Paradoxical effect of a pequi oil-rich diet on the development of atherosclerosis: balance between antioxidant and hyperlipidemic properties

Pequi is the fruit of Caryocar brasiliense and its oil has a high concentration of monounsaturated and saturated fatty acids, which are anti- and pro-atherogenic agents, respectively, and of carotenoids, which give it antioxidant properties. Our objective was to study the effect of the intake of a cholesterol-rich diet supplemented with pequi oil, compared to the same diet containing soybean oil, on atherosclerosis development, and oxidative stress in atherosclerosis-susceptible LDL receptor-deficient mice (LDLr-/-, C57BL/6-background). Female mice were fed a cholesterol-rich diet containing 7% soybean oil (Soybean group, N = 12) or 7% pequi oil (Pequi group, N = 12) for 6 weeks. The Pequi group presented a more atherogenic lipid profile and more advanced atherosclerotic lesions in the aortic root compared to the Soybean group. However, the Pequi group presented a less advanced lesion in the aorta than the Soybean group and showed lower lipid peroxidation (Soybean group: 50.2 ± 7.1; Pequi group: 30.0 ± 4.8 µmol MDA/mg protein) and anti-oxidized LDL autoantibodies (Soybean group: 35.7 ± 9.4; Pequi group: 15.6 ± 3.7 arbitrary units). Peritoneal macrophages from the Pequi group stimulated with zymosan showed a reduction in the release of reactive oxygen species compared to the Soybean group. Our data suggest that a pequi oil-rich diet slows atherogenesis in the initial stages, possibly due to its antioxidant activity. However, the increase of serum cholesterol induces a more prominent LDL migration toward the intimae of arteries, increasing the advanced atherosclerotic plaque. In conclusion, pequi oil associated with an atherogenic diet worsens the lipid profile and accelerates the formation of advanced atherosclerotic lesions despite its antioxidant action.

Hepatic and biochemical repercussions of a polyunsaturated fat-rich hypercaloric and hyperlipidic diet in Wistar rats / Repercussões hepáticas e bioquímicas da dieta hipercalórica e hiperlipídica rica em gordura poliinsaturada em ratos Wistar

CONTEXT: Non-alcoholic fatty liver disease is characterized by lipid deposits in the hepatocytes and has been associated with obesity, dyslipidemia and type-2 diabetes. It is considered a hepatic manifestation of the metabolic syndrome, of which the main component is insulin resistance leading to hyperinsulinemia and increased production of inflammatory cytokines. Saturated fat promotes hypertriglyceridemia and hyperinsulinemia, reduces levels of high-density cholesterol and increases levels of low-density cholesterol, while polyunsaturated fat is associated with hypolipidemic, antiinflammatory and imunoregulating action. OBJECTIVE: To evaluate the hepatic and biochemical repercussions of a polyunsaturated fat-rich diet in Wistar rats. METHODS: Twenty-two rats were distributed equally in two groups: GI - standard diet (Biobase Bio-tec Ratos e Camundongos®) providing 3.000 kcal/kg and GII - hypercaloric and hyperlipidic diet providing 4.250 kcal/kg (ω-6:ω-3 = 3:1). The animals were euthanized after 23 weeks of experiment. The weight, biochemical parameters and hepatohistological changes were registered. RESULTS: Findings were submitted to variance analysis with the level of statistical significance at 5 percent. The average weight did not differ significantly between the groups at baseline (P = 0.711), but was greater in Group II by the end of the experiment (P = 0.000). The levels of triglycerides (P = 0.039), total cholesterol (P = 0.015) and HDL (P = 0.005) were higher in Group I than in Group II. Macrovesicular steatosis was significantly more common in Group II than in Group I (P = 0.03). CONCLUSION: Hypercaloric and hyperlipidic diet rich in polyunsaturated fat promotes weight gain and favors the development of hepatic steatosis while reducing serum levels of triglycerides, total cholesterol and HDL.

CONTEXTO: A doença hepática gordurosa não-alcoólica caracteriza-se por depósito de lipídios nos hepatócitos. Desperta grande interesse por sua associação com obesidade, dislipidemias e diabetes mellitus tipo 2. É considerada a manifestação hepática da síndrome metabólica, cujo principal componente é a resistência à insulina, com consequente hiperinsulinemia e produção aumentada de citocinas inflamatórias. Dietas ricas em gorduras saturadas promovem hipertrigliceridemia, diminuição do colesterol de alta densidade, aumento do colesterol de baixa densidade e hiperinsulinemia, enquanto dietas ricas em gordura poliinsaturada podem apresentar efeitos hipolipidêmicos, antiinflamatórios e imunorreguladores. OBJETIVO: Investigar as repercussões hepáticas e bioquímicas da dieta rica em gordura poliinsaturada em ratos Wistar. MÉTODOS: Os animais (22) foram distribuidos nos grupos GI-dieta padrao (Biobase Bio-tec Ratos e Camundongos®) com 3000 kcal/kg e GII-dieta hipercalorica e hiperlipidica, com 4250 kcal/kg, relação ω-6: ω-3 = 3:1. Foram mortos apos 23 semanas de administração das dietas. Avaliaram-se peso, exames bioquimicos e alteracoes histológicas do fígado. RESULTADOS: Foram utilizados testes de análise de variância com nível de significância de 5 por cento (P<0,05). Não houve diferença significante na média de peso entre os grupos (P = 0,711) no início, entretanto GII apresentou maior média que GI ao final do experimento (P = 0,000). GI mostrou níveis significantemente mais elevados de triglicerídeos (P = 0,03), colesterol total (P = 0,039) e HDL (P = 0,015) do que GII. O GII apresentou maior média de esteatose macrovesicular do que GI (P = 0,005). CONCLUSÃO: A dieta hipercalórica e hiperlipídica, rica em gordura poliinsaturada, promove esteatose hepática e incremento de peso, contudo reduz os níveis séricos de triglicerídeos, colesterol total e HDL.

Association between dietary fat and breast cancer in Puerto Rican postmenopausal women attending a breast cancer clinic

OBJECTIVE: A pilot case-control study was conducted to examine the possible association between dietary fat intake and the development of postmenopausal breast cancer. BACKGROUND: Studies regarding the association between dietary fat intake and the development of breast cancer among postmenopausal women are lacking in Puerto Rico. METHODS: Eighteen cases and eighteen controls were interviewed to obtain sociodemographic information, medical history and dietary fat intake. A semiquantitative food frequency questionnaire containing 67 food items was used to collect the dietary information. RESULTS: Unadjusted odds ratios (OR) and their 95 per cent confidence intervals (CI) showed a non-significant positive association for total fat intake and the development of postmenopausal breast cancer (OR = 1.57; 95 per cent CI: 0.42-5.90, p = 0.25). The same non significant positive association was found for saturated fat intake (OR = 1.57; 95 per cent CI: 0.42-5.90, p = 0.25). Polyunsaturated fat (OR = 1.25; 95 per cent CI: 0.34-4.64, p = 0.37) and monounsaturated fat (OR = 1.25; 95 per cent CI: 0.34-4.64, p = 0.37) were also positively associated with postmenopausal breast cancer, although the associations were not statistically significant. CONCLUSIONS: These results are consistent with other case-control studies that have shown non-significant positive associations between total fat and the different components of dietary fat and postmenopausal breast cancer.

Cooking oils, cholesterol and CAD: facts and myths.

Elevated blood cholesterol is the strongest risk factor for coronary artery disease, and dietary excess of saturated fats is its largest contributor. Contrary to common belief, the contribution of dietary cholesterol to blood cholesterol is small. As a matter of fact, one need not consume cholesterol to have high blood cholesterol. Most vegetable cooking oils are low in saturated fats and are "heart healthy" with the important exception of tropical oils, such as coconut and palm oil, which are very rich in saturated fats. Though these oils contain no cholesterol, their cholesterol-raising potential is similar to or higher than most animal fats. Liberal use of these oils should be discouraged.

Cáncer vesicular: estudio de casos y controles en Chile / Gallbladder cancer: estudy of cases and controls in Chile

Estudio epidemiológico analítico de casos y controles, con 90 pacientes de cáncer vesicular verificado histológicamente y dos grupos de controles pareados por sexo y edad, uno con colelitiasis sin cáncer (colecistectomizados) y el otro, sin colelitiasis ni cáncer, según verificación ecográfica y seguimiento, completando 180 controles. A todos los enfermos se les aplicó una encuesta especialmente diseñada con 198 variables sociodemográficas, otras condiciones y patologías personales y familiares, medicamentos y algunos hábitos, especialmente de alimentación. Se encontró como factores de riesgo: antecedente de neoplasia familiar, mayor tiempo de evolución de la litiasis biliar y consumo aumentado de grasas y particularmente de ají en sus variedades verde y roja

Factores aterogénicos de la dieta de la población costarricense, 1991 / Aterogenic risk factors in the diet of Costa Rican Population, 1991

El presente estudio analiza los factores aterogénicos de la dieta de la población costarricense en diferentes grupos poblacionales y geográficos. Para ello se utilizan los datos de la II Encuesta Nacional sobre Consumo Aparente de Alimentos realizada en 1991. Los resultados muestran que a nivel nacional, el aporte de las grasas a la ingesta energénica total fue superior a las recomendaciones. Asimismo, lacontribución de la grasa saturada sobrepasa el límite establecido para la prevención de la enfermedad cardiovascular y, por el contrario, el aporte de grasa poliinsaturada fue inferior. Esta situación conlleva a una relación P/S de 0.3, valor que es considerado aterogénico. Dicho resultado se presenta en todas las zonas geográficas y condiciones socieconómicas del país. El consumo de colesterol se considera como adecuado. El índice CSI de la mayoría de las dietas estudiadas fue alto, situación semejante a reporte de otros países donde la enfermedad cardiovascular es la primera causa de muerte. El consumo de fibra dietética se encouentra cerca del límite inferior de la recomendación diaria. Asimismo, el consumo de las vitaminas C y E muestra valores normales, mientras que de vitamina A es deficiente. El principal alimento que contribuye a la ingesta de los tres tipos de grasa, así como de la vitamina E, fue la manteca vegetal, debido a su alto consumo en la población. El huevo es el alimento que aporta la mayor cantidad de colesterol a la dieta y la fibra dietética es aportada principalmente por frijoles. En conclusión. la dieta de la población costarricense presenta desbalance dietético por lo que puede ser considerada un factor de riesgo aterogénico

Nutritional significance of rice bran oil.

India is the second largest producer of rice in the world and has the high potential to produce rice bran oil (RBO), a by-product of the rice milling industry. Since RBO is, an unconventional oil, the chemical composition, nutrient evaluation and toxicological safety were assessed. The fatty acid composition RBO is very close to that of groundnut oil (GNO). Though RBO has high unsaponifiable matter (4.2%), it is rich In minor constituents such as phytosterols, triterpene alcohols, tocopherols and tocotrienols. Experimental as well as human studies have demonstrated the hypolipidaemic effects of RBO. Further, It was established that minor constituents present in unsaponifiable fraction of RBO were responsible for its hypolipidaemic effects. Nutritional evaluation studies, carried out with 10 per cent RBO and 20 per cent protein, indicated that growth, feed efficiency and mineral balance were comparable to GNO-fed animals. Toxicological studies had shown that there were no abnormalities In animals fed either RBO or GNO. The reproductive performance was also found to be normal as compared with that of GNO-fed animals in all three generations. In addition, neither RBO nor the foods deepfried in it showed any mutagenicity as judged by Ames test. In view of its safety and hypolipidaemic activity, RBO could be considered as an alternative source of edible oil.