 bioavailability and their rate of absorption for health targets.

We investigated the impact of increased alpha-linolenic acid (ALA) dietary levels on its plasma bioavailability and its bioconversion in n -3 long chain poly unsaturated fatty acids during a 60-d kinetics and the oxidative stress potentially associated. Rats were submitted to a normolipidic diet providing 0, 3, 10 and 24% ALA of dietary lipids for 0, 15, 30 and 60 days. The lipid peroxidation and oxidative stress (nitric oxide (NO) contents and catalase (CAT), superoxide dismutase (SOD), gluthation peroxidase (GPx) activities) were studied in the liver and plasma. When the diet was deprived in n -3 PUFAs, ALA, (eicosanoic acid) EPA and docosahexaenoic acid (DHA) levels decreased in all lipid fractions of plasma and in red blood cell (RBC) lipids. The addition of ALA in the diet linearly improves its bioavailability and its bioconversion in EPA ( R ²=0.98). By providing 10 to 24% ALA in dietary lipids (LA/ALA, 1·6 and 5·5 respectively), ALA and EPA were more broadly packaged in all lipid fractions (triglyceride (TAG), cholesterol ester (CE) and free fatty acids (FFA)) of plasma from 15 to 30 days timeframe. Only 3% ALA was sufficient to promote the maximal bioconversion of ALA in DHA in phospholipid (PL) and TAG fractions. Additionally, the improvement of ALA bioconversion in EPA and DHA did not impact the oxidative stress markers and limiting lipid peroxidation. To conclude, this study demonstrated that in rat, 10% ALA in the lipid diet for 15-30 days promotes its bioavailability and its bioconversion and allowed the greatest levels in plasma and RBCs.

The aim of this work was to study the bioavailability of n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA), i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), carried by marine phospholipids (PL) and formulated in different supramolecular forms. Marine PL were administrated in rats either (1) in bulk form, or (2) as an oil-in-water emulsion, or (3) as liposomes. Each dietary formulation was characterized by a similar fatty acid (FA) profile and provided the same n-3 LC-PUFA amount. Intestinal bioavailability of n-3 LC-PUFA was monitored in the lymph compartment in a duct fistula model. On the one hand, the emulsification of plant oils with PL increased the overall intestinal absorption of dietary FA by 84% without affecting the lymph FA profile compared with the bulk form, suggesting that emulsification favoured the absorption of the total dietary FA derived from both triglycerides (TG) and PL. On the other hand, the liposome form did not modify the lymph lipid amount compared with the bulk form, but specifically increased the n-3 LC-PUFA levels. The dietary forms of PL influenced the position of some FA on the glycerol backbone of lymph TG and PL. In conclusion, using marine PL as an emulsifier promoted total FA absorption independently of the dietary lipid carrier (TG or PL) and the FA type. Structuring PL as liposomes specifically increased the intestinal bioavailability of FA esterifed in this lipid class, such as DHA, resulting in a higher incorporation into lymph lipids. Thus, using specific PL supramolecular forms would guide n-3 LC-PUFA towards total lipid absorption or specific FA absorption, according to the dietary needs.

The aim of this work was to study the bioavailability of fatty acids (FA), focusing on n-3 long-chain (LC) PUFA, carried by different molecular lipid species, that is, phospholipids (PL) or TAG, with three formulations based on fish oils or marine PL, providing a similar n-3 LC PUFA amount. The digestive lipolysis was first assessed using an in vitro enzymatic model. Then, intestinal absorption and enterocyte metabolism were investigated in vivo, on male Wistar rats through lymph lipid analysis. The in vitro results showed that the release of n-3 LC PUFA from lipolysis was increased by 48 % when FA were provided as PL rather than TAG. The in vivo results demonstrated that EPA and DHA from both TAG and PL were similarly absorbed and incorporated into lymph lipids. However, DHA was mainly distributed at the sn-1/3 positions of lymph TAG when provided as marine PL, whereas it was equally distributed at the three positions with marine TAG. On the whole, even if the molecular lipid species of n-3 LC PUFA did not greatly modify the in vivo digestion and absorption steps, it modulated the rearrangement of DHA on the glyceride positions of the lymph TAG, which may further impact the DHA metabolic fate and tissue accretion. Consequently, the present study has provided data which may be used to formulate lipid diets rich in DHA in the context of an insufficient consumption of n-3 PUFA in Western countries.

Lipid transmethylation methods described in the literature are not always evaluated with care so to insure that the methods are effective, especially on food matrix or biological samples containing polyunsaturated fatty acid (PUFA). The aim of the present study was to select a method suitable for all lipid species rich in long chain n-3 PUFA. Three published methods were adapted and applied on individual lipid classes. Lipid (trans)methylation efficiency was characterized in terms of reaction yield and gas chromatography (GC) analysis. The acid-catalyzed method was unable to convert triglycerides and sterol esters, while the method using an incubation at a moderate temperature was ineffective on phospholipids and sterol esters. On the whole only the method using sodium methoxide and sulfuric acid was effective on lipid classes taken individually or in a complex medium. This study highlighted the use of an appropriate (trans)methylation method for insuring an accurate fatty acid composition., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The brain is highly enriched in long chain polyunsaturated fatty acids (LC-PUFAs) that are esterified into phospholipids, the major components of cell membranes. They accumulate during the perinatal period when the brain is rapidly developing. Hence, the levels of LC-PUFAs in the brains of the offspring greatly depend on maternal dietary intake. Perinatal n-3 PUFA consumption has been suggested to modulate the activity of microglial cells, the brain's innate immune cells which contribute to the shaping of neuronal network during development. However, the impact of maternal n-3 PUFA intake on microglial lipid composition in the offspring has never been studied. To investigate the impact of maternal dietary n-3 PUFA supply on microglia lipid composition, pregnant mice were fed with n-3 PUFA deficient, n-3 PUFA balanced or n-3 PUFA supplemented diets during gestation and lactation. At weaning, microglia were isolated from the pup's brains to analyze their fatty acid composition and phospholipid class levels. We here report that post-natal microglial cells displayed a distinctive lipid profile as they contained high levels of eicosapentaenoic acid (EPA), more EPA than docosahexaenoic acid (DHA) and large amount of phosphatidylinositol (PI) / phosphatidylserine (PS). Maternal n-3 PUFA supply increased DHA levels and decreased n-6 docosapentaenoic acid (DPA) levels whereas the PI/PS membrane content was inversely correlated to the quantity of PUFAs in the diet. These results raise the possibility of modulating microglial lipid profile and their subsequent activity in the developing brain., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Purpose: In numerous epidemiological studies, omega-3 polyunsaturated fatty acids (PUFAs) have been associated with a decreased risk of age-related macular degeneration (AMD). Beyond their structural, functional and neuroprotective roles, omega-3 PUFAs may favour the retinal accumulation of lutein and zeaxanthin and thus increase macular pigment optical density (MPOD). We examined the associations of MPOD with plasma omega-3 PUFAs in subjects with family history of AMD., Methods: The Limpia study is a double-blind, placebo-controlled, prospective randomized clinical trial performed in 120 subjects. Subjects with at least one parent treated for neovascular AMD, aged 40-70, with a best corrected visual acuity (BCVA) >20/25, free of late AMD and other major eye conditions and with no use of supplement containing lutein or zeaxanthin the preceding year were recruited in Bordeaux and Dijon, France. At baseline, MPOD within 1° of eccentricity was measured by modified Heidelberg retinal analyser (Heidelberg, Germany) and plasma omega-3 PUFAs by gas chromatography. Medical history and lifestyle data were collected from a standardized questionnaire. Associations of MPOD with plasma omega-3 PUFAs were assessed at the baseline examination, using mixed linear models adjusted for age, gender, centre, body mass index, smoking, plasma high-density lipoprotein (HDL) cholesterol and lutein+zeaxanthin., Results: After multivariate adjustment, high MPOD was significantly associated with higher level of plasma docosapentaenoic acid (DPA) (β = 0.029, 95% CI: 0.003, 0.055; p = 0.03). Plasma alpha linolenic, eicosapentaenoic and docosahexaenoic acids were not significantly associated with MPOD., Conclusion: In the Limpia study, high MPOD within 1° was significantly associated with higher plasma levels of omega-3 DPA., (© 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Background: Long-chain polyunsaturated fatty acids (LC-PUFAs) are important for newborn neurosensory development. Supplementation of breastfeeding mothers' diets with omega-3 PUFAs, such as alpha-linolenic acid (ALA), may increase their concentration in human milk. Research aim: This study aimed to assess human milk composition after 15-day supplementation regimens containing either omega-3 PUFAs or olive oil, which does not provide ALA., Methods: A multicenter factorial randomized trial was conducted with four groups of breastfeeding women, with each group containing 19 to 22 women. After a 15-day ALA washout period, three groups received supplementation with omega-3 precursors for 15 days: an enriched margarine (M), a rapeseed oil (R), and a margarine and rapeseed oil (MR). The fourth was unexposed to omega-3 precursors (olive oil control diet, O). After 15 days, blind determination of human milk fatty acid (FA) composition was assessed by gas chromatography, and the FA composition was compared among groups using variance analyses., Results: Alpha-linolenic acid content, expressed as the mean (standard deviation) total human milk FA percentage, was significantly higher after diet supplementation with omega-3 PUFAs, with values of 2.2% (0.7%) (MR), 1.3% (0.5%) (R), 1.1% (0.4%) (M), and 0.8% (0.3%) (O at D30) ( p < .003 for each comparison). The lowest LA-ALA ratio (5.5) was found in the MR group ( p < .001). Docosahexaenoic acid and trans FA concentrations did not differ among groups., Conclusion: In lactating women, omega-3 supplementation via the combination of enriched margarine and rapeseed oil increased the ALA content of human milk and generated the most favorable LA-ALA ratio for LC-PUFA synthesis.

Purpose: To assess the correlation between macular pigment optical density and plasma levels of lutein, zeaxanthin, and fatty acids, especially omega-3 polyunsaturated fatty acids (PUFAs)., Methods: The PIMAVOSA study is an observational study of 107 healthy volunteers, aged 20 to 60 years and born in southwest France, without histories of ocular disease. Macular pigment optical density (MPOD) was measured using the two-wavelength autofluorescence method with a modified scanning laser ophthalmoscope. Plasma measurements (lutein, zeaxanthin, and fatty acids) were performed from fasting blood samples collected on the day of the eye examination., Results: MPOD within 6° correlated with plasma levels of lutein and zeaxanthin (r = 0.35, P < 0.001, and r = 0.30, P < 0.005, respectively). MPOD also significantly correlated with total plasma omega-3 PUFAs (r = 0.22, P < 0.05). Among the different omega-3 PUFAs, docosapentaenoic acid (DPA) had the highest correlation with MPOD (r = 0.31, P < 0.001), whereas correlation with eicosapentaenoic acid (EPA) was moderate (r = 0.21, P < 0.05) and did not reach statistical significance for docosahexaenoic acid (r = 0.14, P = 0.14)., Conclusions: In the present study, macular pigment density was associated not only with plasma lutein and zeaxanthin but also with omega-3 long-chain PUFAs, particularly with EPA and DPA. Further studies will be needed to confirm these findings and to identify the underlying mechanisms.