Nutrient intake and food habits of soccer players: analyzing the correlates of eating practice.

Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player's career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players.

Fatty acids intake and immune parameters in the elderly.

INTRODUCTION: The rapid increase on life-expectancy represents a major challenge and economic burden for modern societies. Several studies have focused on the effects of polyunsaturated fatty acids (PUFA) upon the immune system; however less attention has been paid to the effects of monounsaturated fatty acids (MUFA). In this work we investigated the relationship of habitual consumption of different types of fatty acids with different immune parameters in the elderly. SUBJECTS AND METHODS: 40 institutionalized elderly (76-95 y) and 35 home-living middle-age subjects (57-65 y) were recruited. Dietary intakes of macronutrients, fiber and fatty acids, as well as immune parameters such as serum cytokines levels (IL-10, TNF-α, IL-8, IL-17, TGF-ß and IL-12), phagocytic activity and cytotoxic NK activity, were determined. RESULTS: Elderly subjects had a lower intake of total lipids. MUFA intake was significantly lower in the elderly group than in middle-age adults whilst the contrary was true for PUFA. MUFA intake in the elderly was found to be positively associated with IL-12 (ß = 0.879) and TNF-α (ß = 0.789) serum concentrations, whilst PUFA intake was inversely related to levels of IL-12 (ß = -0.534). These associations were not observed in the middle-age group. CONCLUSION: MUFA intake may contribute to the pro-inflammatory status present in the elderly. It may be advisable to develop future nutrient recommendations specific for elderly taking into account immune parameters.

Introducción: El rápido aumento de la esperanza de vida en las sociedades desarrolladas representa un gran desafío y supone una elevada carga económica. Numerosos trabajos han estudiado los efectos de los ácidos grasos poliinsaturados (AGP) sobre el sistema inmune, sin embargo los efectos de los ácidos grasos monoinsaturados (AGM) han recibido mucha menos atención. En este trabajo se investigó la relación del consumo habitual de los diferentes tipos de ácidos grasos con diversos parámetros inmunológicos en ancianos. Individuos y métodos: Se reclutaron 40 ancianos institucionalizados (79-95 AÑOs) y 35 individuos de mediana edad (57-65 AÑOs) que residían en sus hogares. Se determinó la ingesta diaria de macronutrientes, fibra y ácidos grasos, así como diversos parámetros inmunes; niveles séricos de citoquinas (IL-10, TNF-α, IL-8, IL-17, TGF-ß e IL-12), actividad fagocítica y actividad citotóxica de células NK. Resultados: Los voluntarios ancianos presentaron una menor ingesta de lípidos totales. La ingesta de AGM fue significativamente menor en el grupo de ancianos que en los adultos de mediana edad, mientras que lo contrario fue cierto para los AGP. La ingesta de AGM en ancianos se asoció positivamente con las concentraciones de IL-12 (ß = 0,879) y TNF-α (ß = 0,789), mientras que la ingesta de AGP mostró una relación inversa con los niveles de IL-12 (ß = -0,534). Estas asociaciones no fueron observadas en el grupo de mediana edad. Conclusión: La ingesta de AGM podría contribuir al estado pro-inflamatorio presente en los ancianos. Sería aconsejable desarrollar recomendaciones nutricionales específicas para ancianos teniendo en cuenta parámetros inmunológicos.

Fatty acids intake and immune parameters in the elderly / Ingesta de ácidos grasos y parámetros inmunes en ancianos

Introduction: The rapid increase on life-expectancy represents a major challenge and economic burden for modern societies. Several studies have focused on the effects of polyunsaturated fatty acids (PUFA) upon the immune system; however less attention has been paid to the effects of monounsaturated fatty acids (MUFA). In this work we investigated the relationship of habitual consumption of different types of fatty acids with different immune parameters in the elderly. Subjects and methods: 40 institutionalized elderly (76-95 y) and 35 home-living middle-age subjects (57-65 y) were recruited. Dietary intakes of macronutrients, fiber and fatty acids, as well as immune parameters such as serum cytokines levels (IL-10, TNF-α, IL-8, IL-17, TGF-β and IL-12), phagocytic activity and cytotoxic NK activity, were determined. Results: Elderly subjects had a lower intake of total lipids. MUFA intake was significantly lower in the elderly group than in middle-age adults whilst the contrary was true for PUFA. MUFA intake in the elderly was found to be positively associated with IL-12 (β = 0.879) and TNF-α (β = 0.789) serum concentrations, whilst PUFA intake was inversely related to levels of IL-12 (β = -0.534). These associations were not observed in the middle-age group. Conclusion: MUFA intake may contribute to the pro-inflammatory status present in the elderly. It may be advisable to develop future nutrient recommendations specific for elderly taking into account immune parameters (AU)

Introducción: El rápido aumento de la esperanza de vida en las sociedades desarrolladas representa un gran desafío y supone una elevada carga económica. Numerosos trabajos han estudiado los efectos de los ácidos grasos poliinsaturados (AGP) sobre el sistema inmune, sin embargo los efectos de los ácidos grasos monoinsaturados (AGM) han recibido mucha menos atención. En este trabajo se investigó la relación del consumo habitual de los diferentes tipos de ácidos grasos con diversos parámetros inmunológicos en ancianos. Individuos y métodos: Se reclutaron 40 ancianos institucionalizados (79-95 años) y 35 individuos de mediana edad (57-65 años) que residían en sus hogares. Se determinó la ingesta diaria de macronutrientes, fibra y ácidos grasos, así como diversos parámetros inmunes; niveles séricos de citoquinas (IL-10, TNF-α, IL-8, IL-17, TGF-β, IL-12), actividad fagocítica y actividad citotóxica de células NK. Resultados: Los voluntarios ancianos presentaron una menor ingesta de lípidos totales. La ingesta de AGM fue significativamente menor en el grupo de ancianos que en los adultos de mediana edad, mientras que lo contrario fue cierto para los AGP. La ingesta de AGM en ancianos se asoció positivamente con las concentraciones de IL-12 (β = 0,879) y TNF-α (β = 0,789), mientras que la ingesta de AGP mostró una relación inversa con los niveles de IL-12 (β = -0,534). Estas asociaciones no fueron observadas en el grupo de mediana edad. Conclusión: La ingesta de AGM podría contribuir al estado pro-inflamatorio presente en los ancianos. Sería aconsejable desarrollar recomendaciones nutricionales específicas para ancianos teniendo en cuenta parámetros inmunológicos (AU)

Microbial targets for the development of functional foods accordingly with nutritional and immune parameters altered in the elderly.

OBJECTIVE: The development of functional foods for microbiota modulation in the elderly constitutes an interesting strategy. However, for such development, specific targets, not just in terms of microbiota but also considering immune and nutritional parameters, should be identified in this population. METHODS: We analyzed the intestinal microbiota and immune parameters in 38 institutionalized elderly (mean 84 years old) and a group of 38 elderly adults (mean 62 years old). Nutritional assessments were also carried out. RESULTS: The elderly people in this study presented reduced levels of Faecalibacterium genus and Bacteroides and Blautia coccoides groups and increased Lactobacillus group, as well as reduced levels of fecal short-chain fatty acids (SCFA) when compared to younger adults. Moreover, they showed higher levels of the proinflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-12 as well as the chemokine IL-8. Significant nutritional deficiencies were also observed in the elderly group. CONCLUSION: The results obtained in this study suggest potential targets for the development of functional foods for the elderly population.

Is there a relationship between the playing position of soccer players and their food and macronutrient intake?

Many authors have proposed the necessity of the design and implementation of dietary and nutrition education programs for soccer players, although little information is available about the determinants of food selection and nutrient intake. The aim of this study was to evaluate the nutritional intake and eating patterns of soccer players according to their playing position in the team. Eighty-seven young male soccer players (aged 16-21 years) were recruited from the junior teams of a Spanish First Division Soccer League Club and divided into 6 positional categories (goalkeepers, full-backs, centre-backs, midfielders, wingers, and forwards). Body composition (height, weight, and body fat), performance in soccer-specific tests (jumping, sprinting, and intermittent endurance), and dietary intake (weighed food intake method) were assessed. A spontaneous higher carbohydrate intake was observed for full-backs, midfielders, and wingers (g·kg(-1) body mass: 4.9 ± 1.0, 4.9 ± 1.3, 4.9 ± 0.8; % of energy intake: 47 ± 5, 46 ± 6, 46 ± 4), compared with goalkeepers and centre-backs (g·kg(-1) of body mass: 3.9 ± 1.0, 4.3 ± 1.1; % of energy intake: 44 ± 3, 42 ± 4). These differences were related to food selection patterns, and a higher contribution to daily energy intake of cereals, derivatives, and potatoes was observed between full-backs compared with goalkeepers and centre-backs (33% vs. 27% and 25%). The magnitude of these differences is limited considering the whole diet, and an inadequate nutrient intake were observed in most individuals of every group. The design and implementation of nutrition intervention programs, taking into consideration positional differences in nutritional intake, would be useful for these players.

The relationship between dietary lipids and cognitive performance in an elderly population.

Epidemiological studies on the association between diet and cognitive function suggested a possible role of dietary fatty acids in cognitive decline. The aim of the present study was to examine whether intake of different types of fatty acids is associated with cognitive status. A cohort of 304 (127 men and 177 women) institutionalized elderly people, with a mean age of 75.3 +/- 6.7 years, were studied. Subjects were evaluated for global cognitive functions (Mini-Mental State Examination [MMSE], Spanish version). Fatty acid intake was assessed with a semi-quantitative food frequency questionnaire. Intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were found to be predictors of cognitive impairment as they were negatively associated with the MMSE score. In accordance with this, fish intake was inversely associated with cognitive impairment. On the contrary, the n-6/n-3 polyunsaturated fatty acid ratio was positively related to the MMSE score. These results could not be explained by differences in age, sex, education, smoking behaviour, inactivity, alcohol, institution or energy intake. We suggest that consumption of EPA and DHA should be encouraged for reducing the risk of cognitive impairment and subsequently disability in elderly people.

17beta-estradiol treatment is unable to reproduce p85 alpha redistribution associated with gestational insulin resistance in rats.

Maternal metabolic adaptations are essential to ensure proper fetal development. According to changes in insulin sensitivity, pregnancy can be divided into two periods: early pregnancy, characterized by an increase in maternal insulin sensitivity, and late pregnancy, in which there is a significant increase in insulin resistance. The aims of the present work were two-fold: firstly, the molecular mechanisms associated with the development of pregnancy-related insulin resistance in peripheral tissues, mainly retroperitoneal adipose tissue and skeletal muscle, were studied in pregnant rats at 6, 11, and 16 days gestation. Secondly, the role of 17beta-estradiol in this process was elucidated in an animal model consisting of ovariectomized rats treated with 17beta-estradiol to mimic plasma gestational levels. The results support the conclusion that retroperitoneal adipose tissue plays a pivotal role in the decrease in insulin sensitivity during pregnancy, through a mechanism that involves p85 alpha redistribution to the insulin receptor and impairment of Glut4 translocation to the plasma membrane. Treatment with 17beta-estradiol did not reproduce the molecular adaptations that occur during pregnancy, suggesting that other hormonal factors presents in gestation but absent in our experimental model are responsible for p85 alpha redistribution to the insulin receptor.

Differences in overall mortality in the elderly may be explained by diet.

BACKGROUND: Although a relationship between diet and mortality is well recognized, there is little information on the extent to which different food sources contribute to survival in elderly people. OBJECTIVE: To examine the effect of individual food groups on mortality in institutionalized elderly people from Asturias (Northern Spain) after 6 years of follow-up. METHOD: The dietary intake of 288 elderly people aged 60-85 years was assessed using a semiquantitative food frequency questionnaire (FFQ). Age, gender, energy intake, chewing ability, hyperglycemia, hypercholesterolemia, physical activity, smoking habit, self-perceived health, education level and the institution from which participants were recruited were covariates in Cox regression models analyzing the effect of food on survival. RESULTS: Fruit intake was found to be inversely associated with overall mortality. Multivariate adjusted mortality rate ratio (95% CI) per 1 SD increase in fruit intake was 0.714 (0.519-0.981). On the contrary, each 1 SD of potato intake led to a 32% higher risk of death (RR (95% CI) = 1.319 (1.033-1.685)). CONCLUSION: A high intake of fruit late in life was associated with a longer survival. An inverse association between potato intake and survival was also observed, but further research is necessary before any firm conclusions about the possible harmful aspects of potato consumption can be drawn.

Food preferences do not influence adolescent high-level athletes' dietary intake.

To assess the influence of preferences on food and nutritional intake in a group of adolescent high-level athletes, 22 male soccer players (14-16 years) were recruited. Individuals were asked to fill in a specific questionnaire including 15 food groups that had to be ranked according to their preferences. Three categories were established: "Like" (ranked 1-5), "Indifferent" (6-10), and "Dislike" (11-15). Dietary intake was assessed using the weighed food method (for nutrient intake) and a quantitative open-ended food frequency questionnaire (for the number of standard portions of each food group ingested daily). The main preferences were Meat, poultry and derivates (ranked 1-5 in 83% of individuals) and Pasta (58%), while Vegetables (ranked 11-15 in 82%) and Fish (64%) were the main dislikes. The most frequently consumed food groups were Fruits and fruit juices (3.9 portions/day), Bread (3.0), and Biscuits, confectionery and sweets (3.0). No statistical differences were found in food consumption between preference groups, and no relation was found between preferences and nutritional intake, except for those individuals who especially like Bread, which had statistically higher energy and carbohydrate intake. Food preferences and food and nutritional intake of adolescent high-level soccer players were, effectively, unrelated.

Homocysteine increases the risk of mortality in elderly individuals.

Although total plasma homocysteine (tHcy) has been extensively studied as a risk factor of CVD, longitudinal evidence on its association with mortality is scarce, especially among the elderly. The study cohort consisted of 215 subjects (eighty-eight male and 127 female), aged 60 years or older, recruited in fourteen elderly care institutions from Asturias (Spain). All participants were free of major chronic pathology and took no vitamin and/or mineral supplements. Baseline determinations included tHcy in plasma and folate, vitamin B12 and Se in serum. Survival analyses were performed by quintiles of these factors after 6 years (mean follow-up time 4.3 years) by means of Cox regression models. During follow-up time sixty participants died. tHcy above 16.7 micromol/l was associated with an increased risk of mortality in the sample (relative risk 2.30 (95 % CI 1.02, 5.17)). Among the nutritional determinants of tHcy evaluated, folate and Se were not predictive of death risk of the cohort, while vitamin B12 showed inconsistent results. Nevertheless, mortality was significantly lower at higher serum Se levels (upper quintile), but this effect was restricted to women. Higher tHcy in both sexes and lower serum Se in women were found to be independently associated with an increased risk of death in elderly subjects.

Life-quality indicators in elderly people are influenced by selenium status.

BACKGROUND AND AIMS: Selenium is of fundamental importance to human health. Our aim was to evaluate the effect of selenium (intake and serum levels) on subjective indicators of quality of life in older people, such as self-perceived health, chewing ability and physical activity. METHODS: The sample was a cohort of 227 elderly people (93 men and 134 women) residing in 14 nursing homes in Asturias (Spain). Mean age +/- SD was 72.9+/-7.2 y and 76.4+/-5.9 y, for men and women respectively. Information was collected in personal interviews. Dietary intake was recorded by means of a food-frequency questionnaire. Selenium was determined in serum by graphite-furnace atomic absorption spectrometry. RESULTS: Serum selenium was associated with self-perceived health, chewing ability and physical activity in this sample. Subjects in the upper tertile of serum selenium had more than twice as much probability (Odds Ratios, 2.05 to 3.157) of reporting good health status, good chewing ability and of doing more than 60 min of exercise/day. CONCLUSIONS: The maintenance of good serum selenium levels is important, since it may affect the self-perception of health, chewing ability, or physical activity and, consequently, the quality of life in elderly people.

Regulation of estrogen receptor alpha by estradiol in pregnant and estradiol treated rats.

Estrogens play an important role in tissue metabolism through specific regulation of several intracellular pathways. We studied ERalpha regulation in muscle and adipose tissue from pregnant and estradiol treated rats. In both groups, we identified three different ERalpha inmunoreactive proteins (80, 67 and 46 kDa) using total protein extracts. Because it has been showed that estrogens are able to promote rapid effects in several cellular models, we looked for three ERalpha-related proteins at plasma membrane. In skeletal muscle of both groups, we positively identified the three ERalpha-related isoforms in plasma membrane, but in adipose tissue from pregnant we were not able to identify ERalpha67, and in estradiol treated animals ERalpha80 was absent. Taking together, our results showed a tissue-specific regulation of whole-cell ERalpha-related proteins and ERalpha located at plasma membrane, which should be involved in non-genomic actions of 17beta-estradiol. The role of the three ERalpha inmunoreactive proteins is unknown, however, seems probably related to rapid activation of signalling pathways.

Lipid peroxidation, antioxidant status and survival in institutionalised elderly: a five-year longitudinal study.

Oxidative stress has been related to ageing and risk of death. To determine whether oxidative status was associated with all-cause risk of death we carried out a prospective study in 154 non-smoking Spanish elderly without major illness. Baseline glutathione peroxidase (GPx) and superoxide dismutase (SOD) were analysed in plasma and erythrocytes. alpha-tocopherol, beta-carotene, lycopene and retinol were determined in serum samples and malondialdehyde (MDA), as a lipid peroxidation marker, in plasma. Mean survival time was 4.3 years. A total of 31 death cases (20.1%) occurred during the follow-up. Plasma-MDA predicted mortality independently of all other variables, while erythrocyte-SOD (e-SOD), beta-carotene and alpha-tocopherol were positively associated with survival. alpha-tocopherol and MDA were revealed as independent predictors in a joint survival model, being the group with low MDA and high alpha-tocopherol that with the lowest mortality. In conclusion, a higher risk of death was associated with increased lipid peroxidation and lower antioxidant defenses.

Effect of food restriction on the insulin signalling pathway in rat skeletal muscle and adipose tissue.

We tried to elucidate the effects of a brief and severe model of food restriction on insulin sensitivity in female rats, focusing on key proteins involved in the insulin signalling pathway in skeletal muscle and adipose tissue after 5, 10 and 15 days of food restriction. Using euglycemic clamp, we detected that food-restricted rats are significantly less sensitive to insulin action than control rats. However, the time of restriction promotes a progressive increase on insulin sensitivity. The analysis of the insulin signalling pathway showed a tissue-specific regulation of several proteins involved in insulin signalling. In skeletal muscle, insulin receptor substrate 1 and Glut4 are up-regulated at the end of the food restriction period, just the opposite of what we found in adipose tissue. In conclusion, a 50% reduction of food intake modulates insulin sensitivity through a tissue-specific regulation of the insulin signalling pathway in the main target tissues for this hormone.

Food habits and nutritional status assessment of adolescent soccer players. A necessary and accurate approach.

The aim of this study was to assess the food habits and nutritional status of high level adolescent soccer players (N = 33; ages 14-16 yrs) living in their home environment. Body composition (height, mass, skinfolds), biochemical and hematological parameters, performance in soccer-specific tests (sprinting, jumping, intermittent endurance), and dietary intake (weighed food intake method) and related behaviors (nutrient supplement use, daily activity profile) were assessed. Daily energy expenditure and energy intake were 12.5 MJ and 12.6 MJ, respectively. Protein (16% of energy intake; 1.9 g/kg of body mass), lipid (38%), and cholesterol (385 mg) intake were above recommendations, while carbohydrates (45%) were below. The food intake of these adolescents was based on cereals and derivates; meat, fish, and eggs; milk and dairy products; biscuits and confectionery; and oil, butter and margarine, which provided 78% of total energy intake, 85% of proteins, 64% of carbohydrates, 90% of lipids, and 47% of fiber. Although diet provided sufficient iron, 48% of individuals showed iron deficiency without anemia. Based on these results, a well designed nutrition intervention would be advisable for optimizing performance, and especially for promoting healthy eating habits in adolescent soccer players.

No evidence for oxidative stress as a mechanism of action of hyperhomocysteinemia in humans.

Oxidative stress has been suggested as one of the physiopathologic conditions underlying the association of total plasma homocysteine (p-tHcy) with cardiovascular disease (CVD), but this hypothesis has not been validated in human epidemiological studies. We measured plasma and erythrocyte antioxidant enzymes glutathione peroxidase (GPx) and superoxide dismutase (SOD), along with serum lipid-soluble antioxidants alpha-tocopherol, beta-carotene, lycopene and retinol, in a sample of 123 healthy elderly subjects (54 men, 69 women). Plasma malondialdehyde (p-MDA) was determined as a marker of lipid peroxidation, and p-tHcy was quantified by HPLC. No significant differences were found for p-MDA, GPx or SOD activities or serum antioxidant concentrations, in subjects with elevated p-tHcy (> or =15 micromol/l) as compared to those with lower plasma homocysteine. Hyperhomocysteinemia did not lead to increased risk of having the highest p-MDA values, in either sex. We found no evidence that p-tHcy was associated with lipid peroxidation in this elderly human sample. Our results do not support the view that hyperhomocysteinemia would induce an adaptive response of antioxidant systems, either. More epidemiologic and clinical research is needed to clarify whether homocysteine promotes atherosclerosis by means of an oxidative stress mechanism.

Folate and cobalamin synergistically decrease the risk of high plasma homocysteine in a nonsupplemented elderly institutionalized population.

OBJECTIVE: Total plasma homocysteine (tHcy) has been associated with an increased risk of cardiovascular disease in the general population and elderly subjects are at high risk of elevated homocysteine because of an impaired vitamin status. The aim of the present study was to determine the independent and interactive association of adequate folate and cobalamin (intake and serum levels) with tHcy in elderly subjects who were not taking vitamin supplementation. DESIGN AND METHODS: Cross-sectional analysis of a sample of 140 elderly recruited from seven nursing homes in Asturias (Northern Spain). Dietary intake was assessed by a food frequency questionnaire, and serum folate, cobalamin, and tHcy were determined in fasting blood samples. RESULTS: Mean tHcy concentration was 13.3 micromol/L (upper quartile of tHcy >16.0 micromol/L) and was inversely correlated with serum folate. Subjects with an adequate intake or serum levels of both folate and B12 were at a reduced risk of being in the highest quartile of tHcy. In both cases, the reduction of high tHcy (upper quartile) risk was found to be greater than expected when subjects with high levels of both vitamins were considered together. CONCLUSIONS: Adequate folate and cobalamin (both intake and serum levels) act synergistically to decrease the risk of high total plasma homocysteine levels in this elderly population.

Serum selenium is associated with plasma homocysteine concentrations in elderly humans.

Low selenium levels in humans have been associated with several pathologies; however, an earlier animal investigation found a direct association between Se intake and total plasma homocysteine (tHcy) concentrations. To date, the importance of serum selenium levels in association with tHcy in humans has not been determined. We evaluated the cross-sectional association of blood selenium concentrations with plasma tHcy and other determinants of this cardiovascular disease risk factor. We estimated protein intake and measured the blood status of selenium, tHcy, and several other related factors in serum such as folate, vitamin B-12, and creatinine. Serum selenium was inversely associated with tHcy, explaining 5.8% of tHcy variance with respect to 2.2% accounted for by serum folate. Furthermore, there was a 63% decreased risk of higher tHcy concentrations (>14 micro mol/L) for subjects with serum selenium in the highest tertile (P = 0.013). We also found an inverse association of protein intake with tHcy in men (beta = -0.144; P = 0.036), which disappeared after controlling for serum Se concentrations (beta = -0.055; P = 0.003). In conclusion, selenium should be considered as a potential factor to lower tHcy. In addition, the described association between protein intake and homocysteine levels could be mediated by this trace element.

Food habits are associated with lipid peroxidation in an elderly population.

OBJECTIVE: The purpose of this study was to assess the association between dietary intake and lipid peroxidation. DESIGN: Cross-sectional population analysis from an ongoing prospective study. Malondialdehyde (MDA) was measured as a marker of lipid peroxidation. Diet was assessed through direct observation and food frequency questionnaire. SUBJECTS: Participants with no missing data were 162 nonsmoking elderly individuals residing in 7 institutions across Asturias (Spain). STATISTICAL ANALYSES PERFORMED: Comparisons of adjusted group means by tertiles of plasma MDA were made by analysis of variance. Stepwise regression analysis was done using MDA as a dependent variable and food intake as an independent variable. Food intakes were categorized into quartiles and logistic regression was applied to calculate the odds ratio for being in the highest tertile of plasma MDA. RESULTS: Consumption of potatoes had an independent direct effect and accounted for a sizeable proportion of the variation in plasma MDA levels (18%, P<.001). In addition to potatoes, other foods that had an apparently independent effect on plasma MDA were eggs, cooked vegetables, and red wine (R(2)=0.028, 0.023 and 0.018, respectively). In this study, dietary factors accounted for 25% of the variation in plasma MDA levels. CONCLUSION: Identifying nutritional determinants of oxidative stress is important because of its negative health effect. Consumption of cooked vegetables and moderate intake of wine has been shown to be appropriate for reducing the risk of oxidative damage. On the contrary, caution must be used with the intake of potatoes because we have found a positive association with MDA levels. Further studies are required to investigate the mechanism(s) of this association and whether it is related to the preparation method or to the potato itself.

Plasma iron is associated with lipid peroxidation in an elderly population.

Epidemiological evidence has raised concern that a moderate elevation in body iron stores may increase oxidative stress and risk of heart disease. We examined the cross-sectional association between plasma iron and factors that could affect its levels (antioxidant enzymes, diet), with the concentration of plasma malondialdehyde (MDA) as a marker of lipid peroxidation. Participants were 162 non-smoking institutionalised elderly. Our results show that those in the highest tertile of plasma iron were at least twice as likely to have higher plasma MDA levels. Among the factors affecting plasma iron levels, we found that the upper tertile of erythrocyte-superoxide dismutase (E-SOD) was inversely associated with higher plasma iron, and potato intake explained a sizeable proportion of the variation in plasma iron levels. In addition to potatoes, eggs, wine, fruit in men and green vegetables in women showed a positive association with plasma iron levels. Only potatoes in both sexes, wine in men and eggs in women had an independent effect on plasma MDA. Potatoes, wine, plasma lycopene and plasma iron accounted for 43% of the variability in plasma MDA for males, and E-SOD, potatoes, eggs, plasma lycopene and plasma iron explained 45% for women. A longitudinal study should confirm, whether these MDA levels are related to morbidity and mortality.