Purpose: To assess whether the participation in food assistance programs (Community Kitchens and Glass of Milk) was associated with lipid profile patterns in the Peruvian population. We conducted a secondary data analysis using data from the National Survey of Nutritional, Biochemical, Socioeconomic, and Cultural Indicators related to Chronic Degenerative Diseases. The sample included individuals aged ≥20 years, selected from five geographic strata in Peru. From each stratum a random sample of clusters was chosen. Different Poisson regression models with robust variance were built to determine the association between food assistance programs and participant lipid profile (total cholesterol (TC), HDL-cholesterol (HDL-c), LDL-cholesterol and triglycerides (TG)). Data from 4028 participants was analyzed, 123 (3.1%) reported being beneficiaries of the Community Kitchens program and 827 (20.5%) were beneficiaries of the Glass of Milk program. An association between being a beneficiary of Community Kitchens and increased LDL-c (Prevalence ratio (PR)= 2.33; 95% CI: 1.18–4.59) was found. Being a beneficiary of the Glass of Milk program increased the probability of having low HDL-c levels (PR= 1.08; 95% CI: 1.02–1.14), but reduced the probability of hypertriglyceridemia (PR= 0.70; 95% CI: 0.56–0.88). Being a beneficiary of the Community Kitchen program was associated with increased LDL-c levels; while, being a beneficiary of the Glass of Milk increased the probability of low HDL-c, but reduced the probability of developing hypertriglyceridemia. / Revisión por pares

Increased triglyceride (TG) concentration has been generally accepted as a risk factor for ischemic heart disease and, therefore, lowering TG is therapeutic target that should reduce cardiovascular disease risk. Traditionally, concentration of TG is measured in the fasting state (8-12 hours after an overnight fasting) mainly because the rise in TG levels after meal leads to the high variation in TG values. However, human beings spend larger portion of the day in a postprandial state and postprandial hypertriglyceridemia may then play a substantial role in determination of cardiovascular disease risk. The increased and prolonged postprandial lipemia has been found in patients with coronary heart disease. Moreover, recent data from Copenhagen Heart Study point out that the non-fasting TG concentration is associated with cardiovascular disease risk more tightly than the fasting TG concentration. Importantly, concentration of non-fasting TG is substantially affected by individual behavioural habits such as diet composition and physical activity. It remains to be determined whether it would be appropriate to identify individuals at higher risk of cardiovascular disease due to increased postprandial TG using tolerance test analogous to glucose tolerance test. The protocol of standardized fat tolerance...

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The effect of a 53% oat bran diet and a 30% pinto bean diet on hamster plasma total cholesterol (TC) and triglycerides (TG) was investigated. Hamsters were made hypercholesterolemic (average value = 206 mg/dL) and then fed one of four experimental diets, the hypercholesterolemic control (HC), an insoluble fiber (alphacel) control (FC), the oat bran (OB), or the pinto bean (PB) diet for three weeks, with the latter three containing 8.5%, 10.0%, and 7.6%, total dietary fiber, respectively. Plasma TC and TG were measured for each animal before and after the experimental diets. At the end of the experimental period, plasma TC levels of hamsters fed the OB diet (179 mg/dL) were significantly lower than those fed either the HC (203 mg/dL, p<0.05) or FC (221 mg/dL, p<0.001) diets. Plasma TG levels of hamsters fed the OB diet (200 mg/dL) were significantly lower than those fed the FC diet (358 mg/dL, p<0.01). Thus, it was concluded that oat bran significantly lowered plasma TC and TG in hypercholesterolemic hamsters, while pinto beans did not. / Master of Science

Yes / Purpose: Raised postprandial triglycerides (TAG) and related oxidative stresses are strongly associated with increased cardiovascular disease (CVD) risk. Acute exercise and strawberry ingestion independently ameliorate postprandial lipid excursions and oxidative stress. However, the combined effects of these lifestyle interventions is unknown. We investigated whether acute exercise and strawberry consumption improved postprandial responses to an oral fat tolerance test (OFTT) in overweight/obese males. Methods: Overweight/obese adult males underwent four separate OFTT (73g fat, 33g carbohydrate) with blood sampled at baseline and hourly for 4 h after OFTT. Two OFTT contained 25g freeze-dried strawberries and two contained strawberry flavouring (placebo). Participants performed 40 minutes of submaximal high intensity interval cycling exercise (HIIE) 16 h before one strawberry and one placebo OFTT, and rested before the remaining two OFTT. Serum TAG was analysed and TAG area under curve (AUC) and incremental AUC (iAUC) were calculated. Oxidative stress markers were measured at baseline and 4 h. Differences between conditions (strawberry/placebo and exercise/rest) were assessed using repeated measures ANOVA. Results: Ten males (Age, 31.5 IQR 17.8 years; BMI, 29.9 ±1.8 kg.m-2) completed the study. TAG AUC was 1.5 mmol.4h-1.L-1 lower for the exercise conditions compared to the rest conditions (95% confidence interval [CI]= -2.3 to 0.8, p= 0.001). TAG AUC was not different between the strawberry and placebo conditions (CI= -1.3 to 0.6, p= 0.475). TAG iAUC was 0.5 mmol.4h-1.L-1 greater for the strawberry compared to the placebo conditions (CI= 0.1 to 1.0, p= 0.021). There were no changes in markers of lipid related oxidative stress (P> 0.05). Conclusion: Acute submaximal HIIE appears effective in reducing postprandial lipaemia in overweight/obese adult males. However, strawberry ingestion did not improve postprandial TAG.

The regulation of the serum triglyceride responses to fat ingestion have been examined in normolipidemic men. To evaluate the existing methods for comparing chylomicron-triglyceride clearance, the oral and intravenous fat tolerance tests and a steady state duodenal perfusion method were compared. Good correlations (r > 0.8) were found between each of these methods. Since the intravenous fat tolerance test is independent of fat absorption, these data suggested that the serum triglyceride response to fat feeding was largely determined by the rate of chylomicron-triglyceride clearance. To determine the influence of the quantity and type of meal fat on postprandial serum triglyceride concentrations, the serum triglyceride responses to three different doses of dairy cream, and to standard doses of olive and sunflower oil were examined. For a given type of fat, the magnitude of postprandial lipemia (the integrated serum triglyceride excursion) varied directly with the quantity of fat in the meal. This finding suggested that the chylomicron- triglyceride clearance system(s) did not become saturated even after large fat meals. In addition, it appeared that the hormonal factors released in response to fat ingestion (some of which are known to increase lipoprotein lipase activity in vitro) did not increase the rate of chylomicron-triglyceride clearance. If the quantity of fat in a meal was fixed, then postprandial lipemia increased with increasing saturation of the triglyceride fatty acids. These differences did not appear to reflect differences in triglyceride absorption. Since acute fat feeding per se did not appear to stimulate chylomicron-triglyceride clearance, the effects of dietary proteins and carbohydrates were studied. The addition of up to 35g protein to a standard test meal did not affect postprandial lipemia. These results were supported by the observation that protein ingestion did not affect intravenous fat tolerance. Postprandial serum triglyceride concentrations were significantly influenced by carbohydrate ingestion. Fructose (50g) and sucrose (100g) markedly increased postprandial lipemia, although glucose ingestion did not. In agreement with earlier studies, glucose ingestion decreased serum triglyceride concentrations 2 hours after the meal. This effect was abolished by intraduodenal fat administration and by substituting starch for glucose in the test meal. The effects of glucose could be reproduced by iso-osmotic quantities of urea, however. These findings suggested that glucose ingestion did not increase chylomicron -triglyceride clearance. It is more likely that glucose delayed the absorption of triglycerides by slowing gastric emptying, and that this effect was partly related to the increased osmolarity of glucose- containing meals. The effects of chronic exercise on postprandial lipemia and chylomicron-triglyceride clearance were determined in endurance- adapted athletes. The serum triglyceride responses to large and small fat meals were lower in athletes than in sedentary men with comparable fasting triglyceride concentrations. These differences were not eliminated by a single bout of acute exercise in the sedentary men. The clearance of intravenously administered lntralipid, and chylomicron -triglyceride clearance assessed from steady state chylomicron-triglyceride concentrations during duodenal fat perfusion were faster in athletes than in the sedentary men. These data suggested that the low postprandial lipemia in athletes reflects increased chylomicron-triglyceride clearance caused by increased activity of the triglyceride clearing system(s). Given these considerations. it appears that the pathway(s) for chylomicron triglyceride clearance are extremely efficient in normal men and that these pathways are not subject to acute physiological regulation.

Les dernières données de consommation alimentaire de la population française démontrent que les apports nutritionnels en acide eicosapentaénoïque (EPA) et en acide docosahexaénoïque (DHA) sont nettement inférieurs aux recommandations fixées par l’Agence nationale de sécurité sanitaire, de l’alimentation, de l’environnement et du travail (ANSES). Compte tenu de leurs rôles physiologiques, l’amélioration de leur biodisponibilité est devenue une priorité nutritionnelle. La maitrise des formes de vectorisation des acides gras polyinsaturés à longue chaine de la série n-3 (AGPI-LC n-3) représente une piste d’intérêt afin de répondre à cette problématique. C’est dans ce contexte que s’inscrit ce travail de thèse, visant à étudier l’influence de la forme moléculaire (phospholipides (PL) vs triglycérides (TG)) et/ou supramoléculaire (phase continue, émulsion, liposomes) de vectorisation des AGPI-LC n-3 sur leur devenir métabolique.La démarche expérimentale adoptée a consisté, dans un premier temps, à caractériser les différentes formes de vectorisation des AGPI-LC n-3 par un couplage de méthodes d’analyse physico-chimiques (microscopie optique, granulométrie, mesure des produits primaires et secondaires d’oxydation, lipolyse enzymatique). Les données obtenues ont permis de poser des hypothèses mécanistiques pour l’étude de la biodisponibilité chez le rat. Ainsi, dans un deuxième temps, l’étude in vivo a permis d’aborder (1) l’absorption intestinale des acides gras (AG) suite à un apport en bolus de lipides et (2) l’accrétion tissulaire suite à un régime de 8 semaines.Les résultats indiquent que la forme moléculaire de vectorisation des AGPI-LC n-3 (TG marins vs PL marins, en phase continue) n’influence pas leur absorption intestinale mais plutôt leur incorporation dans les lipides lymphatiques, principaux transporteurs des AG alimentaires dans l’organisme. A l’inverse, la structuration des PL marins en milieu aqueux (émulsion ou liposomes), permet d’améliorer l’absorption de l’EPA et du DHA, de façon spécifique à la nature de la structuration supramoléculaire. Les résultats de l’accrétion tissulaire montrent qu’au terme des 8 semaines de régime, l’enrichissement tissulaire en AGPI-LC n-3 s’effectue de façon différente selon leur forme moléculaire de vectorisation. Ainsi, la consommation de TG marins favorise l’incorporation des AGPI-LC n-3 dans les lipides hépatiques, alors que la supplémentation des régimes en PL marins permet d’orienter le DHA vers le cerveau et la rétine.L’ensemble de ces résultats montre que le choix de la forme moléculaire de vectorisation des AGPI-LC n-3 (PL vs TG) peut être un moyen d'orienter leur incorporation tissulaire, alors que leur structuration supramoléculaire (émulsion ou liposomes), une stratégie pour moduler leur absorption intestinale. / The latest data from the cross-sectional national French dietary study show that dietary intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are significantly lower than those recommended by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES). Considering their physiological roles, improving their dietary intake has became a nutritional priority. The control of the different forms of n-3 long chain polyunsaturated fatty (n-3 LC-PUFA) intake represents an interesting way to address this issue. In this context, this thesis aims at studying the influence of the molecular form (phospholipids (PL) vs triglycerides (TG)) and/or supramolecular form (continuous phase, emulsion, liposomes) of n-3 LC-PUFA towards their bioavailability.The experimental approach consisted in characterizing the different forms of n-3 LC-PUFAs by coupling various physicochemical methods (optical microscopy, granulometry, measurement of primary and secondary oxidation products, enzymatic lipolysis). The data obtained made it possible to propose some mechanistic hypothesis for the bioavailability studies conducted in rat. Thus, in a second step, the in vivo study made addresses (1) the intestinal absorption of fatty acids following a single dose of lipids and (2) the lipid tissue accretion following an 8-week diet.The data obtained from the intestinal absorption study indicate that the molecular form of n-3 LC-PUFA targeting (marine TG vs marine PL, in continuous phase) does not influence their intestinal absorption but rather their incorporation into lymphatic lipids, which are the main carriers for dietary fatty acids in the organism. Conversely, structuring marine PL (emulsion or liposomes) improves the EPA and DHA absorption, but differently according to the supramolecular form. The results concerning tissue accretion show that, after 8-week diet, the tissue enrichment in n-3 LC-PUFA is different according to the molecular form of targeting. The consumption of marine TG favours the incorporation of n-3 LC-PUFA into hepatic lipids, while the supplementation of diets with marine PL targets DHA preferentially to brain and retina.All these results show that the molecular form of targeting (PL vs TG) of n-3 LC-PUFA can be a way for managing their tissue incorporation, whereas the supramolecular organization (emulsion or liposomes) can be envisaged to monitor their intestinal absorption.

published_or_final_version / Chemistry / Master / Master of Philosophy