Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The mechanisms by which diets high in saturated fat (HFD) contribute to intestinal adaptation and obesity are unknown. The hypothesis that functional changes in distal portions of small intestine are induced by HFD was tested in C57B1/6 mice. Specifically, it was examined whether the putative fatty acid translocase CD36 was phosphorylated in mouse intestinal epithelial cells and whether dephosphorylation of CD36 increased long chain fatty acid (LCFA) absorption. Co-immunoprecipitation was used to investigate specific intestinal alkaline phosphatases that might interact with CD36. It was also examined whether chronic ingestion of an HFD would lead to upregulation of the CD36 and/or one or more intestinal alkaline phosphatases that may activate CD36. CD36 was found to be phosphorylated on the surface of mouse enterocytes, indicating that there may be a phosphatase-sensitive pool of phospho-CD36 (pCD36) in mouse small intestinal tissue. CD36 was dephosphorylated by alkaline phosphatase and this treatment increased long chain but not short chain fatty acid uptake. Long chain fatty acid uptake was blocked with a specific CD36 inhibitor. CD36 from mouse small intestines physically interacted specifically with global intestinal alkaline phosphatase (gIAP) but not duodenal alkaline phosphatase (dIAP). As expected, HFD increased body weight, adiposity, and plasma triglycerides compared to control mice. CD36 and gIAP but not dIAP protein levels were significantly increased in distal but not proximal regions of intestines of HFD mice. Finally, HFD increased the absorptive capacity of the distal small intestine for LCFA in a CD36-dependent manner. It is concluded that HFD specifically upregulates gIAP protein in epithelial cells of the distal regions of the small intestine of mice, and that one of its substrates is pCD36, which has been implicated in transcellular fat transport. This diet also increases the absorptive capacity of the distal small intestine for LCFAs. Taken together, these results suggest that HFD causes intestinal adaptation that results in an increased capacity to absorb dietary fat. This effect is mediated in part by increasing the expression and activity of the fatty acid transporter CD36 and its regulatory enzyme gIAP. / 2031-01-02

No description available.

Animal studies have shown that chronic high consumption of saturated fat (SF) leads to hypothalamic inflammation and ultimately, alters appetite control. This has been shown to be partly due to an increase in the activity of the transcription factor Nuclear Factor-κB (NF-κB), a major regulator of the inflammatory response. The goal of the study was to first confirm the association between SF measurements and anthropometric traits, then to determine the association between single nucleotide polymorphisms (SNPs) in the NF-κB1 gene and body mass index (BMI) and waist circumference (WC), and finally, to test the interaction between variants in this gene and dietary SF and circulating saturated fatty acids (CSFA) on these anthropometric traits in young adults. A significant positive association was identified between quartiles of CSFA and anthropometric measurements in the total sample (BMI: p = 0.0003, WC: p = 0.0001) and in South Asians (BMI: p = 0.004, WC: p = 0.01), but only marginally among Caucasians (BMI: p = 0.08, WC: p = 0.051) and East Asians (BMI: p = 0.13, WC: p = 0.053). After correcting for false discovery rate, carriers of the T allele in SNP rs4648022 had higher BMI and WC compared to those with the dominant CC genotype (p = 0.0003 and p = 0.0001, respectively). Among Caucasians, there was a significant interaction between SNPs in the NF-κB1 gene and quartiles of CSFA on WC for rs4648095 (p = 0.002). Thus, certain SNPs in the NF-κB1 gene appear to influence BMI and WC and also to modify the association between CSFA and anthropometric traits.

No description available.

2 pp. / [Healthy Fats -- Guide for Improving the Quality of Fat Intake] / The fact sheet reviews healthy fats and how to incorporate a healthy amount of fat into our diet. Fats are necessary for our bodies to function properly. In fact, fats are an important part of a healthy diet and we can't live without them. Fats can be grouped into two groups: saturated and unsaturated. Unsaturated fats include polyunsaturated and monounsaturated fats. Both these fats, when eaten in moderation and used in place of saturated and trans fats, can help lower cholesterol levels and decrease the risk of heart disease. We provide a list of "Do's" and "Tips" which gives examples of how to select fats wisely and incorporate healthy changes into our diet. We also provide a guide for selecting an appropriate portion size of fat.

2 pp. / The fact sheet reviews healthy fats and how to incorporate a healthy amount of fat into our diet. Fats are necessary for our bodies to function properly. In fact, fats are an important part of a healthy diet and we can't live without them. Fats can be grouped into two groups: saturated and unsaturated. Unsaturated fats include polyunsaturated and monounsaturated fats. Both these fats, when eaten in moderation and used in place of saturated and trans fats, can help lower cholesterol levels and decrease the risk of heart disease. We provide a list of "Do's" and "Tips" which gives examples of how to select fats wisely and incorporate healthy changes into our diet. We also provide a guide for selecting an appropriate portion size of fat.

A lipoproteína de alta densidade (HDL) tem várias ações protetoras contra o desenvolvimento de doenças cardiovasculares, como remover o excesso de colesterol dos tecidos periféricos. No entanto, outros aspectos do metabolismo da HDL, como o transporte de colesterol das outras classes de lipoproteínas para a HDL devem ser avaliados para verificar a sua ação protetora. Sendo assim, nosso objetivo foi verificar, em hamsters, se a dieta hiperlipídica altera fatores relacionados ao metabolismo da HDL, tais como a composição da fração HDL e a transferência simultânea de lípides para a HDL. Trinta e nove hamsters Golden Syrian adultos machos receberam uma dieta hiperlipídica contendo 0,5% colesterol e 10% de óleo de coco (n=20, grupo dieta hiperlipídica) ou uma ração comercial usual (n=19, grupo controle) por 15 semanas. Os animais foram sacrificados e amostras de sangue foram coletadas para determinação do perfil lipídico, atividade da paroxonase 1 (PON1), da proteína de transferência de éster de colesterol (CETP) e da proteína de transferência de fosfolípides (PLTP), bem como a composição em lipídes da fração HDL. A transferência simultânea de colesterol livre (CL), éster de colesterol (EC), triglicérides (TG) e fosfolípides (FL) é baseada na troca de lípides ocorrida entre uma nanoemulsão lipídica artificial, marcada radioativamente com 14C-CL e 3H-TG ou 14C-FL e 3H-EC, e a HDL. Após precipitação química da nanoemulsão e das demais lipoproteínas, a capacidade da HDL em receber lípides foi quantificada pela medida da radioatividade presente na HDL. Além disso, a aorta e o fígado dos hamsters foram coletados para a determinação da composição em lípides e para análise histológica. Em relação ao perfil lipídico o colesterol total, HDL-C, n-HDL-C, FL, CL e EC foram maiores no grupo dieta hiperlipídica comparado ao grupo controle, já a concentração de TG não diferiu entre os grupos. A concentração de CL e EC da fração HDL foram maior no grupo dieta hiperlipídica. A transferência de 14C-CL, 3H-TG, 14C-FL e 3H-EC, bem como a atividade da CETP e da PLTP foram maiores no grupo dieta hiperlipídica. A atividade da PON1 não diferiu entre os grupos. A composição de CL da aorta foi maior no grupo dieta hiperlipídica comparado ao controle, no entanto o diâmetro interno e externo da aorta não diferiu entre os grupos. No grupo dieta hiperlipídica, a composição de EC, CL, TG e FL do fígado e o diâmetro dos hepatócitos foi maior do que no grupo controle. Dessa forma, a dieta hiperlipídica, i.e., enriquecida com colesterol e gordura saturada, em hamsters, modifica a composição em CL e EC da fração HDL, a sua capacidade em receber lípides, bem como outros aspectos relacionados ao seu metabolismo, o que pode alterar as propriedades antiaterogênicas da HDL. / High density lipoprotein (HDL) is known to protect against cardiovascular disease by removing the excess of cholesterol from peripheral tissues. However, other aspects of the HDL metabolism, as the transport of cholesterol of the other classes of lipoproteínas for the HDL should be sought to evaluate its protective action. Here, we tested the hypothesis whether a hyperlipidemic diet, in hamsters, alters the composition of the HDL fraction and ability of HDL to simultaneously receive lipids. Thirty-nine adult male Golden Syrian hamsters were fed hyperlipidemic diet containing 0.5% cholesterol and 10% coconut oil (n=20, hyperlipidemic diet group) or a regular chow diet (n=19, control group) for 15 wk. Then the animals were sacrificed and blood samples were collected for determination of plasma lipids, paraoxonase 1 (PON1), cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) activities, and lipids composition of the HDL fraction. Simultaneous transfer of phospholipids (PL), free cholesterol (FC), cholesteryl esters (CE) and triglycerides (TG) from an artificial lipidic nanoemulsion to HDL was performed in an in vitro assay, in which a nanoemulsion doubled labeled with either 14C-FC and 3H-TG or 14C-PL and 3H-CE was incubated with plasma and the radioactivity was counted in the HDL fraction after chemical precipitation. The aorta and the liver of the hamsters were collected for determination of the lipids composition and histological analysis. Plasma total cholesterol, HDL-C, n-HDL-C, CE, FC and PL were greater in the hyperlipidemic diet group than in the control group. However, TG levels were similar between the groups. Compared with the control group, the hyperlipidemic diet group had higher FC and CE in the HDL plasma fraction. Also, the transfer rates of 14C-FC, 3H-TG, 14C-PL and 3H-CE, CETP and PLTP were greater in the hyperlipidemic diet group compared with control group. PON1 activity was equal in both groups. The content of FC in the aorta tissue was greater in hyperlipidemic diet group, but the internal and external diameters of the aorta were equal in both groups. In hyperlipidemic diet group, the content of CE, FC, PL and TG in the liver and the diameter of the hepatocytes were greater than that measured in control group. The hyperlipidemic diet, i.e., dietary cholesterol and saturated fat, in hamsters, alters the FC and CE composition of the HDL fraction and lead to a disturbance in the ability of HDL to receive lipids. And consequently, may alter the antiatherogenic properties of this lipoprotein.

Background One of the challenges to public health in Sweden is the consumption of excessive saturated fat and too little unsaturated fat. The National Board of Health and Welfare (NBHW), the Swedish National Food Agency (SNFA) and the health sector work together to tackle such challenges, through educating the public on healthy dietary habits. The SNFA provides guidelines for all nutritional information but some of the guidelines have often been questioned leading to uncertainty and differing attitudes towards the consumption of fat in particular. Aims The study’s aim was to compare healthcare professionals’ attitudes to dietary fat and fat consumption to those of non-health professionals. A further aim was to assess if the named two groups gave advice on dietary habits. Method An online questionnaire survey was carried out with the participation of 260 adults recruited through convenience sampling. The questionnaire comprised 13 questions and the data collected were compiled in Microsoft Excel then imported to IBM SPSS 20.0., for processing and analysis. Results were analyzed using chi-square tests with p<0.05. Results A total of 73 healthcare professionals and 187 non-health professionals took part in the study.  Significantly more healthcare professionals than non-health professionals knew and were positive to established dietary advice regarding fat. There were however no differences between the two groups in the consumption of hard dietary fats. Both groups gave advice on dietary habits. Conclusions Healthcare professionals can be perceived as more knowledgeable than non-health professionals on fat consumption. The sharing of dietary advice by healthcare professionals may therefore lead to positive developments regarding those dietary guidelines that have often been questioned. This however requires that the healthcare professionals act professionally and separate what they do in private from what they advise their patients. / Bakgrund En av utmaningarna för folkhälsan i Sverige är konsumtion av för mycket mättat fett och för lite omättat fett.  Socialstyrelsen, det svenska Livsmedelsverket (SLV) och hälsosektorn arbeta tillsammans för att hantera utmaningen genom att utbilda allmänheten om goda matvanor. SLV ger riktlinjer för all näringsinformation men vissa av dessa har ifrågasatts vilket leder till osäkerhet och varierande inställning till just fett och dess konsumtion. Syfte Studiens syfte var att studera attityder till fett och fettkonsumtion bland hälso- och sjukvårdspersonal och icke-vårdpersonal.  Ytterligare syfte var att se om de två grupperna gav råd om matvanor. Metod En webbaserad enkätundersökning genomfördes med deltagandet av 260 vuxna som rekryterades genom bekvämlighetsurval. Enkäten bestod av 13 frågor.  Data som samlades in sammanställdes i Microsoft Excel och fördes sedan över till IBM SPSS 20.0 för bearbetning och analys. Resultaten analyserades genom att använda chi-två test med p < 0,05. Resultat Totalt deltog 73 hälso- och sjukvårdspersonal och 187 icke-vårdpersonal i studien. Betydligt fler hälso- och sjukvårdspersonal än icke-vårdpersonal visste om och var positiva till etablerade kostråd om fett. Det fanns dock inga skillnader mellan de två grupperna i konsumtionen av hårda fetter i kosten. Båda grupperna gav råd om matvanor. Slutsatser Hälso- och sjukvårdspersonal kan upplevas som mer kunniga än icke-vårdpersonal angående fettkonsumtion. Råden om matvanor från hälso- och sjukvårdspersonal kan därför leda till positiv utveckling när det gäller de kostråd som ofta ifrågasätts. Detta kräver dock att hälso- och sjukvårdspersonalen agerar professionellt och separerar vad de gör privat och råd de ger till patienter.

The Female Athlete Triad, consisting of the interrelated conditions of low energy availability, leading to menstrual disturbances and low bone mineral density, is commonly diagnosed amongst excessively exercising women. The American College of Sports Medicine emphasizes that the underlying factor of the Triad is a discrepancy between dietary energy intake and the energy requirements needed to support high levels of physical activity in addition to other homeostatic and physiological bodily processes. Although low energy availability is largely recognized as a causative factor for amenorrhea and low bone density, no studies to date have examined specific macro- and micro-nutrient intake relating to bone mineral density in the female athlete population. The hypothesis to be tested was that a difference in the intake of specific nutrients between athletes with menstrual disturbances (amenorrheic) and regularly menstruating (eumenorrheic) athletes contributes to low bone mineral density in female athletes exhibiting symptoms of the Triad. Methods: 4-day food records were collected from 118 females, ages 14-23 years, who exhibited weight within the normal range. 68 participants were amenorrheic athletes (AA), 24 participants were eumenorrheic athletes (EUM), and 26 participants were non-exercising females within the same age group (non-athletes: NA). Serum levels of vitamin D, phosphorus, calcium, and estradiol were also collected. Results: In contrast to previous studies, there was no difference in energy availability between the AA, EUM, and NA groups. The groups did differ in their intake of several macro-and micro-nutrients, and many of these nutrients correlated significantly with lumbar spine BMD. In a multivariate model that included vegetable and total proteins, soluble, insoluble and total dietary fiber, pectins, phytic acid, natural folate, calcium intake, vitamin D intake, serum vitamin D levels, and % calories from saturated fatty acids (SFA), only dietary fiber remained negatively associated and % calories from SFA positively associated with lumbar spine BMD. Conclusions: Dietary fiber has a significant inverse association and % calories from SFA a positive association with lumbar spine BMD, even after controlling for other nutrient intake and serum levels and intake of Vitamin D and calcium. Therefore, fiber and saturated fat may exert effects unrelated to vitamin D status and overall energy availability to impact bone density. Nutrition guidelines for female athlete triad patients need to be reassessed.

A lipoproteína de alta densidade (HDL) tem várias ações protetoras contra o desenvolvimento de doenças cardiovasculares, como remover o excesso de colesterol dos tecidos periféricos. No entanto, outros aspectos do metabolismo da HDL, como o transporte de colesterol das outras classes de lipoproteínas para a HDL devem ser avaliados para verificar a sua ação protetora. Sendo assim, nosso objetivo foi verificar, em hamsters, se a dieta hiperlipídica altera fatores relacionados ao metabolismo da HDL, tais como a composição da fração HDL e a transferência simultânea de lípides para a HDL. Trinta e nove hamsters Golden Syrian adultos machos receberam uma dieta hiperlipídica contendo 0,5% colesterol e 10% de óleo de coco (n=20, grupo dieta hiperlipídica) ou uma ração comercial usual (n=19, grupo controle) por 15 semanas. Os animais foram sacrificados e amostras de sangue foram coletadas para determinação do perfil lipídico, atividade da paroxonase 1 (PON1), da proteína de transferência de éster de colesterol (CETP) e da proteína de transferência de fosfolípides (PLTP), bem como a composição em lipídes da fração HDL. A transferência simultânea de colesterol livre (CL), éster de colesterol (EC), triglicérides (TG) e fosfolípides (FL) é baseada na troca de lípides ocorrida entre uma nanoemulsão lipídica artificial, marcada radioativamente com 14C-CL e 3H-TG ou 14C-FL e 3H-EC, e a HDL. Após precipitação química da nanoemulsão e das demais lipoproteínas, a capacidade da HDL em receber lípides foi quantificada pela medida da radioatividade presente na HDL. Além disso, a aorta e o fígado dos hamsters foram coletados para a determinação da composição em lípides e para análise histológica. Em relação ao perfil lipídico o colesterol total, HDL-C, n-HDL-C, FL, CL e EC foram maiores no grupo dieta hiperlipídica comparado ao grupo controle, já a concentração de TG não diferiu entre os grupos. A concentração de CL e EC da fração HDL foram maior no grupo dieta hiperlipídica. A transferência de 14C-CL, 3H-TG, 14C-FL e 3H-EC, bem como a atividade da CETP e da PLTP foram maiores no grupo dieta hiperlipídica. A atividade da PON1 não diferiu entre os grupos. A composição de CL da aorta foi maior no grupo dieta hiperlipídica comparado ao controle, no entanto o diâmetro interno e externo da aorta não diferiu entre os grupos. No grupo dieta hiperlipídica, a composição de EC, CL, TG e FL do fígado e o diâmetro dos hepatócitos foi maior do que no grupo controle. Dessa forma, a dieta hiperlipídica, i.e., enriquecida com colesterol e gordura saturada, em hamsters, modifica a composição em CL e EC da fração HDL, a sua capacidade em receber lípides, bem como outros aspectos relacionados ao seu metabolismo, o que pode alterar as propriedades antiaterogênicas da HDL. / High density lipoprotein (HDL) is known to protect against cardiovascular disease by removing the excess of cholesterol from peripheral tissues. However, other aspects of the HDL metabolism, as the transport of cholesterol of the other classes of lipoproteínas for the HDL should be sought to evaluate its protective action. Here, we tested the hypothesis whether a hyperlipidemic diet, in hamsters, alters the composition of the HDL fraction and ability of HDL to simultaneously receive lipids. Thirty-nine adult male Golden Syrian hamsters were fed hyperlipidemic diet containing 0.5% cholesterol and 10% coconut oil (n=20, hyperlipidemic diet group) or a regular chow diet (n=19, control group) for 15 wk. Then the animals were sacrificed and blood samples were collected for determination of plasma lipids, paraoxonase 1 (PON1), cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) activities, and lipids composition of the HDL fraction. Simultaneous transfer of phospholipids (PL), free cholesterol (FC), cholesteryl esters (CE) and triglycerides (TG) from an artificial lipidic nanoemulsion to HDL was performed in an in vitro assay, in which a nanoemulsion doubled labeled with either 14C-FC and 3H-TG or 14C-PL and 3H-CE was incubated with plasma and the radioactivity was counted in the HDL fraction after chemical precipitation. The aorta and the liver of the hamsters were collected for determination of the lipids composition and histological analysis. Plasma total cholesterol, HDL-C, n-HDL-C, CE, FC and PL were greater in the hyperlipidemic diet group than in the control group. However, TG levels were similar between the groups. Compared with the control group, the hyperlipidemic diet group had higher FC and CE in the HDL plasma fraction. Also, the transfer rates of 14C-FC, 3H-TG, 14C-PL and 3H-CE, CETP and PLTP were greater in the hyperlipidemic diet group compared with control group. PON1 activity was equal in both groups. The content of FC in the aorta tissue was greater in hyperlipidemic diet group, but the internal and external diameters of the aorta were equal in both groups. In hyperlipidemic diet group, the content of CE, FC, PL and TG in the liver and the diameter of the hepatocytes were greater than that measured in control group. The hyperlipidemic diet, i.e., dietary cholesterol and saturated fat, in hamsters, alters the FC and CE composition of the HDL fraction and lead to a disturbance in the ability of HDL to receive lipids. And consequently, may alter the antiatherogenic properties of this lipoprotein.