Mediterranean diet and cancer

OBJECTIVE: To analyse the role of various aspects of the Mediterranean diet in several common epithelial cancers, including digestive and selected non-digestive tract neoplasms. DESIGN: Systematic analysis of data from a series of case-control studies. SETTING: Northern Italy, between 1983 and 1998. SUBJECTS: Over 12,000 cases of 20 cancer sites and 10,000 controls. RESULTS: For most epithelial cancers, the risk decreased with increasing vegetable and fruit consumption, with relative risk (RR) between 0.3 and 0.7 for the highest versus the lowest tertile. For digestive tract cancers, population-attributable risks for low intake of vegetables and fruit ranged between 15 and 40%. A protective effect was observed also for breast, female genital tract, urinary tract and a few other epithelial neoplasms. A number of antioxidants and other micronutrients showed an inverse relationship with cancer risk, but the main components responsible for the favourable effect of a diet rich in vegetables and fruit remain undefined. Fish tended to be another favourable diet indicator. In contrast, subjects reporting frequent red meat intake showed RRs above unity for several common neoplasms. Intake of whole-grain foods was related to a reduced risk of several types of cancer, particularly of the upper digestive tract. This may be due to a favourable role of fibre, but the issue is still open to discussion. In contrast, refined grain intake and, consequently, glycaemic load and glycaemic index were associated with increased risk of different types of cancer including, among others, breast and colorectal. CONCLUSIONS: A low-risk diet for cancer in the Mediterranean would imply increasing the consumption of fruit and vegetables, as well as avoiding increasing the intakes of meat and refined carbohydrates. Further, olive oil and other unsaturated fats, which are also typical aspects of the Mediterranean diet, should be preferred to saturated ones.     

Mediterranean diet and cognitive decline

OBJECTIVE: To investigate the possible role of diet in age-related cognitive decline (ARCD) and cognitive impairment of both degenerative (Alzheimer's disease, AD) and vascular (vascular dementia, VaD) origin. DESIGN: Literature review. RESULTS: In an elderly population of southern Italy with a typical Mediterranean diet, high energy intake of monounsaturated fatty acids (MUFA) appeared to be associated with a high level of protection against ARCD. In addition, dietary fat and energy in the elderly seem to be risk factors, while fish consumption and cereals are found to reduce the prevalence of AD in European and North American countries. Finally, the relative risk of dementia (AD and VaD) was lower in the subjects of a French cohort who drank three or four glasses of red wine each day compared with total abstainers. CONCLUSION: Essential components of the Mediterranean diet--MUFA, cereals and wine--seem to be protective against cognitive decline. As such, dietary antioxidants and supplements, specific macronutrients of the Mediterranean diet, oestrogens and anti-inflammatory drugs may act synergistically with other protective factors, opening up new therapeutic interventions for cognitive decline.     

Mediterranean diet and overall mortality differences in the European Union

OBJECTIVE: To assess whether the Mediterranean diet contributes to overall mortality differences and trends between Mediterranean and non-Mediterranean European Union (EU) countries.Design: Routinely recorded adjusted overall mortality and food availability data in Mediterranean and non-Mediterranean EU countries. A Mediterranean diet score designed a priori was used as instrument. SETTING: Fifteen EU countries in the 1960s and the 1990s. SUBJECTS: The general population in the 15 EU countries. RESULTS: The difference between Mediterranean and non-Mediterranean EU countries in a 7-point Mediterranean diet score was reduced from 2.9 in the 1960s to 1.6 in the 1990s. This reduction may underlie the reduction in the difference in general mortality between these countries, from about 100 deaths per 100,000 person-years in the early 1970s to about 50 deaths per 100,000 person-years in the 1990s. CONCLUSIONS: The decline in overall mortality in the 15 EU countries over the last 25 years is probably unrelated to diet. However, the gradual loss of the survival advantage of Mediterranean EU citizens, compared with other EU citizens, may be linked to the gradual abandonment by the former of their dietary traditions.     

Traditional Mediterranean diet and longevity in the elderly: a review

OBJECTIVE: To review the evidence that the traditional Mediterranean diet is associated with longevity. SETTING: Elderly persons of both genders in Greece, Spain, Denmark and Australia studied by different groups of investigators. METHODS: Adherence to the principles of the Mediterranean diet was operationalised through a score devised a priori, and study participants were followed up until death or the end of the study. Proportional hazard models were used. RESULTS: Closer adherence to the Mediterranean diet was associated with a significant decrease in general mortality among the elderly persons studied. CONCLUSION: The Mediterranean diet is positively associated with longevity among the elderly. If the assumption holds that there is no interaction between age and diet with respect to general mortality, it can be inferred that the traditional Mediterranean diet represents a healthy nutritional pattern.     

Ageing and the Mediterranean diet: a review of the role of dietary fats

Consumers are becoming increasingly aware of the relationship between food and health. Concerns have been raised about dietary fats and their relative nutritional advantages or disadvantages. In investigations of the associations between health and fat intake, special emphasis has been placed on the benefits of virgin olive oil for counteracting certain neurodegenerative diseases and ageing. With respect to ageing, accumulating evidence indicates that an improvement in quality of life can be reached by modulation of the extrinsic factors that influence many ageing processes. Of the modifiable factors, nutrition appears to be one of the strongest elements known to influence the rate of ageing as well as the incidence of age-associated diseases such as atherosclerosis and neurodegenerative pathologies. This paper reviews the theory of ageing and the role of fatty acids in the mechanisms affecting its evolution. It also confirms that virgin olive oil, an essential component of the Mediterranean diet, provides large amounts of stable and not easily oxidizable fatty acids as well as remarkable quantities of powerful antioxidant molecules.     

Mediterranean diet in relation to body mass index and waist-to-hip ratio

OBJECTIVE: The Mediterranean diet is rich in fat and starch, and hence may be related to overweight. We therefore investigated the relationship between adherence to a Mediterranean diet and body mass index (BMI) and waist-to-hip ratio (WHR). DESIGN AND SETTING: Data were obtained from the control group of a network of case-control studies on cancer conducted in major teaching and general hospitals in four Italian areas between 1991 and 2002. An interviewer-administered validated 78-item food-frequency questionnaire was used to obtain information on the subjects' habitual diet. Information on socio-economic factors, lifestyle habits and anthropometric measures was also collected. A Mediterranean diet score (MDS) was derived on the basis of eight characteristics of the Mediterranean diet. SUBJECTS: Subjects were 6619 patients (3090 men, 3529 women) admitted to hospital for a wide spectrum of acute, non-neoplastic conditions, unrelated to known risk factors for cancer and long-term modifications of diet. RESULTS: In multiple linear regression models adjusted for age, study centre, education, tobacco smoking, occupational physical activity and total energy intake, the MDS was not related to BMI (beta = 0.05 for men and -0.04 for women) or WHR (beta = 0.000 and 0.001, respectively) in both sexes. CONCLUSIONS: Adherence to the major characteristics of the Mediterranean diet is unrelated to BMI and WHR, confirming previous data from Greece and Spain.     

Food, youth and the Mediterranean diet in Spain. Development of KIDMED, Mediterranean Diet Quality Index in children and adolescents

OBJECTIVE: To evaluate dietary habits in Spanish children and adolescents based on a Mediterranean Diet Quality Index tool, which considers certain principles sustaining and challenging traditional healthy Mediterranean dietary patterns. DESIGN: Observational population-based cross-sectional study. A 16-item Mediterranean Diet Quality Index was included in data gathered for the EnKid study (in which two 24-hour recalls, a quantitative 169-item food-frequency questionnaire and a general questionnaire about socio-economic, demographic and lifestyle items were administered). SETTING: Spain. SUBJECTS: In total, 3850 children and youths aged 2-24 years residing in Spain. RESULTS: Of the sample, 4.2% showed very low KIDMED index results, 49.4% had intermediate values and 46.4% had high index results. Important geographical differences were seen, with subjects from the Northeast showing the most favourable outcomes (52% with elevated scores vs. 37.5% of those from the North). Lower percentages of high diet quality were observed in low socio-economic groups, compared with middle and upper income cohorts (42.8%, 47.6% and 54.9%, respectively). Large cities had more positive results and only slight variations were seen for gender and age. CONCLUSIONS: The KIDMED index, the first to evaluate the adequacy of Mediterranean dietary patterns in children and youth, confirms that this collective is undergoing important changes, which makes them a priority target for nutrition interventions. Results challenge certain commonly perceived notions tied to income level, population size and diet quality.     

Wheat growth and yield responses to biochar addition under Mediterranean climate conditions

The effects of the addition of a slow pyrolysis biochar (produced from olive-tree prunings) to a vertisol were studied in a field experiment during one wheat (Triticum durum L.) growing season. The biochar addition did not significantly affect soil parameters such as pH, dissolved organic C and N, ammonium, nitrate or microbial biomass N. By contrast, biochar addition decreased soil compaction and increased the soil water-retention capacity and nutrient content (total N and the available contents of P, K, Mg, Cu and Zn). These favourable changes led to an increase in fine root proliferation (increasing specific root length and reducing root tissue density) and promoted crop development. As a result, the plants in biochar-treated plots showed higher relative growth and net assimilation rates, aboveground biomass and yield than those in control plots. Neither grain quality nor nutrient content were significantly affected by biochar addition. Our results suggest that the use of biochar as a soil amendment in agricultural soils can improve soil physical properties and increase fertility, favouring crop development under semiarid Mediterranean conditions.     

Nutrition education and Mediterranean diet: exploring the teaching process of a school-based nutrition and media education project in Cretan primary schools

BACKGROUND: During the past few decades there has been a gradual abandoning of the traditional Mediterranean diet by the population of Crete and especially among the younger generations. Since this is related to the rapidly increasing morbidity and mortality rates from chronic diseases, the need for educating young people on the principles of good nutrition becomes increasingly important. It is also acknowledged that the epidemiological field needs to focus on studying the implementation process, since this will allow for a deeper understanding of the outcomes. OBJECTIVES: The aims of the present study were to explore the process of implementing an innovation in Cretan primary schools and to identify best teaching practices and principles. DESIGN: In three state primary schools on the island of Crete, 107 children took part in a 30-h nutrition and media education programme. Classroom observations were used to define attitudes towards the programme and teaching methods. Besides baseline and post evaluation, the pupils were also interviewed about 11 months after the end of the programme. IMPLEMENTATION: During observation of the teaching process, emerging issues were the teacher's motivation and interest in the course, his/her preparation before each class, teaching ability and communication skills, the respect and discipline he/she kept and the innovative teaching methods used. In some cases researcher intervention in the classroom could not be avoided. FINDINGS AND CONCLUSIONS: Overall, individual teacher willingness and teaching skills were mainly responsible for the quality of teaching, the variety of educational methods used in classrooms and pupils' interest in the course. Changes in pupils' knowledge and recall of the course were related to teacher enthusiasm but also to researcher intervention. Exploring the teaching and learning process allowed a deeper understanding of the data. It is concluded that attempts to introduce the principles of a Mediterranean diet to children through nutrition education require innovative, enthusiastic and highly motivated teachers.     

堆肥提取液中腐殖酸类物质能够显著促进黄瓜生长

The effects of direct extracts of compost (DEC), aerated fermentation extracts of compost (AFEC) and non-aerated fermentation extracts of compost (NAFEC) on cucumber growth and the action mechanisms were evaluated based on the structure and activity analysis of humic-like substances. AFEC increased cucumber growth most significantly, followed by DEC and NAFEC, which was insignificant compared to the control treatment. Humic-like substances from compost extracts played an important role in promoting cucumber growth. Application of humic-like substances stimulated auxin-like activity and increased chlorophyll content and nitrogen accumulation in plants. The positive auxin-like activity of humic-like substances could be attributed to the relative distribution of special carbon groups, such as those with a large amount of peptidic and carbohydratic groups or with a low content of phenolic groups. In conclusion, the best growth promotion by application of AFEC was mainly attributed to the humic-like substances in the AFEC.     

Soil sterilisation and plant growth-promoting rhizobacteria promote root respiration and growth of sweet cherry rootstocks

Soil microorganisms play important roles in the plant-soil ecosystem, and plant growth-promoting rhizobacterium (PGPR) promotes plant growth through several mechanisms. To investigate the benefits of PGPR for root functions such as respiration, we used the plant model Cerasus sachalinensis Kom., in which root respiration provides a sensitive functional indicator to demonstrate the effect of soil sterilisation (SS) and inoculation with the PGPR Staphylococcus sciuri ss sciuri after SS on seedling root respiration and growth. Root respiration increased in the presence of PGPR inoculation alone, whereas Embden–Meyerhof–Parnas pathway activity decreased due to reduced phosphofructokinase and pyruvate kinase activities. Although cytochrome c oxidase activity decreased and alternative oxidase activity increased, only slight changes were observed in growth indicators such as seedling height. However, SS and PGPR inoculation after sterilisation reduced soil microbial biomass carbon and reduced root respiration. Pyruvate kinase activity as well as plant height and leaf number increased, thus promoting plant growth. Thus, we conclude that SS and PGPR inoculation altered enzymes activities, root respiration and plant growth of cherry rootstocks. The effects of microbial inoculation were altered by SS.     

Mediterranean natural forest living at elevated carbon dioxide: soil biological properties and plant biomass growth

Abstract. Biomass productivity and soil microbial responses to long-term CO₂ enrichment have been investigated in a Mediterranean natural forest ecosystem. Several biochemical parameters have been measured on soil samples taken from six open top chambers (OTCs), enclosing clumps of natural Mediterranean woody vegetation including: Quercus ilex L., Phillyrea angustifolia L., Pistacia lentiscus L. and Myrtus communis L. The CO₂ concentration of the air inside the OTCs was either ambient or ambient plus 350 μmol mol^–1 ( c . 710 ppm as mean daily value). Microbial C biomass, microbial respiration, dehydrogenase, β-glucosidase, acid phosphatase and protease activities, inorganic N and soluble P, were tested in order to evaluate soil microbial size and activity. Statistically correlated seasonal patterns have been identified in some biochemical parameters in response to climatic conditions, soil nutritional status and the physiology of the vegetative cover. In situ soil respiration and above- and below-ground productivity were also measured. Microbial responses to CO₂ enrichment were observed only at the beginning of the study and a general progressive reduction of the CO₂ effect was recorded as monitoring continued. These results are in agreement with data from literature regarding similar studies on natural complex communities.     

Bacteria able to control foot and root rot and to promote growth of cucumber in salinated soils

The aim of the present work was to test known bacterial plant growth-promoting strains for their ability to promote cucumber plant growth in salinated soil and to improve cucumber fruit yield by protecting these plants against soil-borne pathogens. Fifty-two plant-beneficial bacterial strains were evaluated for their ability to protect plants against cucumber foot and root rot after bacterization of the seeds and infestation of salinated soil with the isolated Fusarium solani pathogen. Based on the results of initial screenings, five efficient strains were selected, namely Serratia plymuthica RR-2-5-10, Stenotrophomonas rhizophila e-p10, Pseudomonas fluorescens SPB2145, Pseudomonas extremorientalis TSAU20, and P. fluorescens PCL1751. All five strains are salt tolerant since they grow well in a medium to which 3% NaCl was added. Infestation of the soil with F. solani resulted in an increase of the percentage of diseased plants from 17 to 54. Priming of seedlings with the five selected bacterial strains reduced this proportion to as low as 10%. In addition, in the absence of an added pathogen, all five strains showed a significant stimulatory effect on cucumber plant growth, increasing the dry weight of whole cucumber plants up to 62% in comparison to the non-bacterized control. The strains also increased cucumber fruit yield in greenhouse varying from 9% to 32%. We conclude that seed priming with the selected microbes is a very promising approach for improving horticulture in salinated soils. Moreover, allochthonous strains isolated from non-salinated soil, from a moderate or even cold climate, and from other plants than cucumber, functioned as well as autochthonous strains as cucumber-beneficial bacteria in salinated Uzbek soils. These results show that these plant-beneficial strains are robust and they strongly suggest they can also be used successfully in case the climate gets warmer and the soils will become more salinated. Finally, the mechanisms by which they may exert their plant-beneficial action are discussed.