<p>Obesity is today a problem that has reached epidemic proportions. One of the causes of obesity is the over-consumption of energy. Fat is the most energy-dense nutrient, where the quality seems to be more important for the development of the metabolic diseases than the quantity. The fatty acid composition in serum lipid fractions can be used to mirror the dietary fat quality.</p><p>Stearoyl-CoA-desaturase (SCD) is an enzyme that converts saturated to monounsaturated fatty acids. A surrogate measure of SCD activity can be estimated as a fatty acid ratio; 16:1/16:0 (palmitoleic acid/palmitic acid) and 18:1/18:0 (oleic acid/stearic acid). The aim of this project was to investigate the intra-day variation in the SCD-ratio in humans eating a standardized diet. The results showed that triacylglycerol and nonesterified fatty acid fractions in serum lipids had a significant variance in the 16:1/16:0 ratio during the day, whereas 18:1/18:0 ratio in the same fractions did not exhibit the same pattern. In this study 16:1/16:0 ratio also seems to be a better marker than 18:1/18:0 ratio for estimating SCD activity. For further evaluation of the intra-day variation there need to be a more long-term study of the SCD-activity for a larger group of subjects.</p>

Obesity is today a problem that has reached epidemic proportions. One of the causes of obesity is the over-consumption of energy. Fat is the most energy-dense nutrient, where the quality seems to be more important for the development of the metabolic diseases than the quantity. The fatty acid composition in serum lipid fractions can be used to mirror the dietary fat quality. Stearoyl-CoA-desaturase (SCD) is an enzyme that converts saturated to monounsaturated fatty acids. A surrogate measure of SCD activity can be estimated as a fatty acid ratio; 16:1/16:0 (palmitoleic acid/palmitic acid) and 18:1/18:0 (oleic acid/stearic acid). The aim of this project was to investigate the intra-day variation in the SCD-ratio in humans eating a standardized diet. The results showed that triacylglycerol and nonesterified fatty acid fractions in serum lipids had a significant variance in the 16:1/16:0 ratio during the day, whereas 18:1/18:0 ratio in the same fractions did not exhibit the same pattern. In this study 16:1/16:0 ratio also seems to be a better marker than 18:1/18:0 ratio for estimating SCD activity. For further evaluation of the intra-day variation there need to be a more long-term study of the SCD-activity for a larger group of subjects.

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Part I of this thesis deals with general methodology and the experimental work can be clearly divided into two sections. Part II deals with studies carried out chiefly to determine further the epidemiological factors influencing serum lipid (and in particular, serum triglyceride) levels in the population groups of Southern Africa. The original objectives are described on page 70 and the main conclusions summarised on page 114. Part III describes three studies which were conducted in an attempt to fill some of the gaps in the considerable literature on the relationship between dietary carbohydrate and serum lipids in man. Both in the review of the literature at the beginning of this section and in the interpretation of the results of each of the studies, discussion has been chiefly limited to experiments conducted in man. There is a great deal of information available on studies carried out in experimental animals which show marked species differences from man with regards kinetic behaviour of serum and liver triglycerides(l). Where relevant, of course, reference has been made to these studies. The significance of each of the three studies has been discussed separately, but the principal objectives are mentioned on page 138 and the general conclusions are summarised on page 205.

The cardiovascular diseases consist of a public health problem of determined by a complex network of risky factors, with distinction to those related to the life style. Coffee consumption has been pointed out as one of these factors, based on the proposal of which the diterpenes there present would raise the cholesterol and serum triglycerides, one of the most important factors of cardiovascular risk. In this context, objectifying to contribute in the discussion of this problem in focus, this dissertation presents two articles: a revision of literature concerning substances present in the coffee drink and its relation to the systemic arterial and dyslipidemias hypertension, and an original article that presents a transversal study where the association between the consumption of coffee and serum lipid profile in hypertensions and diabetics type 2 were verified. Studies on the identification of substances present in coffee and the relation of many of them to the health have been growing in the last few decades, which is understood because of the fact that coffee is one of most popular drinks, world-widely consumed, as well as for its economic importance in Brazil and in the European countries. The caffeine, mainly the cafestol and kahweol diterpenes and the chlorogenic acids are the composites most discussed in this dissertation. Emphasis is given to the preparation methods of the coffee drink, consumption and dilution, and the possible relation of these factors with the serum lipid profile and dyslipidemias. / Fundação de Amparo a Pesquisa do Estado de Alagoas / As doenças cardiovasculares constituem um problema de saúde pública determinado por uma complexa rede de fatores de risco, com destaque para aqueles relacionados ao estilo de vida. O consumo de café tem sido apontado como um destes fatores, baseado na proposição de que os diterpenos ali presentes elevariam o colesterol e triglicerídeos séricos, um dos mais importantes fatores de risco cardiovascular. Neste contexto, objetivando contribuir na discussão deste problema em foco, esta dissertação apresenta dois artigos: uma revisão da literatura acerca das substâncias presentes na bebida café e a sua relação com a hipertensão arterial sistêmica e dislipidemias e um artigo original que apresenta um estudo transversal onde foi verificada a associação entre consumo de café e perfil lipídico sérico em hipertensos e diabéticos tipo 2 . Estudos de identificação de substâncias presentes no café e da relação de muitas delas com a saúde vêm crescendo nas últimas décadas, o que é explicado pelo fato do café ser uma das bebidas mais populares, mundialmente consumida, bem como pela sua importância econômica no Brasil e no mundo ocidental. A cafeína, principalmente os diterpenos cafestol e kahweol e os ácidos clorogênicos são os compostos mais discutidos nesta dissertação. Ênfase é dada aos métodos de preparo da bebida café, consumo e diluição e, a possível relação destes fatores com o perfil lipídico sérico e dislipidemias.

Made available in DSpace on 2014-07-29T16:16:33Z (GMT). No. of bitstreams: 1 Fernandes DC 2011.pdf: 372122 bytes, checksum: e2a86ba2aff621dd5ddc47d727122a8d (MD5) Previous issue date: 2011-03-28 / The aim of this study was to evaluate the effect of the intake of baru almond, peanut and brazil nut in lipid profile and in lipid peroxidation in rats that were fed with high-fat diet. The effect of baru almond, peanut and brazil nut intakes in lipid profile and in lipid peroxidation were evaluated by bioassay with young adults Wistar rats during two months. The diets were formulated according to American Institute of Nutrition (AIN-93G): 5 fat diets (0.1% cholic acid + 1% cholesterol + 5% lard + 15% of one the fat sources lard and olive oil [controls], baru almond, peanut or brazil nut) and a standard diet (7% soybean oil). Blood samples were collected in order to determine the serum lipid profile and the samples of the animal liver were collected in order to evaluate total malondialdehyde (total MDA), reduced glutathione and vitamin E. Peanut modulated the lipid profile in rats with high-fat diet, decreasing levels of total cholesterol (TC= 84 mg.dL-1) and triglycerides (TG= 46 mg.dL-1), and increased levels of HDL-cholesterol (HDL-c= 44 mg.dL-1), when compared to lard-control (TC= 217 mg.dL-1, TG= 223 mg.dL-1, HDL-c= 24 mg.dL-1) and olive oil-control (TC= 111 mg.dL-1, TG= 39 mg.dL-1, HDL-c= 36 mg.dL-1). The baru almond reduced total cholesterol (TC= 126 mg.dL-1) and triglycerides (61 mg.dL-1), and increased the level of HDL-C (36 mg.dL-1), compared to lard-control. The brazil nut reduced the levels of total cholesterol (119 mg.dL-1) and triglycerides (57 mg.dL-1) in relation to the control lard, but did not increased the level of HDL-c (23 mg.dL-1). The peanut, baru almond and brazil nut reduced lipid peroxidation (total MDA: baru almond= 92 mmol.g protein-1; peanut= 89 mmol.g protein-1; brazil nut= 154 mmol.g protein-1) compared to the lard-control (Total MDA= 346 mmol.g protein-1). Peanut consumption improved GSH (4.3 &#956;mol.g protein-1) and vitamin E (15.2 &#956;mol.g tissue-1) levels, as compared to the baru almond (GSH = 1.8 &#956;mol.g-1 protein; vitamin E = 10.8 &#956;mol.g tissue-1) and the brazil nut (GSH = 1.6 &#956;mol.g-1 protein; vitamin E = 11.6 &#956;mol.g tissue-1). It is recommended the association of these foods in a healthy diet, or as a coadjuvant to reduce the risk of dyslipidemia in populations that consume high-fat diets, replacing, preferably, foods with high content of saturated fat. / O presente estudo teve o objetivo de avaliar o efeito da ingestão de amêndoa de baru, amendoim e castanha-do-pará no perfil sérico e na peroxidação de lipídios em ratos tratados com dieta hiperlipídica. O efeito da ingestão desses alimentos no perfil sérico e na peroxidação de lipídios foi avaliado por meio de ensaio biológico com ratos Wistar, machos, adultos jovens, durante dois meses. As dietas foram formuladas segundo o American Institute of Nutrition (AIN-93G), sendo cinco dietas hiperlipídicas (0,1% de ácido cólico + 1% de colesterol + 5% de banha + 15% de uma das fontes lipídicas banha e azeite [controles], amêndoa de baru, amendoim ou castanha-do-pará) e uma dieta padrão (7% de óleo de soja). Ao final do experimento, foram coletados o sangue, para determinação do perfil lipídico sérico, e o fígado, para avaliar os níveis de malondialdeído total (MDA total), glutationa reduzida (GSH) e vitamina E hepáticas. O amendoim modulou o perfil lipídico sérico de ratos com dieta hiperlipídica, reduzindo os níveis de colesterol total (CT= 84 mg.dL-1) e triglicérides (TG= 46 mg.dL-1), e aumentando os níveis de HDL-colesterol (HDL-c=44 mg.dL-1), em relação ao controle-banha (CT= 217 mg.dL-1; TG= 223 mg.dL-1; HDL-c= 24 mg.dL-1) e ao controle-azeite (CT= 111 mg.dL-1; TG= 39 mg.dL-1; HDL-c= 36 mg.dL-1). A amêndoa de baru reduziu o colesterol total (126 mg.dL-1) e triglicérides (61 mg.dL-1), e aumentou os níveis de HDL-c (36 mg.dL-1), em comparação ao controle-banha. A castanhado- pará reduziu os níveis de colesterol total (119 mg.dL-1) e triglicérides (57 mg.dL-1) em relação ao controle banha, mas não aumentou os níveis de HDL-c (23 mg.dL-1). O amendoim, a amêndoa de baru e a castanha-do-pará reduziram a peroxidação lipídica (MDA total: amendoim= 89 mmol.g proteina-1; amêndoa de baru= 92 mmol.g proteina-1; castanha-dopará= 154 mmol.g proteina-1), em relação ao controle-banha (346 mmol.g proteína-1), sendo este efeito mais acentuado para o amendoim, pois ainda manteve os níveis de GSH (4,3 &#956;mol.g proteína-1) e de vitamina E (15,2 &#956;mol.g tecido-1) hepáticos elevados, em comparação à amêndoa de baru (GSH= 1,8 &#956;mol.g proteína-1; vitamina E= 10,8 &#956;mol.g tecido-1) e à castanha-do-pará (GSH= 1,6 &#956;mol.g proteína-1; vitamina E= 11,6 &#956;mol.g tecido-1). Recomenda-se a associação desses alimentos em uma dieta saudável, ou ainda, como coadjuvantes na redução do risco de dislipidemias em grupos populacionais que consomem dietas hiperlipídicas, como substitutos, preferencialmente, de alimentos ricos em gordura saturada.