Biomedical subjects

Magdalena López-Frías

Publications and source records attributed to Magdalena López-Frías.

6 recordsLinked to original sources

PubMed2006

Diets rich in Maillard reaction products affect protein digestibility in adolescent males aged 11-14 y.

BACKGROUND: Adolescents are nutritionally at risk because of their physiologic needs and dietary habits. Maillard reaction products (MRPs) are widely consumed by this population, mainly as a result of their high intake of fast food and snacks. OBJECTIVE: We compared the effects of diets with different MRP contents on dietary protein utilization in adolescent males aged 11-14 y. The brown diet (BD) was rich and the white diet (WD) was poor in MRP content (hydroxymethylfurfural: 3.87 and 0.94 mg/kg; fluorescence intensity: 21.04% and 7.31%, respectively). DESIGN: In a 2-period crossover trial, 18 healthy adolescent males were randomly assigned to 2 groups. The first group consumed the WD for 2 wk, observed a 40-d washout period, and then consumed the BD for 2 wk. The second group received the diets in the opposite order. Subjects collected urine and feces on the last 3 d of each dietary period. Fasting blood samples were collected after both periods. RESULTS: Compared with consumption of the WD, consumption of the BD resulted in 47% higher fecal nitrogen fecal excretion (P = 0.002), 12% lower apparent nitrogen absorption (P = 0.000), and a 6% lower nitrogen digestibility (P = 0.000). The apparent nitrogen retention and the utilization of ingested nitrogen did not differ significantly between the diets, although values after the BD tended to decrease. Serum biochemical variables related to nitrogen metabolism did not differ significantly. CONCLUSIONS: The consumption of a diet rich in MRPs negatively affects protein digestibility. The possible effects of an excessive intake of MRPs during adolescence warrant attention, and long-term effects should be considered.

Adolescent↗

PubMed2005

Nutrient intake adequacy in schoolchildren from a Mediterranean area (southern Spain). Influence of the use of the school canteen.

The aim of the present study was to compare dietary adequacy in 521 schoolchildren in Granada (Spain) with national recommendations and to determine possible differences regarding gender or the use of the school canteen. A food record was used for four consecutive days to evaluate the intake of nutrients and foods. With regard to boys' and girls' intake of the main groups of foods, we observed a tendency for the boys to consume greater quantities of dairy products, cereals, potatoes, and fruit, although the differences were not statistically significant. The children who lunched at school consumed fish, eggs, dairy products, vegetables, and cereals more frequently than those who did so at home. The mean daily intake of energy and nutrients indicates that the studied population exceeded the recommended limits in the proportion of energy derived from protein and fat, while carbohydrate intake was slightly deficient. The children who lunched at school showed a more favorable profile for energy and nutrient intake, with a significantly higher intake of energy, carbohydrates, total fat, polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), vitamins B, and E, and calcium, with respect to the children who had lunch at home.

Animals↗

PubMed2005

Factors associated with obesity in an adult Mediterranean population: influence on plasma lipid profile.

OBJECTIVE: The aim of the study was to identify factors associated with obesity, and their influence on plasma lipid profile in an adult Mediterranean population. DESIGN: The data were obtained from a cross-sectional epidemiological survey. SETTING: The study population resided in Andalusia, a western Mediterranean region in southern Spain. SUBJECTS: The survey was carried out with a random sample of 3421 subjects (1747 men, 1674 women) between 25 and 60 years of age. Blood samples were obtained for biochemical assays in a random subsample of 340 subjects (167 men, 173 women). INTERVENTIONS: Food consumption was assessed by 48-h recall. Height, weight, triceps, biceps, subscapular and suprailiac skinfolds, mid-upper arm, waist (WC) and hip circumferences, glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides were measured. Information about lifestyles was obtained with a questionnaire. RESULTS: Of the adult population we studied, 18.9% were obese (body mass index [BMI] > or = 30 kg/m2). A larger proportion of men than women were overweight, but the opposite was found for obesity. Mean plasma lipid values were not modified significantly by obesity or lifestyle factors, and were within the normal range. Sex, age, physical exercise and lower educational level were associated directly with the risk of obesity, and smoking was associated inversely with the risk of obesity. In obese smokers WC and waist-hip ratio were larger, and levels of HDL-cholesterol were lower (p < 0.05) than in obese nonsmokers. Glucemia was higher in obese persons who consumed alcohol (p < 0.05) than in obese persons who did not consume alcohol. The risk of hypercholesterolemia and high levels of LDL-cholesterol was associated only with age, and the risk of low levels of HDL-cholesterol was associated only with high WC. CONCLUSION: Our results provide an estimate of the prevalence of obesity in the adult population in southern Spain, and of the associated factors. Sex, age, leisure-time physical exercise and educational level appear to influence obesity. Only age and WC but not BMI were associated with a risk of dyslipidemia. No dietary associations were observed between energy or macronutrient intake and plasma lipid concentrations in overweight or obese persons.

Adult↗

PubMed2003

Effect of different soaking solutions on nutritive utilization of minerals (calcium, phosphorus, and magnesium) from cooked beans (Phaseolus vulgaris L.) in growing rats.

The effects of the commonly used processing techniques of soaking (at different pH values) and cooking on the digestive and nutritive utilization of calcium, phosphorus, and magnesium from common beans (Phaseolus vulgaris L.) were studied. Before the cooking step, the beans were soaked in solutions of acid (2.6 and 5.3) or basic (8.4) pH. Chemical and biological methods were used to determine nutritional parameters in growing rats, and the fiber content of the beans was established. As the pH of the soaking solution increased, so did mineral absorption and the apparent digestibility coefficient, which reached suitable values for growing rats, due to the reduced losses of soluble minerals and the increased food intake. Metabolic utilization also improved with increased pH of the soaking solution, although the values were, in general, low as a result of urinary losses under the experimental conditions. For the experimental period of 10 days, the femur and the muscle seem to be good metabolic indicators for calcium, but not for phosphorus or magnesium. The increased amount of cellulose in the soaked seed did not have a negative effect on the digestive utilization of minerals.

Animals↗

PubMed2003

Aging-related oxidative stress depends on dietary lipid source in rat postmitotic tissues.

We investigate mitochondrial-lipid peroxidation of mitotic (liver) and postmitotic (heart and skeletal muscle) tissues of rats fed lifelong on two different lipid sources: virgin olive oil (monounsaturated fatty acids) and sunflower oil (n - 6 polyunsaturated fatty acids). Two groups of 80 rats each were fed over 24 months on a diet differing in the lipid source (virgin olive oil or sunflower oil). Twenty rats per group were killed at 6, 12, 18, and 24 months; liver, heart, and skeletal muscle mitochondria were isolated and the lipid profile, hydroperoxides, vitamin E, and ubiquinone as well as catalase activity measured. Lipid peroxidation was higher in postmitotic tissues, and sunflower oil led to a higher degree of polyunsaturation and peroxidation. The levels of alpha-tocopherol adapted to oxidative stress and preferentially accumulated during aging in heart and skeletal muscle. In conclusion, the type of dietary fat should be considered in studies on aging, since oxidative stress is directly modulated by this factor. This study confirms that postmitotic tissues are more prone to oxidative stress during aging and proposes a hypothesis to explain this phenomenon.

Aging↗

PubMed2002

Ageing-related tissue-specific alterations in mitochondrial composition and function are modulated by dietary fat type in the rat.

This study investigated the way in which feeding rats with two fat sources (olive or sunflower oils) affected electron-transport components and function of mitotic (liver) and postmitotic (heart and skeletal muscle) tissues during ageing. Rats adapted the mitochondrial-membrane-lipid profile to dietary fat throughout the study, suggesting that the benefits to eat either of the two fats might be maintained lifelong. Liver was more resistant to dietary changes and ageing than heart and skeletal muscle, which showed higher levels of coenzyme Q, cytochrome b, and cytochrome a + a3 with ageing and lower cytochrome c oxidase and complex IV turnover. Dietary fat differentially modulated the response of tissues during ageing, with sunflower oil leading to the highest levels of coenzyme Q and cytochromes b and a + a3. Since high levels of cytochrome b have been related to increased age, it could be hypothesized that olive oil could lead to less aged mitochondria.

Aging↗