Ingestão de ácidos graxos monoinsaturados e metabolismo lipídico / Monounsaturated fatty acid intake and lipid metabolism

Esta revisão teve como objetivo apresentar e discutir os achados mais recentes do efeito dos ácidos graxos monoinsaturados (AGMI) sobre marcadores plasmáticos do metabolismo lipídico em estudos pós-prandiais e de intervenção clínica nutricional. Realizou-se busca em diferentes bases de dados entre 2010 e 2014, usando os seguintes termos de indexação: MUFA, Lipemia, Lipid Metabolism, Triglycerides e Postprandial. O consumo de refeição com alto conteúdo de AGMI tem demonstrado efeito benéfico na resposta lipidêmica pós-prandial, mas se essa resposta pode ser alterada em indivíduos com excesso de peso e/ou outras doenças crônicas após consumo de AGMI, ainda não está totalmente elucidado. De modo geral, após a intervenção com AGMI, os fatores de risco cardiovascular diminuíram, além de haver melhora no perfil lipídico. Em conclusão, os estudos recentes têm demonstrado um efeito benéfico do consumo de AGMI em curto e longo prazos, mediante aumento/manutenção das concentrações de HDL colesterol e diminuição do LDL colesterol.

The objective of this review is to present and discuss the most recent findings related to the effects of monounsaturated fatty acids (MUFA) on plasma markers of lipid metabolism observed in postprandial studies and clinical nutritional intervention studies. Searches were conducted on several different databases for publications from 2010 to 2014 using the following keywords: MUFA, Lipemia, Lipid Metabolism, Triglycerides and Postprandial. High-MUFA meal has presented beneficial effect on postprandial lipidemia response, but it is not yet completely clear whether this response to MUFA intake may be different in people with excess weight and/or other chronic diseases. In general, cardiovascular risk factors were reduced and lipid profiles improved after interventions with MUFA. In conclusion, recent studies have demonstrated that consuming MUFA has beneficial effects at short and long time by increasing/maintaining HDL-cholesterol concentrations and reducing levels of LDL cholesterol.

Trabajos de Investigación Increase of plasma fatty acids without changes in n-6/n-3-PUFA ratio in asymptomatic obese subjects / Aumento de las concentraciones plasmáticas de ácidos grasos sin cambio en el ratio de n-6/n-3 PUFA en sujetos obesos asintomáticos

Obesity is associated with a low grade inflammation which contributes to the development of insulin resistance and diabetes. The aim of this study was to assess the total saturated (SFAs), monounsaturated (MUFAs) and polyunsaturated fatty acids (PUFAs) in plasma from asymptomatic obese subjects and to determine the arachidonic/eicosapentanoic acid ratio [ARA/EPA] as a marker of inflammation, and its eventual association with ultrasensitive CRP. Fourteen obese (34.4 ± 11.1y.; BMI: 36.0 ± 4,5 kg/m2) and 12 normal-weight (30.6 ± 7.8y.; BMI: 23,6± 2,4 kg/m2) subjects were recruited and their plasma fatty acids were determined by gas chromatography. usCRP was higher in the obese subjects (p=0,01) and correlates with their body fat content. The percentages of SFAs, MUFAs, PUFAs were not affected in the obese subjects but their concentrations were increased, compared with the control group. However, no differences in the long chain PUFAs (DHA and EPA) concentrations or in the plasmatic ARA/EPA ratio were observed in these subjects. These observations do not support a relation between the ARA/EPA ratio and the presence of low grade inflammation evaluated by plasma usCRP in this group of asymptomatic obese subjects.

La obesidad está asociada con una inflamación de bajo grado que contribuye al desarrollo de la insulino-resistencia y de la diabetes. El objetivo de este estudio fue evaluar las concentraciones plasmáticas de ácidos grasos saturados (AGS), monoinsaturados (AGMI) y poliinsaturados (AGPI) en sujetos obesos asintomáticos y determinar el ratio ácido araquidónico/ácido eicosapentanoico [ARA/EPA] como un posible marcador de inflamación, con su eventual asociación con los niveles de proteína C reactiva ultrasensible (PCRus). Se reclutaron 14 sujetos obesos (34,4 ± 11.1 años; índice de masa corporal: 36,0 ± 4,5 kg/m2) y 12 normopeso (30,6 ± 7.8 años; índice de masa corporal: 23,6 ± 2,4 kg/m2); las concentraciones plasmáticas de ácidos grasos fueron determinados por cromatografía de gases. Los niveles de PCRus fueron más elevadas en los sujetos obesos (p=0,01) y correlacionaron con el contenido de grasa corporal. Los porcentajes relativos de AGS, AGMI, AGPI no se vieron afectados en los sujetos obesos, pero sus concentraciones plasmáticas se incrementaron en comparación con el grupo control. Sin embargo, no se observaron diferencias en las concentraciones de PUFAs de cadena larga (DHA, EPA y ARA) ni en el ratio ARA/EPA en los sujetos obesos. Estas observaciones no apoyan el uso del ratio ARA/EPA como un marcador de inflamación de bajo grado evaluada por PCRus en este grupo de sujetos obesos asintomáticos.

Histological changes in renalvessels of albino rats fed on canola oil and hyperlipidaemic diet

To evaluate and compare the atheroscIerotic changes with intake of dietary monounsaturated fatty acid [canola oil] and hyperlipidaemic diet on the renal arteries of albino rats. Design: It was an experimental study conducted at Postgraduate Medical lnstitute [PGMI] Lahore for 24 weeks. Materials and Methods Sixty albino rats of 8 weeks age, equal number of males and females were divide in to five groups of 12 animals each.[Group DO-4]. Different diets were prepared and given to the animals for 24 weeks. Renal arteries were taken to see changes. Gross and microscopic changes for atherosclerosis were studied in animals sacrificed after one week [Group DO] and in animals scarified after 24 weeks of experiment [Groups 1-4]. Only one animal showed atherotic lesion in-group D 2, while all other animals remained lesion free. Our study proved that canola oil was one of the beneficial diets. Canola oil was not only effective when used alone in the diet but it also protected and prevented the atherosclerotic changes of other atherogenic diets

Incorporation of dietary trans monounsaturated fatty acids into tissues of Walker 256 tumor-bearing rats

The correlation between dietary trans fatty acids and neoplasia was examined in the present study. Walker 256 tumor-bearing and control rats were fed a trans monounsaturated fatty acid (MUFA)-rich diet for 8 weeks and the incorporation of trans fatty acids by tumor tissue was examined. Also, the effect of tumor growth on trans fatty acid composition of plasma and liver, and the content of thiobarbituric acid-reactive substances (TBARS) was determined. Walker 256 tumor cells presented both trans and cis MUFAs given in the diet. The equivalent diet proportions were 0.66 for trans and 1.14 for cis. Taking into consideration the proportion of trans MUFAs in plasma (11.47 percent), the tumor incorporated these fatty acids in a more efficient manner (18.27 percent) than the liver (9.34 percent). Therefore, the dietary trans fatty acids present in the diet are actively incorporated by the tumor. Tumor growth itself caused marked changes in the proportion of polyunsaturated fatty acids in the plasma and liver but provoked only slight modifications in both trans and cis MUFAs. Tumor growth also reduced the unsaturation index in both plasma and liver, from 97.79 to 86.83 and from 77.51 to 69.64, respectively. This effect was partially related to an increase in the occurrence of the lipid oxidation/peroxidation process of TBARS content which was increased in both plasma (from 0.428 to 0.505) and liver (from 9.425 to 127.792) due to tumor growth