Controversies and discrepancies in the effect of dietary fat and cholesterol on cardiovascular risk

Cardiovascular disease (CVD) is the leading cause of death worldwide. The top ten causes of death in Singapore include many cardiovascular-related diseases such as ischaemic heart disease. The increasing prevalence of CVD poses a burden to both the economy and healthcare system of a country. Dietary habits, in particular dietary fats and cholesterol intake, have been shown to greatly influence CVD risks. Therefore, reference and adherence to relevant dietary guidelines could be crucial in CVD prevention. Recent research findings have provided novel insights into the relationship between certain dietary fats or cholesterol intake and CVD risks, challenging or reinforcing previous guidelines. These findings may, however, be conflicting, and there are still controversies over the effects of dietary fats and cholesterol as well as their association with cardiovascular risk. This review paper aims to evaluate common controversies, identify gaps in relevant research areas and summarise evidence-based dietary recommendations.

Estado del arte del gusto graso / State of the Art of "Fat Flavor"

Resumen Antecedentes: existe evidencia científica sobre la detección y reconocimiento del sabor a grasa en las papilas gustativas, y sobre la relación entre las propiedades sensoriales de los lípidos en los alimentos, la nutrición y la salud pública. Objetivo: presentar los avances investigativos en la cualidad del sabor a grasa y las estrategias actuales para lograr el cumplimiento de las recomen daciones del consumo de lípidos. Resultados: existen bases fisiológicas para afirmar que el sabor graso constituye uno de los gustos básicos, en los que están identificados sus posibles receptores y polimorfismos. La sensibilidad de estos receptores a los ácidos grasos se afecta por el consumo de grasa. La grasa dietaria se puede reducir cambiando los métodos de cocción y en la industria alimentaria usando reemplazantes de grasa. Conclusión: el gusto graso podría estar modulado por factores genéticos y ambientales. Existen variantes genéticas de los receptores y su sensibili dad depende de la grasa dietaria. Los reemplazantes de grasa son una alternativa para reducir su aporte alimentario.

Abstract Background: Scientific evidence exists on the detection and recognition of the'fatty taste' as one of the tastes sensed by taste buds, and around the sensory properties of fats in foods as related to nutrition and public health. Objective: Present research advances in the quality of the fatty flavor and current strategies to achieve compliance with the recommendations for lipid consumption. Results: There is physiological basis for affirming that the fatty taste constitutes one of the basic tastes, in which its possible receptors and polymorphisms are identified. Taste sensitivity to fatty acids is affected by the consumption of lipids. Dietary fat consumption can be reduced by changing cooking methods and in the food industry by using fat replacers. Conclusion: The fatty taste could be modulated by genetic and environmental factors. Genetic variants exist in taste receptors and their sensitivity depends on dietary fat consumption. Fat replacers are an alternative to help reduce dietary intake.

Contenido de grasa saturada y trans en panes de panaderías de la ciudad de Medellín, Colombia / Saturated and trans fat content in the breads of bakeries in Medellín, Colombia

ANTECEDENTES: Se desconoce el contenido de grasas saturada (GS) y trans (Gtrans) en panes sin etiqueta y sin vigilancia por entidad regulatoria de Colombia. PROPÓSITO: Comparar el contenido de GS y Gtrans en panes de algunas panaderías de Medellín con lo reglamentado: 0,5 g/50 g de pan, para ambos tipos de grasa según resolución 2508 de 2012 del Ministerio de Salud. MATERIALES Y MÉTODOS: Se muestrearon 45 panes de tres tipos (aliñado, leche y croissant) en tres niveles socioeconómicos (NSE) según ubicación de la panadería. Se cuantificó grasa total gravimétricamente y GS y Gtrans por cromatografía de gases. RESULTADOS: El porcentaje de GS y Gtrans con respecto a la grasa total extraíble fue 43,8% y 0,6% en pan aliñado, 37,4% y 0,6% en pan leche y 32,2% y 0,9% en pan croissant, sin diferencia significativa entre ellos (p= 0,155 y 0,184, respectivamente). CONCLUSIONES: Comparado con la resolución 2508, el contenido de GS fue mayor al límite establecido en resolución y el contenido de Gtrans fue menor en pan aliñado, leche o croissant. Los panes evaluados en las panaderías del NSE bajo contenían mayor Gtrans que los otros.

BACKGROUND: The content of saturated (GS) and trans (Gtrans) fats in unlabeled and breads that are not regulated by the Colombian government is unknown. PURPOSE: To compare the content of GS and Gtrans in breads of bakeries in Medellín with the following regulation: 0.5 g/50 g of bread, for both types of fat according to the 2012 Ministry of Health resolution #2508. MATERIALS AND METHODS: 45 breads of three types (seasoned, milk and croissant) were sampled at bakeries from three socioeconomic levels (NSE) according to the location. Total fat was quantified gravimetrically and GS and Gtrans by gas chromatography. RESULTS: The percentage of GS and Gtrans with respect to the total extractable fat was 43.8% and 0.6% in seasoned bread, 37.4% and 0.6% in milk bread and 32.2% and 0.9% in croissant bread, with no significant difference by bread type (p= 0.155 and 0.184, respectively). CONCLUSIONS: GS content of sampled breadswas greater than the limit established in the resolution. Gtrans content was lower in seasoned bread andmilk bread compared to croissant. The breads evaluated in the bakeries of lower NSE contained higher Gtrans than the others.

Composición química y calidad de la grasa contenida en frituras de maíz elaboradas y consumidas en Navojoa, estado de Sonora, México / Chemical Composition and Fat Quality in Fried Foods Made with Corn that Are Prepared and Consumed in Navojoa, State of Sonora, Mexico

Antecedentes: el consumo de frituras en México es alto, aunque las grasas se asocian con enfermedades crónicas no transmisibles. Objetivo: evaluar la composición química y calidad de la grasa obtenida de churros fritos de maíz elaborados y consumidos en Navojoa, estado de Sonora, México. Materiales y métodos: a cuatro muestras obtenidas en establecimientos comerciales se les realizó análisis químico proximal y determinación de índices de calidad de la grasa (acidez, peróxidos, yodo y anisidina), según normas mexicanas. Resultados: el aporte nutricional de las muestras estuvo en los siguientes rangos expresados en g %: grasas (23,7±0,2 y 35,2±1,0 g %), proteínas (2,5±0,0 y 8,1±1,4 g %), carbohidratos (54,1±0,3 y 64,40±0,5 g %) y energía (485±3 y 531±1 kcal %) con diferencias entre ellas (p<0,05). El mayor contenido de grasa y energía lo presentó B2 y el mejor perfil nutricional B4. La muestra B1 superó los límites máximos permitidos de acidez (4,8) y de peroxidación (10,6) con diferencias respecto a las otras muestras (p<0,05). Conclusiones: la densidad energética de los churros de maíz analizados es alta (superior a 4 kcal/g) al igual que el aporte de grasas, especialmente en la muestra B2. B4 presenta el mejor perfil nutricional y B1 el mayor deterioro oxidativo.

Background: Consumption of fried foods in Mexico is high, even though fats in fried foods are associated with noncommunicable chronic diseases. Objective: Evaluate the chemical composition and fat quality obtained from fried corn churros prepared and consumed in Navojoa, state of Sonora, Mexico. Materials and Methods: Four samples obtained from commercial establishments were subjected to proximal chemical analysis and determination of fat quality indices (acidity, alkalinity, iodine and anisidine), according to Mexican standards. Results: The nutritional breakdown of the samples is shown in the following ranges, expressed as grams % (g %): fats (23.7 ± 0.2 and 35.2 ± 1.0 g %), proteins (2.5 ± 0.0 and 8.1 ± 1.4 g %), carbohydrates (54.1 ± 0.3 and 64.4 ± 0.5 g %), and energy (kcal) (485 ± 3 and 531 ± 1) with significant differences between samples (p<0.05). The highest fat and energy content was presented by sample B2 and the best nutritional profile by sample B4. Sample B1 exceeded the maximum limits of acidity (4.8) and alkalinity (10.6) with a significant inter-sample difference (p <0.05). Conclusion: The energy density of the sampled fried corn churros is high (above 4 kcal/gram), as well as the fat content, especially in sample B2. Sample B4 presents the best nutrition profile and sample B1 the greatest oxidative deterioration.

Dietary inflammatory index is associated with serum C-reactive protein and protein energy wasting in hemodialysis patients: A cross-sectional study

BACKGROUND/OBJECTIVE: Malnutrition and inflammation are reported as the most powerful predictors of mortality and morbidity in hemodialysis (HD) patients. Diet has a key role in modulating inflammation and dietary inflammatory index (DII) is a new tool for assessment of inflammatory potential of diet. The aim of this study was to evaluate the application of DII on dietary intake of HD patients and examine the associations between DII and malnutrition-inflammation markers. SUBJECTS/METHODS: A total of 105 subjects were recruited for this cross-sectional study. Anthropometric measurements, 3-day dietary recall, and pre-dialysis biochemical parameters were recorded for each subject. Subjective global assessment (SGA), which was previously validated for HD patients, and malnutrition inflammation score (MIS) were used for the diagnosis of protein energy wasting. DII was calculated according to average of 3-day dietary recall data. RESULTS: DII showed significant correlation with reliable malnutrition and inflammation indicators including SGA (r = 0.28, P < 0.01), MIS (r = 0.28, P < 0.01), and serum C-reactive protein (CRP) (r = 0.35, P < 0.001) in HD patients. When the study population was divided into three subgroups according to their DII score, significant increasing trends across the tertiles of DII were observed for SGA score (P = 0.035), serum CRP (P = 0.001), dietary energy (P < 0.001), total fat (P < 0.001), saturated fatty acids (P < 0.001), polyunsaturated fatty acids (P = 0.006), and omega-6 fatty acids (P = 0.01) intakes. CONCLUSION: This study shows that DII is a good tool for assessing the overall inflammatory potential of diet in HD patients.

Dietary Fat Intake, Serum Estrogen Level and Obesity as Risk Factors of Breast Cancer in Saudi Females: A Case-Control Study.

Aims: The aim of our study was to examine the associations of dietary fat intake, serum estrogen level and obesity with the risk of breast cancer in a case-control study among Saudi females including newly diagnosed breast cancer patients. Study Design: Case-control study. Place and Duration of Study: King Abdulaziz Medical City, Riyadh, Saudi Arabia, during the period between 1st February and 30th May, 2008 Methodology: Dietary histories were collected 40 newly diagnosed female breast cancer cases and 82 randomly selected control subjects matched for age, parity, gravidity, number of children, breast feeding practice and age at marriage. A modified food frequency questionnaire (FFQ).was applied. Anthropometric measurements and blood tests that measured LDL, HDL, triglycerides (TGs) and estrogen levels were performed. Significance was considered at P≤0.05. Results: Breast cancer was significantly associated with overall obesity based on BMI (OR = 3.10, 95%, CI = 1.17–8.25, P=0.02) and central obesity based on WC (OR = 3.95, 95%, CI = 1.27–12.28, P=0.01). Cases exhibited significantly higher fat mass (39.6 vs. 36.9 kg, p=0.04) and significantly lower Fat intake (46.0±27.5 vs 59.0±38.9 g/day, P=0.034) than did the control group. The mean levels of TGs (2.9±1.1vs.1.8±1.1 mmol/L, P<0.0001) and estradiol (131.0 vs 70.6 pmol/L, P≤0.008) were significantly higher in the study patients compared with the control subjects, whereas the mean level of low density lipoprotein (LDL-C) was significantly higher in the control subjects (3.1±0.8 vs. 1.6±1.0 mmol/L, P≤0.0001) compared with the study patients. Conclusion: Both overall obesity and central obesity were significantly associated with breast cancer. Higher fat mass and lower fat intake and increased estrogen level were significantly associated with breast cancer cases. Further prospective studies on the Saudi population are recommended to explore the mechanisms of these findings.

Etiopatogenia de la obesidad / Etiopathogenesis of obesity

La investigación de los factores etiopatogénicos de la obesidad, sean estos ambientales o genéticos, ha influido fuertemente en el desarrollo de las estrategias para controlar la enfermedad. Se considera a la obesidad como una enfermedad en la cual confluyen factores genéticos y ambientales, pero no se han dilucidado cabalmente los mecanismos de regulación del balance energético, cuyas alteraciones favorecen el incremento de la adiposidad en humanos. Entre los factores ambientales, además de la alimentación alta en calorías y el sedentarismo, se describen factores predisponentes sociales, culturales y familiares, así como situaciones o etapas fisiológicas de la vida que pueden gatillar aumento de peso. Aunque los factores y patologías genéticas se pueden evidenciar en un bajo porcentaje de los sujetos obesos, la predisposición genética a la obesidad se puede expresar a través de algunas características metabólicas, como un bajo gasto energético de reposo, mala oxidación de grasas o un bajo nivel de actividad física espontánea.

The investigation of the etiological factors of obesity, whether genetic or environmental, has strongly influenced the development of strategies to control the disease. Obesity must be considered as a disease in which genetic and environmental factors converge. However, the mechanisms of regulation of the energy balance, which changes favoring increased adiposity in humans, are not fully elucidated. Among environmental factors, in addition to high-calorie diet and sedentary lifestyle, it has been described social, cultural and family predisposing factors, as well as physiological conditions or stages of life that can trigger weight gain. Although genetic factors and pathologies can be evidenced in a low percentage of obese subjects, genetic predisposition to obesity can be expressed through some metabolic characteristics such as low metabolic rate, poor oxidation of fats or a low level of spontaneous physical activity.

Effect of carnitine supplementation on mitochondrial enzymes in liver and skeletal muscle of rat after dietary lipid manipulation and physical activity.

Effect of carnitine supplementation in enhancing fat utilization was investigated by looking into its effects on mitochondrial respiratory enzymes activity in liver and muscle as well as on membrane fatty acid profile in rats fed with hydrogenated fat (HF) and MUFA-rich peanut oil (PO) with or without exercise. Male Wistar rats were fed HF-diet (4 groups, 8 rats in each group) or PO-diet (4 groups, 8 rats in each group), with or without carnitine for 24 weeks. One group for each diet acted as sedentary control while the other groups were allowed swimming for 1 hr a day, 6 days/week, for 24 weeks. The PO diet as well as exercise increased the activities of mitochondrial enzymes, NADH dehydrogenase, NADH oxidase, cytochrome C reductase, cytochrome oxidase, while carnitine supplementation further augmented the oxidative capacity of both liver and muscle significantly by enhancing the activity of carnitine palmitoyl transferase and the respiratory chain enzymes. These effects can be attributed to the enhanced unsaturated fatty acids in phospholipids of mitochondria and may be due to increased fluidity of the membrane in these rats. Results of this study show a significant health promoting effects of carnitine supplementation which could be further augmented by regular exercise.

Effect of Leucine Intake on Body Weight Reduction in Rats Fed High Fat Diet

The principal objective of this study was to determine the effects of leucine on body weight reduction in high fat diet-induced overweight rats. To induce overweight, six-month-old male Sprague-Dawley rats (n = 80) were divided into 8 groups; one group of 10 rats was fed on a normal fat diet and the remaining 70 rats were fed on a high-fat diet (40% of energy as fat) for 14 weeks. Then, 10 rats fed on the normal fat diet and another 10 rats fed on the high fat diet were sacrificed to identify overweight induction. The remaining 60 rats were divided randomly into 6 groups according to body weight and fed on one of the diets with different dietary fat levels (9.6% or 40% of energy as fat) and leucine levels (0, 0.6 or 1.2 g/kg BW) for the following 5 weeks of experiments. The body weight loss in the Leu-administered groups (0.6 g, 1.2 g/kg BW) was significantly higher than those of Leu non-administered groups. The perirenal fat pad weights in the Leu-administered groups were significantly lower than those of the Leu non-administered groups. Of the hepatic enzymes, glucose-6-phosphate dehydrogenase (G6PDH) activities were reduced significantly in the Leu-administered groups than in the Leu non-administered groups. With the oral glucose tolerance test (OGTT), the incremental areas under the curve of the glucose response (IAUC) of the Leu-administered groups were significantly lower than those of the Leu non-administered groups. The fasting glucose concentration and HOMA-IR of the Leu-administered groups were significantly lower than those of the Leu non-administered groups. In conclusion, the results of this study suggest that one of the possible mechanisms of leucine in the observed body weight reduction might involve the inhibition of lipogenic enzyme activities such as glucose-6-phosphate dehydrogenase, rather than the activation of lipolysis enzymes. Additionally, leucine adminstration resulted in improved glucose metabolism.

Relation of Dietary Fat Intake Perception to Nutritional Status and Psychosocial Factors

Excess dietary fat intake is associated with many chronic diseases. This crosssectional study determines the differences in nutritional status and diet-related psychosocial factors by accuracy levels of dietary fat intake perceptions among adults. A total of 202 Universiti Putra Malaysia staff (20-55 years old) volunteered to participate in the study. Dietary fat accuracy levels (under-estimate, accurate and over-estimate) were determined by assessing actual fat intake through 24-hour diet recall and self-rated fat intake. Diet-related psychosocial factors assessed were perceived risks, intention to change, outcome expectancies and perceived barriers. About half (49.5%) of the respondents were classified as accurate estimators, while 35.6% and 14.9% were under-estimators and over-estimators, respectively. Dietary fat intake differed significantly between the dietary fat accuracy groups with under-estimators having the highest amount of dietary fat intake (F=17.10; p<0.001) and percentage of fat calories (F=103.99 + 0.533%, p<0.001). Over-estimators had the highest mean BMI (F=3.11, p<0.05) compared to other groups. Among the fat accuracy groups, under-estimators reported the least barriers to eating low fat foods (F= 3.671, p<0.05). There were no significant differences in waist circumference, energy intake, perceived disease risks, intention to change and outcome expectancies among the dietary fat accuracy groups. These findings suggest that inaccurate perceptions of dietary fat intake should not be overlooked as one of the cognitive barriers to dietary change and factors that influence nutritional status among adults.

A Study on the Fat and Fatty Acid Intake of College Women Evaluated through Internet Nutritional Assessment System

The purpose of this study was to investigate dietary fat and individual fatty acids intake pattern of 174 college women living in Seoul and Gyong-gi province through internet nutritional assessment system. Each of the subjects was required to input their own food intake for three days, which included two days during the week and one day of the weekend, on the web program directly and all of the data collected were used for statistical analysis. The mean daily caloric intake of the subjects was 1,500.9 kcal which was at 71.5% of Estimated Energy Requirement (EER ). Dietary fat contributed 27.6% of the total caloric intake which was slightly higher than the recommended limit of 25%. Daily cholesterol intake was 310.0 mg, which was also high to some degree. Mean daily N6 and N3 fatty acid intake was 6.1 g and 0.9 g, respectively, and calory % calculated from each were 3.63% and 0.53%. This result showed the intake of N3 fatty acid fell in Acceptable Macronutrient Distribution Ranges (AMDR )0.5 ~1.0% but that of N6 fatty acid was somewhat lower than the AMDR 4 ~8%. N6/N3 ratio 8.5/1, however, was within the desirable range 4 ~10/1. Considering overall dietary fatty acids intake, oleic acid was the most abundant, followed by linoleic and palmitic acid. And among polyunsaturated fatty acids intake, linoleic acid was exclusively high, accounting for 97.4% of total N6 fatty acid intake. On the contrary, three fatty acids, linolenic (67.3%), DHA (21.1%)and EPA (10.0%), together supplied 98.4% of total N3 fatty acid intake. Mean P/M/S was 0.9/1.1/1.0. The subjects' intake of fat, many fatty acids and cholesterol came from diverse food groups including meats, fats and oils, milk and milk products, eggs, fish, and soybean products. Nevertheless, the subjects tended to show unfavorable fat and fatty acids intake pattern in terms of quantity and quality. Based on these results, it is important to monitor dietary fat intake pattern of the general population continuously and an internet program such as the one used for this study would be valuable, especially for assessing dietary patterns in the younger generation.

Effect of dietary soluble fiber on neurohormonal profiles in serum and brain of rats

This study was conducted to investigate the effect of dietary soluble fiber administration and /or high fat diet on serum and brain neurohormonal profiles, adipose tissue mass and body weight gain in Sprague-Dawley rats. Four groups of rats were respectively fed 10% fat diet (C), 10% fat plus pectin diet (P), 20% fat diet (HFC) and 20% fat plus pectin diet (HFP) for 4 weeks. In HFP group, the food and energy intake, body weight gain, FER including fecal excretion were the smallest (p<0.05). Serum HDL-cholesterol, triglyceride and glucose level were also the lowest in HFP group (p<0.05). The weight of brain, epididymal fat pad and adrenal gland except liver didn't show any significant differences among groups. Interestingly serum norepinephrine concentration of HFP group tended to be higher, but dopamine concentration tended to be lower than those of HFC group. However serum catecholamine concentration didn't show any significant differences among all groups. Norepinephrine and epinephrine contents of right portion of midbrain of P and HFP groups were remarkably lower than those of the C group. These results suggested that soluble fiber pectin consumption might affect neurohormonal profiles in serum and brain according to dietary fat level.

Types and amount of dietary fat and colon cancer risk: Prevention by omega-3 fatty acid-rich diets

Colorectal cancer is the second most common malignancy in the Western world including the United Sates. In recent years there is a strong upward trend in colon cancer risk in Japan mainly due to Americanization of Japanese food habits. Several epidemiological studies point to a strong association between nutrient composition of the diet and cancer of the colon. The role of types of dietary fat, especially saturated fats of animal origin, n-6- and n-3-rich polyunsaturated fatty acids (PUFAs) in the etiology of colorectal cancer has become increasingly apparent. Epidemiological studies indicate a positive association between the dietary intake of saturated fat and/or animal fat and colon cancer risk and an inverse relationship between the intake of fish and fish oil rich in n-3 PUFAs and colon cancer development. Although the evidence from case-control studies and international correlational studies is not totally consistent, these inconsistencies may have arisen, at least in part, from methodological limitations. Animal, model studies have unequivocally provided evidence that the colon tumor-promoting effect of dietary fat depends on its fatty acid composition and that high dietary n-3 PUFAs lacks colon tumor-promoting effect, as compared to diets high in n-6 PUFAs or saturated fats. Diets rich in n-3 PUFAs inhibit colon carcinogenesis through the modulation of colonicras-p21, cyclooxygenase-2, and inducible nitric oxide synthase activities and apoptosis. Gene expression analysis using DNA microarrays indicates that n-3 fatty acid, docosahexaenoic acid activates cyclin-dependent kinase inhibitors such as p21, p27, p57 and p19 and inactivates antiapoptotic Bcl-2 family of genes, and prostagland in family of genes. These results suggest that decreasing the intake of n-6 PUFAs and saturated fats and increasing that of n-3 PUFAs, particularly eicosapentaenoic acid and docosahexaenoic acid has the potential to be a major component of colon cancer control.

The association between dietary fat and body fat in obese adults

BACKGROUND: There are different opinions on whether the percentage of dietary fat is associated with the development of obesity and on it's treatment . In this country, dietary fat intake has been smaller compared to the Western countries. The purpose of this study was to find whether intake of dietary fat is related to percentage body fat in obese adults cross sectionally. METHODS: Nutrient intake from 24 hour dietary recall and percent body fat from bioelectrical impedance method were measured in 51 obese adults. Total energy intake was associated with intake of dietary fat and body size. Thus, the association of intake of dietary fat and three types of fat with percentage body fat were examined after adjustment for total energy intake by using 4 statistical models (standard multivariate model, and nutrient residual model, energy partition model, and multivariate nutrient density model). RESULTS: In all of these models, the results for types of fat and total fat showed similar results. Higher intake of total fat, saturated and polyunsaturated fat was associated with increased percentage body fat, while higher intake of monounsaturated fat was associated with decreased percentage body fat. CONCLUSION: We found positive association between dietary intake of fat and percentage body fat in obese adults. Our results suggest that reducing fat intake would be a helpful way to prevent and treat obesity in adults.

A Butter Diet Induces Higher Levels of n-3 PUFA and of n-3/n-6 PUFA Ratio in Rat Serum and Hearts than a Safflower Oil Diet

The effects of a 47-week diet of butter of safflower oil as fat in combination with casein or soy protein as protein were observed for the serum concentrations of lipids and fatty acid compositions in rat serum and heart. Serum total cholesterol (Chol) did not differ among the four experimental diet groups. In the butter groups, significantly higher low-density lipoprotein (LDL)-Chol and lower high-density lipoprotein (HDL)-Chol were observed than in the safflower oil groups (p<0.005, respectively). Higher levels of α-tocopherol were found in the butter groups than in the safflower oil groups (p<0.05) and in the casein groups than in the soy protein groups (p<0.01). In comparison with the safflower oil groups, the butter groups showed higher n-3 polyunsaturated fatty acids (PUFA) contents and lower n-6 PUFA contents in serum and the hearts (p<0.005).The ratios of n-3/n-6 PUFA in the butter groups in serum, 0.26 and 0.18, and in the hearts, 0.37 and 0.36, (butter-casein diet and butter-soy protein diet, respectively) were higher than those of the safflower oil groups of under 0.01 in serum and 0.02 and 0.03 in the hearts (safflower oil-casein diet and safflower oil-soy protein diet, respectively) (p<0.005). In the soy protein groups, higher n-3 PUFA contents in the hearts were found than those of the casein groups (p<0.05). This study suggested that the butter diet induces higher levels of n-3 PUFA and a higher n-3/n-6 PUFA ratio than the safflower oil diet in rat serum and hearts over a long feeding period.

Effects of Dietary Fat on Lipid Peroxidation Level in Rats / 环境与健康杂志

Objective To explore the effects of dietary fat on lipid peroxidation in female F344 rats. Methods The rats were fed diets containing various levels of corn oil ( 3%, 5%, 10%, 15%, or 20% ) for 2, 10, 20 weeks and to detect the malondialdehyde (MDA) concentrations in cerebellum, kidney and liver tissues by HPLC method. Results It was observed that rats consuming 3% and 5% corn oil diets yielded significantly higher levels of MDA compared with those fed with higher fat diets. It was also observed that the MDA levels at group of 20 weeks of feeding were significantly lower than groups of 2 weeks and/or 10 weeks of feeding. The three organs studied showed different MDA levels. MDA level in cerebellum was obviously higher than that in liver and kidney. Conclusion The lipid peroxidation linking with dietary fat seems to have tissue specific and time specific. The cerebellum tissues seem easy to be attacked by lipid peroxidation linking with dietary fat. The peaks of MDA concentrations emerge were at 2 week time point in cerebellum and at 10 week time point in liver and kidney respectively.

The effect of dietary fats of immune response in sublethally irradiated rats

No abstract available.

Effect of dietary fats on immune response in rats

No abstract available.

EFFECT OF DIFFERENT DIETARY FAT ON GLUCOSE TOLERANCE AND INSULIN SENSITIVITY / 营养学报

Objective: To investigate the effects of different dietary fat on insulin sensitivity and glucose tolerance in rats. Methods: Fifty adult male Sprague-Dawley rats were randomly assigned to five groups and fed on basal diet (low fat diet) and four test diets containing 30.4% fat of total energy as lard, perilla oil, sunflower oil or olive oil respectively for 6 w. An oral glucose tolerance test (OGTT) was performed and blood samples were taken for measurement of serum insulin, triglyceride (TG) and total cholesterol (TC) level. Insulin sensitivity index (ISI) was calculated and epididymal fat pad was weighed. Results: In comparison with rats fed low fat, rats fed lard had a low ISI and a high serum glucose level 120 min after glucose load. The ISI in groups of sunflower oil and olive oil was markedly higher than in lard group, whereas serum glucose at 120 min was significantly lower. Serum glucose and insulin level both at 0 min and 120 min were significantly lower and ISI was higher in perilla oil group than that in lard group. Moreover, rats fed perilla oil had a low fasting glucose and a higher ISI compared with rats fed sunflower oil, olive oil and low fat respectively. Serum TC and TG were significantly lower in rats fed perilla oil than in rats fed low fat and lard respectively. Relative epididymal fat pad weight was lower in rats fed perilla oil than in rats fed lard. Conclusion: Perilla oil is effective in increasing insulin sensitivity and improving glucose metabolism in rats, and the effects of sunflower oil and olive oil are between that of perilla oil and lard. The hypoglycemic effect of perilla oil might be mediated, at least in part by reducing triglyceride level and body fat accumulation.

INVESTIGATION OF THE FATTY ACID COMPOSITIONS OF SERUM CHOLESTERYL ESTERS IN THE POPULATIONS OF SOME DISTRICTS AND NATIONALITIES IN CHINA / 营养学报

Fatty acid compositions of cholesteryl esters in 113 male adults of 4 nationalities in 5 districts in China were analyzed. Fatty acid patterns of cholesteryl esters in different population groups were similar, though some variations were observed which seemed to be caused by the difference in diet. The correlations of serum cholesteryl ester fatty acids with the quality and quantity of dietary fat and with the serum lipid levels were discussed.