Fasting Ghrelin Levels Are Decreased in Obese Subjects and Are Significantly Related With Insulin Resistance and Body Mass Index.

BACKGROUND: Ghrelin is a 28-amino acid peptide that predominantly produced by the stomach. Strong evidence indicates the effects of ghrelin in the regulation of metabolic functions and its potential role in the aetiology of obesity. AIM: The aim of this study was to investigate the relationship of ghrelin levels with obesity, insulin resistance and glucose in normal and obese subjects. METHODS: Thirteen normal (n = 13) and seven (n = 7) obese weight subjects aged 20-22 participated in the study. Fasting plasma ghrelin, insulin and glucose levels were measured after overnight fasting. HOMA-IR was calculated to evaluate insulin resistance. RESULTS: Ghrelin and insulin levels were found to be statistically significantly lower and higher in obese subjects (P < 0.001), respectively. Glucose levels were clinically higher in obese subjects but not statistically significant. Fasting plasma ghrelin was negatively correlated with BMI (r = -0.77, P < 0.001), fasting insulin levels (r = -0.55, P < 0.001) and HOMA-IR (r = -0.66, P < 0.001). There was no correlation between ghrelin and glucose. In multiple regression analysis, insulin levels (Beta:-2.66, 95%CI:-2.49, -2.78, P < 0.001) HOMA-IR (Beta:-2.41, 95%CI:-2.33, -2.55, P < 0.001) and BMI (Beta:-1.77, 95%CI:-1.66, -1.89, P < 0.001) were significant independent determinants of fasting ghrelin. CONCLUSION: Obese subjects have low fasting ghrelin levels that they are significantly related to insulin resistance and body mass index. More prospective studies are needed to establish the role of ghrelin in the pathogenesis of human obesity.

Adherence to the Mediterranean type of diet is associated with lower prevalence of asthma symptoms, among 10-12 years old children: the PANACEA study.

Epidemiological studies have shown several associations between asthma symptoms and dietary factors. The aim of this work was to evaluate the relationship between adherence to the Mediterranean diet and childhood asthma. A cross-sectional analysis was performed on 700 children (323 boys), 10-12 yr old, selected from 18 schools located in Athens greater area. Children and their parents completed questionnaires, which evaluated, among others, dietary habits. Asthma was defined according to ISAAC II criteria. Adherence to the Mediterranean diet was evaluated using the KIDMED score (theoretical range 0-12). Higher KIDMED score corresponds to greater adherence to the Mediterranean diet. Greater adherence to the Mediterranean diet was inversely associated with ever had wheeze (p = 0.001), exercise wheeze (p = 0.004), ever had diagnosed asthma (p = 0.002) and with any asthma symptoms (p < 0.001). One-unit increase in the KIDMED score was associated with 14% lower likelihood of having asthma symptoms (odds ratio = 0.86, 95% confidence interval 0.75-0.98), after adjusting for various confounders. No significant associations were found between asthma symptoms and consumption of fruits (p = 0.25), vegetables (p = 0.97), legumes (p = 0.76), cereals (p = 0.71), dairy (p = 0.61), salty snacks (p = 0.53), or margarine/butter (p = 0.42) consumption, while increased fish and meat intake was associated with less asthma symptoms (p = 0.04 and p = 0.01, respectively). Our findings suggest an inverse relationship between level of adherence to the Mediterranean diet and prevalence of asthma in school-aged children.

Salty-snack eating, television or video-game viewing, and asthma symptoms among 10- to 12-year-old children: the PANACEA study.

BACKGROUND: Salty-snack consumption, as well as the amount of time children spend watching television or playing video games, have been implicated in the development of asthma; however, results are still conflicting. OBJECTIVE: The aim of this work was to evaluate the association of salty-snack eating and television/video-game viewing with childhood asthma symptoms. DESIGN: Cross-sectional study. SETTINGS: Seven hundred children (323 male), 10 to 12 years old, from 18 schools located in the greater area of Athens were enrolled. Children and their parents completed questionnaires, which evaluated, among other things, dietary habits. Adherence to the Mediterranean diet was evaluated using the KIDMED (Mediterranean Diet Quality Index for Children and Adolescents) score. STATISTICAL ANALYSIS: The association of children's characteristics with asthma symptoms was performed by calculating the odds ratios and corresponding 95% confidence intervals. RESULTS: Overall lifetime prevalence of asthma symptoms was 23.7% (27.6% boys, 20.4% girls; P=0.03). Forty-eight percent of children reported salty-snack consumption (≥ 1 times/week). Salty-snack consumption was positively associated with the hours of television/video-game viewing (P=0.04) and inversely with the KIDMED score (P=0.02). Consumption of salty snacks (>3 times/week vs never/rare) was associated with a 4.8-times higher likelihood of having asthma symptoms (95% confidence interval: 1.50 to 15.8), irrespective of potential confounders. The associations of salty-snack eating and asthma symptoms were more prominent in children who watched television or played video games >2 hours/day. In addition, adherence to the Mediterranean diet was inversely associated with the likelihood of asthma symptoms. CONCLUSIONS: Unhealthy lifestyle behaviors, such as salty-snack eating and television/video-game viewing were strongly associated with the presence of asthma symptoms. Future interventions and public health messages should be focused on changing these behaviors from the early stages of life.

Dietary habits and asthma: a review.

Many risk factors for the development of asthma and allergies have been proposed; although genetics are a major factor, the subject's environment and lifestyle may also contribute maximally to the disease. The role of diet has recently been investigated and recognized as a potential risk factor. It has been suggested that the rise in asthma prevalence may partly reflect changes in the population susceptibility resulting from alteration in diet, especially a fall in antioxidant intake, rather than increasing environmental toxicity. Many studies have shown that the decreased consumption of fresh fruit, vegetables, fish, and the increased intake of food rich in fat, is associated with increased risk of developing asthma. More recently, larger dietary patterns beyond individual nutrients have been investigated such as the Mediterranean diet. However, the results of these studies are inconsistent and even contradictory. Despite some promising hypotheses and findings, there has been no conclusive evidence about the role of specific nutrients, food types, or dietary patterns in the development of asthma.

Healthy indexes in public health practice and research: a review.

The scientific community has long been interested in the overall quality of diets owing to the fact that it is important for each individual's health through a healthy, varied, and balanced diet. Much research has been conducted on methods used to measure dietary quality. These studies led to the determination of numerous indices, some very simple and some much more complex. Indices that examine diets for several attributes concurrently are able to provide a measure of overall diet quality that is not possible when only single nutrients or food groups are examined. Using these indices, diet quality may be evaluated in relation to nutrient adequacy, compliance with dietary guidelines, or nutrition recommendations, association with risk of chronic diseases, or mortality, and used to assess interventions. However, there are several factors that should be taken into consideration for the design of an index, like the purpose of its use, as well as its simplicity in daily practice. The general purpose of an index is to synthesize a large amount of information into a single useful indicator. The purpose of this review was to present and to critically review the most commonly used dietary indices, and how they reflect various aspects of diet quality. The majority of these indices fail to recognize the various inter-relationships between their components, as well as their accuracy for estimating specific health outcomes. Thus, the development of weighted dietary indices that adequately assess a dietary pattern and its relationship to the burden of a disease is considered essential.

Adherence to the Mediterranean food pattern predicts the prevalence of hypertension, hypercholesterolemia, diabetes and obesity, among healthy adults; the accuracy of the MedDietScore.

OBJECTIVE: We sought to evaluate the accuracy of a diet score in relation to hypertension, hypercholesterolemia, diabetes and obesity. METHODS: A diet score (range 0-55) has been developed that assesses adherence to the Mediterranean diet. For the consumption of items presumed to be close to Mediterranean dietary pattern (non-refined cereals, fruits, vegetables, legumes, olive oil, fish and potatoes) scores 0 to 5 for never, rare, frequent, very frequent, weekly and daily consumption were assigned, while for the consumption of foods presumed to be away from this pattern (red meat and products, poultry and full fat dairy products) scores on a reverse scale were assigned. Positive and negative predictive values, in relation to hypertension, hypercholesterolemia, diabetes and obesity status of the ATTICA study participants (n=3042, enrolment 2001-02 in Athens metropolitan area, aged 18-89 years) were calculated and the 10-year CHD risk based on Framingham equations was estimated, too. RESULTS: The positive predictive values of the score regarding hypertension, hypercholesterolemia, diabetes and obesity are: 45% (95% CI 43%-48%), 46% (95% CI 44%-49%), 12% (95% CI 11%-14%) and 33% (95% CI 30%-35%), while the negative predictive values are 86% (95% CI 85%-88%), 71% (95% CI 69%-74%), 98% (95% CI 97%-99%) and 97% (95% CI 96%-98%), respectively. Moreover, a 10-unit increase in the diet score is associated with 4% lower 10-year CHD risk (+/-0.1%, p<0.001). CONCLUSION: The proposed Mediterranean Diet Score may be useful in detecting individuals prone to the development of nutrition-related health conditions and cardiovascular disease.

Dietary habits in a Greek sample of men and women: the ATTICA study.

OBJECTIVE: Although there are several dietary guidelines accepted at the international and national level, there are indications that dietary habits in Greece have been changing, moving away from the traditional Mediterranean diet pattern. The aim of this work was to evaluate the dietary habits of a randomly selected sample from the general adult population, in Greece. SUBJECTS: The "ATTICA" study is a prospective health and nutrition survey. For the purpose of this study, 3,042 adults, from whom 1514 were men (48%) and 1,528 were women (52%), were selected from the greater Athens area during 2001 and 2002. The assessment of the dietary habits was carried out using a validated food frequency questionnaire. RESULTS: Dietary intakes of red meat and sweets were higher (p<0.005), and dietary intakes of fish, poultry, dairy products, vegetables, and cereals were lower (p<0.05) than the ones recommended by the Hellenic Ministry of Health. CONCLUSION: The results from the present study indicate a change in the dietary habits towards an unhealthier type of diet.

Organic food: buying more safety or just peace of mind? A critical review of the literature.

Consumer concern over the quality and safety of conventional food has intensified in recent years, and primarily drives the increasing demand for organically grown food, which is perceived as healthier and safer. Relevant scientific evidence, however, is scarce, while anecdotal reports abound. Although there is an urgent need for information related to health benefits and/or hazards of food products of both origins, generalized conclusions remain tentative in the absence of adequate comparative data. Organic fruits and vegetables can be expected to contain fewer agrochemical residues than conventionally grown alternatives; yet, the significance of this difference is questionable, inasmuch as actual levels of contamination in both types of food are generally well below acceptable limits. Also, some leafy, root, and tuber organic vegetables appear to have lower nitrate content compared with conventional ones, but whether or not dietary nitrate indeed constitutes a threat to human health is a matter of debate. On the other hand, no differences can be identified for environmental contaminants (e.g. cadmium and other heavy metals), which are likely to be present in food from both origins. With respect to other food hazards, such as endogenous plant toxins, biological pesticides and pathogenic microorganisms, available evidence is extremely limited preventing generalized statements. Also, results for mycotoxin contamination in cereal crops are variable and inconclusive; hence, no clear picture emerges. It is difficult, therefore, to weigh the risks, but what should be made clear is that 'organic' does not automatically equal 'safe.' Additional studies in this area of research are warranted. At our present state of knowledge, other factors rather than safety aspects seem to speak in favor of organic food.

Identifying nutritionally vulnerable groups in case of emergencies: experience from the Athens 1999 earthquake.

During emergency situations in developing countries, young children have been identified as the most nutritionally vulnerable group. Comparatively less is known regarding nutritional risk of individuals in well-nourished societies hit by a major disaster. The aim of the present study, therefore, was to assess the nutritional status of Greek people who were left homeless after the Athens 1999 earthquake. A total of 225 volunteers from two camps were surveyed for dietary intake information and surrogate measures of nutritional status. Energy consumption and anthropometric indices of the children and adolescents revealed no sign of undernourishment. On the other hand, adults and the elderly consumed considerably less energy than that required for long-term preservation of health. Short-term energy and protein deficits, however, did not jeopardise their nutritional status as it might have expected, on the basis of high body mass indexes and normal haematological and biochemical profiles that were documented. In conclusion, the results of the present study indicate that nutritional risk in the acute phase after a major emergency in a previously well-nourished population is rather low. This is especially true for younger individuals, probably due to increased provision from the family and the community. Nevertheless, older persons may face increased risk as the situation is prolonged.

Organic food: nutritious food or food for thought? A review of the evidence.

Apparently, one of the primary reasons for purchasing organic food is the perception that it is more nutritious than conventional food. Given the increasing interest towards organic food products, it is imperative to review the existing literature concerning the nutritional value of the produce, and to determine to what extent are consumer expectations met. There are only few well-controlled studies that are capable of making a valid comparison and, therefore, compilation of the results is difficult and generalisation of the conclusions should be made with caution. In spite of these limitations, however, some differences can be identified. Although there is little evidence that organic and conventional foods differ in respect to the concentrations of the various micronutrients (vitamins, minerals and trace elements), there seems to be a slight trend towards higher ascorbic acid content in organically grown leafy vegetables and potatoes. There is also a trend towards lower protein concentration but of higher quality in some organic vegetables and cereal crops. With respect to the rest of the nutrients and the other food groups, existing evidence is inadequate to allow for valid conclusions. Finally, animal feeding experiments indicate that animal health and reproductive performance are slightly improved when they are organically fed. A similar finding has not yet been identified in humans. Several important directions can be highlighted for future research; it seems, however, that despite any differences, a well-balanced diet can equally improve health regardless of its organic or conventional origin.

Putting the safety of organic food into perspective.

The demand for organic foods is constantly increasing mainly due to consumers' perception that they are healthier and safer than conventional foods. There is a need for information related to food safety to inform consumers of the health benefits and/or hazards of food products of both origins, in order to optimise the impact on health and minimise the risks. Several gaps and limitations in scientific knowledge with regard to food risk evaluation make it difficult to draw generalised conclusions. Still, some organic foods can be expected to contain fewer agrochemical residues and lower levels of nitrate than conventionally grown alternatives. On the other hand, environmental contaminants are equally present in foods of both origins. With regard to other food hazards, such as natural chemicals, microbial pathogens and mycotoxins, no clear conclusions can be drawn, although several interesting points can be highlighted. It is difficult, therefore, to weigh the risks, but what should be made clear to consumers is that 'organic' does not equal 'safe'. If producers adopt proper agricultural practices and consumers maintain hygienic conditions, risks associated with food contaminants can be minimised, regardless of the food's organic or conventional origin.