Dietary fatty acid metabolism: New insights into the similarities of lipid metabolism in humans and hamsters

[EN] Hamsters have been long accepted as animal models to study the lipid metabolism in humans. However, very few scientific works described in detail the fatty acid (FA) composition of plasma and erythrocytes in hamsters in relation to their dietary intake, and none work was found comparing them with that described in humans. Therefore, a study was carried out to compare the effect of ingesting olive oil or dairy fat, as part of an equilibrated diet in healthy subjects, on plasma and erythrocytes FA composition. More than 40 FA were detected in samples of both species. It was demonstrated that plasma total FA (TFA) concentration and FA profiles are similar in humans and hamsters. In both species linoleic, oleic and palmitic acids are the main FA and accounted for the 70% of TFA. Differences found between species can be explained by differences in the dietary intake and differences in the proportion of triglycerides, cholesteryl esters and phospholipid fractions in plasma of both species. Changes in dietary FA intake causes similar changes in FA concentration in the plasma of both species and can be explained by the same metabolic processes. The erythrocyte FA profile differs more between the two species. Moreover, unlike humans, the FA profile of hamster erythrocytes is more sensitive to changes in dietary FA than that of plasma

Normal-Fat vs. High-Fat Diets and Olive Oil vs. CLA-Rich Dairy Fat: A Comparative Study of Their Effects on Atherosclerosis in Male Golden Syrian Hamsters

The relationship between milk fat intake (because of its high saturated fatty acid content) and the risk of suffering from cardiovascular diseases remains controversial. Thus, Golden Syrian hamsters were fed two types of fat—sheep milk fat that was rich in rumenic (cis9,trans11-18:2) and vaccenic (trans11-18:1) acids and olive oil—and two doses (a high- or normal-fat diet) for 14 weeks, and markers of lipid metabolism and atherosclerosis evolution were analyzed. The results revealed that the type and percentage of fat affected most plasma biochemical parameters related to lipid metabolism, while only the expression of five (CD36, SR-B1, ACAT, LDLR, and HMG-CoAR) of the studied lipid-metabolism-related genes was affected by these factors. According to aortic histology, when ingested in excess, both fats caused a similar increase in the thickness of fatty streaks, but the high-milk-fat-based diet caused a more atherogenic plasma profile. The compositions of the fats that were used, the results that were obtained, and the scientific literature indicated that the rumenic acid present in milk fat would regulate the expression of genes involved in ROS generation and, thus, protect against LDL oxidation, causing an effect similar to that of olive oil.This research was funded by the Basque Government (Grant to Research Groups IT944-16). A.B. and G.S.-G. received a research grant from the University of the Basque Country (calls 2009 and 2019, respectively)

The Sum of Plasma Fatty Acids iso16:0, iso17:0, trans11-18:1, cis9, trans11-CLA, and cis6-18:1 as Biomarker of Dairy Intake Established in an Intervention Study and Validated in the EPIC Cohort of Gipuzkoa

The questioned reliability of 15:0, 17:0, and trans9-16:1 acids as biomarkers of dairy fat intake also questions the relationship between the intake of these products and their health effects. Two studies were conducted in the same geographical region. In an intervention study, volunteers followed a diet rich in dairy products followed by a diet without dairy products. Plasma and erythrocyte fatty acids (FA) were analyzed, and their correlations with dairy product intakes were tested. The FA biomarkers selected were validated in the Gipuzkoa cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC) observational study. The correlation coefficients between plasma concentrations of iso16:0, iso17:0, trans11-18:1, cis9, trans11-18:2, and cis6-18:1 and the dairy fat ingested are similar in both studies, indicating that their concentration increases by 0.8 µmol/L per gram of dairy fat ingested. The biomarkers are positively related to plasma triglycerides (r = 0.324 and 0.204 in the intervention and observational studies, respectively) and total cholesterol (r = 0.459 and 0.382), but no correlation was found between the biomarkers and atherogenicity indexes. In conclusion, the sum of the plasma concentration of the selected FAs can be used as biomarkers of dairy product consumption. A linear relationship exists between their plasma concentrations and ruminant product intake. These biomarkers allow for obtaining consistent relationships between dairy intake and plasma biochemical parameters.This research was funded by Basque Government (grant to Research Groups IT944-16). A.B. received a research grant from the University of the Basque Country, call 2009

La investigación científica en el queso Idiazabal

Desde hace unos 15 años el queso Idiazabal ha sido objeto de una extensa investigación científica. Se describen algunos de los principales factores que inciden directamente en su calidad sensorial e higiénico-sanitaria, tanto durante el proceso de elaboración como durante los meses que dura la maduración. Entre estos factores destacamos el cuajo artesanal en pasta y la alimentación de las ovejas.Idiazabal gaztari buruzko zientzia-azterketa ugari egin izan dute azken 15 urteotan. Azterketa horiek agerian utzi dituzte gaztaren kalitatea eragiten duten eragileak, bai zentzumen-ezaugarrien aldetik baita higienearen eta osasunaren ikuspegitik ere, gazta egiteko prozesuan zein gazta heltzeko hilabeteetan zehar. Eragile horien artean, artisautza-gatzagia eta ardien elikadura azpimarratu ditzakegu.Depuis 15 ans, le fromage Idiazabal fait l'objet d'un vaste travail de recherche scientifique. Il comprend la description des principaux facteurs qui influent directement sur sa qualité sensorielle et hygièno-sanitaire, aussi bien durant le processus d'élaboration que pendant la période de maturation. Des facteurs tels que, notamment, la présure artisanale en pâte et l'alimentation des brebis.Idiazabal cheese has been extensively studied from a scientific perspective for the last 15 years. The present article describes some of the main factors that directly influence its sensory and hygienic quality, both during the fabrication process and during the ripening period. Among these factors the artisanally-prepared rennet and the role of grazing are considered

Traditional part-time grazing: a more sustainable sheep milk and cheese production in the Basque Country

[EN] The concept of sustainability when referring to food production rests, in general, on 3 main aspects: 1) respect for the environment; 2) economic and social benefits for all involved in production; and 3) production of sufficient quantity of quality food at an accessible price. In this contribution we focus on the main aspects of the traditional sheep's milk and cheese production (under the Denomination of Origin Idiazabal Cheese) in the Basque Country that contribute primarily to its sustainability. It is based on the local latxa or carranzana breeds of sheep, adapted to the mountainous terrain. The sheepherder takes advantage of local resources to reduce management costs by combining indoor dry forage and concentrates with outdoor grazing throughout lactation, according to local pasture availability, and thus avoiding having to buy large amounts of feed. This system facilitates recycling of manure, fertilising pastures and forest at the same time. Use of local breeds helps maintain biodiversity of sheep breeds. Cheese is produced industrially (44.5% of the total cheese produced in 2008) from milk of many flocks, or artisanally (38.3%) by the sheepherders with the milk from their own flocks. Transforming their own milk into cheese is advantageous for the following reasons: 1) higher economic returns as compared to selling the milk to cheese factories because cheese price directly sold to consumers is more competitive than industrial cheese sold in supermarkets; 2) increases the value of women's work (over 80% of the cheese makers are women) in the community and their self-esteem; 3) it creates rural jobs and contributes to rural development; 4) we have demonstrated both with experimental and commercial flocks that part-time grazing allows the sheepherder to obtain high yields of milk, and cheese, of high nutritional and functional quality. Currently a less sustainable, intensive sheep's milk production with foreign, imported breeds kept indoors constantly is gaining favour among milk producers because of its perceived higher economic profitability

Traditional part-time grazing: a more sustainable sheep milk and cheese production in the Basque Country

[EN] The concept of sustainability when referring to food production rests, in general, on 3 main aspects: 1) respect for the environment; 2) economic and social benefits for all involved in production; and 3) production of sufficient quantity of quality food at an accessible price. In this contribution we focus on the main aspects of the traditional sheep's milk and cheese production (under the Denomination of Origin Idiazabal Cheese) in the Basque Country that contribute primarily to its sustainability. It is based on the local latxa or carranzana breeds of sheep, adapted to the mountainous terrain. The sheepherder takes advantage of local resources to reduce management costs by combining indoor dry forage and concentrates with outdoor grazing throughout lactation, according to local pasture availability, and thus avoiding having to buy large amounts of feed. This system facilitates recycling of manure, fertilising pastures and forest at the same time. Use of local breeds helps maintain biodiversity of sheep breeds. Cheese is produced industrially (44.5% of the total cheese produced in 2008) from milk of many flocks, or artisanally (38.3%) by the sheepherders with the milk from their own flocks. Transforming their own milk into cheese is advantageous for the following reasons: 1) higher economic returns as compared to selling the milk to cheese factories because cheese price directly sold to consumers is more competitive than industrial cheese sold in supermarkets; 2) increases the value of women's work (over 80% of the cheese makers are women) in the community and their self-esteem; 3) it creates rural jobs and contributes to rural development; 4) we have demonstrated both with experimental and commercial flocks that part-time grazing allows the sheepherder to obtain high yields of milk, and cheese, of high nutritional and functional quality. Currently a less sustainable, intensive sheep's milk production with foreign, imported breeds kept indoors constantly is gaining favour among milk producers because of its perceived higher economic profitability