Academic literature on the topic 'Mediterranean diet'

The Mediterranean diet is a food pattern incorporated into a set of lifestyle practices typical of Greece and Southern Italy in the early 1960s, where adult life expectancy was notably high, while rates of diet-related chronic diseases were low. The Mediterranean diet was described initially by the work of LG Allbaugh, commissioned by the Rockefeller foundation and the Greek government post-WW2 on the Greek island of Crete in 1948. The Mediterranean diet was accepted as Intangible Cultural Heritage of Humanity by UNESCO in 2013. The primary advantages of the Mediterranean diet include health benefits pertinent to cardiovascular, metabolic syndrome, and cognition.

AbstractObjectiveTo present the Mediterranean diet as an example of a sustainable diet, in which nutrition, biodiversity, local food production, culture and sustainability are strongly interconnected.DesignReview of notions and activities contributing towards the acknowledgement of the Mediterranean diet as a sustainable diet.SettingThe Mediterranean region and its populations.SubjectsMediterranean populations.Results and conclusionsThe acknowledgement of the Mediterranean diet as a sustainable diet needs the development of new cross-cutting intersectoral case studies to demonstrate further the synergies among nutrition, biodiversity and sustainability as expressed by the Mediterranean diet for the benefit of present and future generations.

This thesis engages with the problem of valuing the Intangible Cultural Heritage (ICH) of the Mediterranean Diet (MD), into the overall context of its progressive erosion due to general decline in adherence to the Mediterranean dietary pattern by Mediterranean people, especially young generations. This work is also engaged with the problem of what it may be done to preserve, safeguard and revitalize the ICH of the MD. In this context, with the double specific objective to calculate economic value of the Mediterranean Diet - Intangible Cultural Heritage and to define the specific determinants of respondents WTP for MD heritage and, consequently, for preserving it, a contingent valuation (CV) survey was conducted between July and October 2016, using nationwide internet-based interviews on a sample of 897 Italian respondents. To this scope, ICH of MD was declined in a prototypical project, which factoring the most affective elements of the intangible cultural heritage of the Mediterranean diet into a tangible product related with cultural as well as tourism sector: the “Mediterranean Diet District”. It was designed to let people, physically and actively, “experience” the ICH of the MD, making explicit and tangible its use value. The results of this study provide quantitative information and important insights for both policymaking and research.

Ketogenic diets (KDs) are diets in which the net carbohydrate intake, calculated by subtracting fibres from total carbohydrates, is between 20 and 50 g/day (<10% of total energy intake) with a variable proportion of proteins and fats (Noakes, Windt 2017). In these conditions, glycogen stores are depleted (Paoli, Canato et al. 2011), insulin level is low and energy metabolism is mainly dependent from fat oxidation. KDs lead a significant increase in circulating levels of ketone bodies (KBs) β-hydroxybutyrate (βOHB), acetoacetate (AcAc) and acetone (Veldhorst, Westerterp et al. 2010). While AcAc and βOHB are used as energy, acetone is a volatile compound and is eliminated through expiration, giving the “sweet” breath odour typical of ketosis, or via renal excretion (Paoli, Canato et al. 2011). The concentration of KBs in the blood of healthy individuals during the carbohydrate fed state is about 0.1 mmol/L and increases to about 0.3 mmol/L after an overnight fast, but after prolonged fasting up to 20 days KBs can increase to more than 10 mmol/L. A diet is considered “ketogenic” when produces a stable increase in the level of βOHB higher than 0.6 mmol/L (Wiggam, O'Kane et al. 1997) or when the molar ratio of blood glucose to blood ketone body βOHB is less than or equal to 1 (Meidenbauer, Mukherjee et al. 2015). Since KBs AcAc and βOHB are acids, the ketosis state implies a condition of acidosis. Given the fact that the pH of the blood is 7.4 and that the pKa of AcAc is 3.8 and that of βOHB is 4.8, these acids circulate in the blood in a completely dissociated form and are eliminated together with sodium and potassium ions (Siliprandi & Tettamanti 2011). This loss of cations implies a decrease of pH, which is normally balanced from the body apart when potassium and sodium intake are impaired (Phinney 2004) or in pathological overproduction of KBs during untreated diabetes type 1 which leads to diabetic ketoacidosis, characterized by a KBs level higher than 20 mmol/L with a decrease of pH. Biochemistry Hans Krebs was the first who diversified physiologic from pathologic ketosis (Krebs 1966). For skeletal and cardiac muscle, which usually oxidize fats, the use of KBs is a relative advantage, while for the central nervous system, in which the entrance of fatty acids is prevented from the blood-brain-barrier (BBB), the availability of KBs is an important surrogate of glucose, which is the habitual substrate of nervous tissue. During starvation, under a ketogenic diet or in new-born infants, the brain can utilize KBs as primary fuel instead of glucose (Laeger, Metges et al. 2010) in proportion to the degree of ketosis (Hartman, Gasior et al.). βOHB is the most abundant circulating ketone body and its transport across the blood-brain barrier is mediated both by diffusion and by several monocarboxylic acid transporters as MCT1 and MCT2, the former being upregulated during a ketogenic diet (Newman, Verdin 2014). This complementary action between the liver, which produces KBs in periods of shortage of carbs, and the CNS which use them, it’s a very important event which was determinant for the survival of the human species over the millennia. My research focused on three important aspects of KDs and weight loss, which needed further investigation: 1. long-term successful weight loss after a KD: the maintenance of weight loss over long time is challenging and the fear of weight regain is common, so that this phenomenon is named “yo-yo” effect. In this regard, low-carbohydrate diets are known to bring better results compared to low-fat diets in terms of weight loss (Shai, Schwarzfuchs et al. 2008) but not of compliance (Greenberg, Stampfer et al. 2009). Recently, Sumithran and colleagues have demonstrated that the increase in circulating ghrelin and in subjective appetite, which accompanied a hypocaloric diet, was reduced with a ketogenic approach (Sumithran, Prendergast et al. 2013). Thus, we hypothesized that certain aspects of the KD such as muscle mass retention, RMR (resting metabolic rate) and orexigenic hormone stability combined with the acknowledged health benefits of traditional Mediterranean nutrition may favour long-term weight loss. The aim of our study was to investigate the effect on weight and body composition of two short periods of a modified KD, i.e., a very low carbohydrate ketogenic diet with phytoextracts (KEMEPHY) (Paoli, Cenci et al. 2010, Paoli 2011, Paoli 2012) interspersed between longer periods of maintenance nutrition, based on the traditional Mediterranean diet, over a total period of 12 months in obese/overweight healthy subjects and was designed as a retrospective study. We analysed 89 male and female subjects, aged between 25 and 65 years who were overall healthy apart from being obese (mean BMI 35.82 ± 4.11 kg/m2). Data from this study demonstrate that the majority of subjects showed significant weight loss (10%) as a result of a two-phase KD and were compliant both during the six month weight loss phase and the six month normocaloric maintenance phase, with no weight regain. Moreover, the proposed protocol led improvements in health risk factors (total cholesterol, LDL cholesterol, triglycerides and glucose levels) in the majority of subjects. Compliance was very high which was a key determinant of the results seen; 2. formulation of new low-carbohydrate ultraprocessed foods to overcome the lack of sweet taste during a KD: a point of interest, which has always been a detrimental aspect of KDs, is the lack of sweet taste, which could be difficult to sustain for long periods, especially for people with a high sweet food preference. During consumption of a KD, it is mandatory to maintain a low level of glycaemia (about 80–90 mg/dL) to avoid insulin spikes (Paoli, Canato et al. 2011). This condition allows subjects to improve their fat oxidation as demonstrated by Paoli et al. (Paoli, Grimaldi et al. 2012) and by Tagliabue et al. (Tagliabue, Bertoli et al. 2012). Today the new food technology, which is able to build ultra-processed products very low in sugar content and high in protein and fibres, can help to solve this problem, formulating products with a high palatability and ready-to-consume format, useful both in ketosis and in easier low carb diets. Usually, ultra-processed products lack in proteins and fibres and produce postprandial glucose and insulin spikes (PAHO WHO 2015). This effect is known to elicit food craving and overeating, with a preference for high-glycaemic index carbohydrates (high-GI CHO) (Lennerz, Alsop et al. 2013), a phenomenon defined as CHO-craving effect (Ventura, Santander et al. 2014). In order to analyse the effect of 10 different high-protein low-CHO proprietary foods on glycaemia, we recruited 14 healthy females, which were tested for their glycaemic response through the glycaemic score (GS) method. All test foods, compared with glucose, produced a significantly lower glycaemic response and their GS resulted lower than 25 (compared to the reference GS value of glucose which is 100). We concluded that the reformulation of ultraprocessed ready-to-consume foods in a low-CHO, high-protein version can produce a significantly lower glycaemic response whilst maintaining the valued ready-to-use format and high palatability demanded by consumers, facilitating the adherence to a KD of individuals who tend to have a high preference for sweet foods; 3. effect of KDs on cognitive functions: the range of variation of glucose and ketone bodies (KBs) in the blood of non-diabetic individuals is wide and both of them can be used as energy from the brain. Data on glycaemia and ketonemia effects on cognitive functions on healthy humans following different diets are scarce. The purpose of this study was then to compare the effects of glycaemia and ketonemia variation after ten days of two different ketogenic diets and a calorie-restricted Mediterranean diet (MD) on working memory and executive functions in 63 sedentary healthy overweight (BMI>25) young women (age: 20-35), which were recruited in the university area. Subjects were divided in groups according to the day of the beginning of their follicular phase in order to minimize hormonal effects on mood and came for the basal measurements five days before the start of the dietary protocol. The following controls were set on the starting day of the diet (t1), on the third (t3), on the fifth (t5), on the seventh (t7) and on the last day (t10). On the basal control day, the weight of the subjects was measured and a body impedance analysis was performed. Subjects took a standard high carb breakfast and afterwards they completed the psychological tests. At t1, t3, t5, t7 and t10 ketone bodies levels and glycaemia were measured, as well as appetite levels. On the last control day (t10) subjects repeated the body impedance analysis, the body weight measure and, after breakfast (each group had a different breakfast according to the prescribed diet), the psychological tests. Psychological tests consisted in a mood test, two cognitive tasks, one to investigate working memory (visuo-spatial n back) and the second to stress executive functions (inhibitory control task) and in a VAS scale to test the appetite level. 45 subjects completed the study. Considering all participants together, pre-diet glucose levels were positively correlated with reaction time in the go-trial of the executive function test (r(43) = 0.358, p = 0.018), but this relation was not found in the post-diet measure both when subjects were analysed all together and when subjects were divided according to the type of diet followed. In the same psychological test, in the post-diet measure ketonemia showed a negative correlation with accuracy of the no-go trials (r(29) = -0.455, p = 0.027). We can conclude that healthy young overweight subjects with fasting glycaemia below prediabetes level were negatively affected by a high-carb breakfast during an executive function test. Moreover, the effect of mild KBs levels (2 ± 1.3 mmol/L) negatively affected accuracy of the no-go trials of the executive functions test.
Le diete chetogeniche sono diete in cui l’introito netto di carboidrati, calcolato sottraendo la quantità di fibre dai carboidrati totali, è tra 20 e 50 g/gg (<10% dell’apporto energetico totale) con una proporzione variabile di proteine e grassi (Noakes, Windt 2017). In queste condizioni le riserve di glicogeno sono esaurite (Paoli, Canato et al. 2011), il livello di insulina è basso e il metabolismo energetico dipende prevalentemente dall’ossidazione dei grassi. Le diete chetogeniche portano un aumento significativo dei livelli circolanti dei corpi chetonici β-idrossibutirrato, acetoacetato e acetone (Veldhorst, Westerterp et al. 2010). Mentre sia l’acetoacetato che il β-idrossibutirrato vengono utilizzati come energia, l’acetone è volatile ed è eliminato attraverso l’espirazione, dando all’alito quella nota “fruttata” tipica della chetosi, oppure attraverso i reni (Paoli, Canato et al. 2011). La concentrazione ematica dei corpi chetonici in individui sani che seguono una dieta costituita prevalentemente da carboidrati è 0,1 mmol/L e può salire fino a 0,3 mmol/L dopo il digiuno notturno, ma dopo venti giorni di digiuno il livello di corpi chetonici può salire oltre 10 mmol/L. Una dieta è considerata “chetogenica” quando produce un aumento del livello di β-idrossibutirrato superiore a 0,6 mmol/L (Wiggam, O'Kane et al. 1997) oppure se il rapporto molare tra il glucosio e il β-idrossibutirrato ematici è uguale o minore di 1 (Meidenbauer, Mukherjee et al. 2015). Dato che i chetoni acetoacetato e β-idrossibutirrato sono acidi, lo stato di chetosi implica una condizione di acidosi. Siccome il pH del sangue è 7,4 e la pKa dell’acetoacetato è 3,8 e quella del β-idrossibutirrato è 4,8, questi acidi circolano nel sangue in forma dissociata e sono eliminati insieme agli ioni sodio e potassio (Siliprandi & Tettamanti 2011) . Questa perdita di cationi porta una diminuzione del pH che viene normalmente tamponata dal corpo tranne quando l’assunzione di sodio e potassio è impedita (Phinney 2004) oppure in caso di diabete scompensato, quando c’è una sovrapproduzione di corpi chetonici con livelli superiori a 20 mmol/L e conseguente riduzione del pH. Il biochimico Hans Krebs fu il primo a distinguere la chetosi fisiologica da quella patologica (Krebs 1966). Per i muscoli scheletrici e cardiaco, che utilizzano normalmente i grassi, l’utilizzo dei corpi chetonici a scopo energetico è un vantaggio relativo, mentre per il sistema nervoso centrale, in cui l’accesso degli acidi grassi è impedito dalla barriera ematoencefalica, la disponibilità dei corpi chetonici è un importante surrogato del glucosio, che è il substrato abituale dei neuroni. Durante il digiuno, in dieta chetogenica e nei neonati, il cervello utilizza i corpi chetonici come combustibili principali al posto del glucosio (Laeger, Metges et al. 2010), proporzionalmente al grado di chetosi (Hartman, Gasior et al.). Il β-idrossibutirrato è il principale corpo chetonico circolante e il suo trasporto attraverso la barriera ematoencefalica avviene sia mediante diffusione che attraverso i trasportatori MCT1 e MCT2, dei quali i primi aumentano durante una dieta chetogenica (Newman, Verdin 2014). Quest’azione complementare tra il fegato, che produce i corpi chetonici in assenza di carboidrati, e il sistema nervoso centrale che li può utilizzare, è un evento molto importante che fu determinante per la sopravvivenza della specie umana nei millenni. La mia ricerca si è focalizzata su tre importanti aspetti delle diete chetogeniche - connesse alla perdita di peso - che richiedevano di essere approfonditi: 1. il mantenimento del peso perso dopo una dieta chetogenica: il mantenimento del peso perso a lungo nel tempo è impegnativo e la paura di ritornare velocemente al peso iniziale è comune, tanto che questo fenomeno viene chiamato “effetto yo-yo". A questo proposito, le diete a basso contenuto di carboidrati sono note per portare risultati migliori rispetto alle diete a basso contenuto di grassi in termini di perdita di peso (Shai, Schwarzfuchs et al. 2008c), ma non di “compliance” (adesione al protocollo) (Greenberg, Stampfer et al. 2009). Recentemente, Sumithran e collaboratori hanno dimostrato che l'aumento dei livelli circolanti di grelina e del livello di appetito tipici di una dieta ipocalorica erano minori durante un protocollo chetogenico (Sumithran, Prendergast et al. 2013). Abbiamo quindi ipotizzato che alcuni aspetti della dieta chetogenica come il mantenimento della massa muscolare, del metabolismo energetico basale e la stabilità del principale ormone oressigenico (grelina) combinati con gli effetti benefici della nutrizione tradizionale mediterranea, potessero favorire la perdita di peso a lungo nel tempo. Lo scopo del nostro studio è stato quindi quello di indagare l'effetto sul peso e sulla composizione corporea di due brevi periodi di una dieta chetogenica modificata, cioè una dieta fitochetogenica mediterranea (KEMEPHY) (Paoli, Cenci et al. 2010a, Paoli 2011, Paoli 2012) intervallata da 2 periodi più lunghi di dieta di mantenimento basata sulla dieta mediterranea tradizionale per un periodo totale di 12 mesi. I soggetti reclutati erano obesi o in sovrappeso e lo studio è stato retrospettivo. Abbiamo analizzato 89 soggetti (uomini e donne) di età compresa tra i 25 e i 65 anni che erano in uno stato di buona salute generale benchè fossero obesi (IMC medio 35.82 ± 4.11 kg/m2). I risultati di questo studio hanno dimostrato che la maggioranza dei soggetti ha ottenuto una significativa perdita di peso (10%) a seguito delle due fasi di dieta chetogenica e l’aderenza al protocollo è stata alta sia durante i sei mesi di perdita di peso sia nei successivi sei mesi di mantenimento, senza riacquisto del peso. Inoltre, il protocollo proposto ha portato miglioramenti nella maggior parte dei soggetti dei livelli di parametri importanti per la salute (colesterolo totale, colesterolo LDL, trigliceridi e livelli di glucosio). L’alta “compliance” è stato un fattore determinante per i risultati ottenuti; 2. la formulazione di nuovi prodotti a basso contenuto di carboidrati per sopperire alla mancanza del sapore dolce durante una dieta chetogenica: un aspetto delle diete chetogeniche difficile da tollerare nel lungo tempo, soprattutto per chi ha una spiccata preferenza per i dolci, è la mancanza di questo sapore. In dieta chetogenica è necessario mantenere un basso livello di glicemia (circa 80-90 mg/dL) per evitare i picchi di insulina (Paoli, Canato et al. 2011) e permettere così ai soggetti di migliorare l'ossidazione dei grassi come dimostrato da Paoli et al. (Paoli, Grimaldi et al. 2012) e da Tagliabue et al. (Tagliabue, Bertoli et al. 2012). Oggi la nuova tecnologia alimentare, che è in grado di costruire prodotti ultra-processati con un contenuto di zucchero molto basso e un alto contenuto di proteine e fibre, può aiutare a risolvere questo problema, formulando prodotti di elevata appetibilità in un formato pronto per il consumo, utili sia in chetosi che in diete ipoglucidiche più moderate. Di solito i prodotti ultra-processati mancano di proteine e fibre e producono picchi post-prandiali di glucosio e insulina (OPS WHO 2015) . Questo effetto provoca un forte desiderio di cibo con una preferenza per i carboidrati ad alto indice glicemico (Lennerz, Alsop et al. 2013), fenomeno definito come "carb-craving" (Ventura, Santander et al. 2014). Al fine di analizzare l'effetto di 10 diversi alimenti ultra-processati ad alto contenuto proteico e basso contento di carboidrati sulla glicemia, abbiamo reclutato 14 donne sane e abbiamo testato la loro risposta glicemica attraverso il metodo del punteggio glicemico (“glucose-score”, GS). Tutti gli alimenti testati hanno prodotto, rispetto al glucosio, una risposta glicemica significativamente inferiore e il loro GS è risultato inferiore a 25 (rispetto al valore di riferimento del GS del glucosio che è 100). Abbiamo quindi concluso che la riformulazione di prodotti ultra-processati pronti al consumo in una versione ad alto contenuto proteico e basso contenuto di carboidrati è in grado di produrre una risposta glicemica significativamente più bassa, pur mantenendo l'alto valore del pratico formato pronto per l'uso e l'alta appetibilità richiesta dai consumatori, facilitando quindi l'adesione a una dieta chetogenica di individui che tendono ad avere una forte preferenza per i cibi dolci; 3. l’effetto delle diete chetogeniche sulle funzioni cognitive: il range di variazione della glicemia o dei corpi chetonici nel sangue di soggetti non diabetici è ampia e ciascuno di essi può essere utilizzato come energia dal cervello. I dati sugli effetti della variazione dei livelli di glicemia e chetonemia sulle funzioni cognitive di esseri umani sani dopo diversi tipi di dieta sono scarsi. Lo scopo di questo studio è stato confrontare gli effetti della variazione di glicemia e chetonemia dopo dieci giorni di due differenti diete chetogeniche e di una dieta mediterranea ipocalorica (MD) sulla memoria di lavoro e sulle funzioni esecutive in 63 giovani donne sovrappeso, sedentarie e in buona salute (IMC> 25, età: 20-35) che sono state reclutate nella zona universitaria. I soggetti sono stati divisi in gruppi in base al giorno di inizio della loro fase follicolare per minimizzare gli effetti ormonali sull'umore e le misurazioni basali sono state effettuate cinque giorni prima dell'inizio del protocollo dietetico. I seguenti controlli sono stati fissati al giorno di inizio della dieta (t1), al terzo (t3), al quinto (t5), al settimo (t7) e all'ultimo giorno (t10). Al controllo iniziale è stato misurato il peso dei soggetti ed è stata eseguita un'analisi impedenziometrica. I soggetti hanno poi assunto una colazione ad alto contenuto di carboidrati e hanno completato i test psicologici. Al t1, T3, T5, T7 e t10 sono stati misurati il livello dei corpi chetonici e la glicemia, così come i livelli di appetito. Nel giorno dell'ultimo controllo (T10) i soggetti hanno ripetuto l'analisi impedenziometrica, la misura del peso corporeo e, dopo la colazione (ogni gruppo ha assunto una colazione diversa a seconda della dieta prescritta), hanno completato i test psicologici. I test psicologici consistevano in un test sull'umore, due compiti cognitivi, uno per indagare la memoria di lavoro (“visuo-spatial n back”) e uno per analizzare le funzioni esecutive (“inhibitory control task”) e in una scala VAS per testare il livello di appetito. 45 soggetti hanno completato lo studio. Considerando tutti i partecipanti insieme, i livelli di glucosio pre-dieta correlavano positivamente con il tempo di reazione nel “go-trial” del test delle funzioni esecutive (r(43) = 0,358, p = 0,018), ma questa relazione non è stata trovata nel post-dieta, sia quando i soggetti sono stati analizzati tutti insieme che quando i soggetti sono stati divisi in base al tipo di dieta seguita. Nello stesso test psicologico, nel post-dieta la misura della chetonemia ha mostrato una correlazione negativa con l'accuratezza ai compiti “no-go” (r(29) = -0,455, p = 0,027). Possiamo quindi concludere che giovani soggetti in sovrappeso con livelli di glicemia inferiori al livello di pre-diabete sono stati influenzati negativamente da una colazione ad alto contenuto di carboidrati nel corso di un test di funzioni esecutive. Inoltre, l'effetto di moderati livelli di corpi chetonici (2 ± 1,3 mmol / L) ha nfluenzato negativamente l'accuratezza nelle prove “no-go” del test sulle funzioni esecutive.

The United Kingdom is experiencing an ageing population. Currently one sixth of the UK’s population is aged over 65 years and this is estimated to rise to one quarter by 2050. There is considerable inter-individual variation in human lifespan and much of this variation appears to be due to non-genetic factors, including lifestyle. Both observational and intervention studies indicate that adherence to a Mediterranean dietary pattern is associated with increased lifespan and reduced risk of age-related disease. The LiveWell Programme was established to develop and pilot lifestyle-based interventions (including promoting a Mediterranean diet) to enhance healthy ageing, which could be delivered to individuals in the retirement transition. The aim of this PhD was to test age-appropriate dietary assessment methods suitable for measuring change in adherence to a Mediterranean diet, as a consequence of lifestyle-based interventions. Six different approaches for estimating Mediterranean diet scores (MDS) were applied to dietary data from the Mediterranean Diet in Northern Ireland (MEDDINI) intervention study. Based on the number of assumptions and modifications that were made to calculate the scores, the percentage change in diet between intervention groups and the coefficient of variation from baseline to follow up, the relative Mediterranean diet score (rMED) was identified as the most suitable score for testing the efficacy of intervention studies in a UK context. The next stage of the work was to investigate the utility of INTAKE24, an online 24 hour recall, as a method for assessing the diet of retirement-age adults. INTAKE24 is a self-completed dietary assessment tool which was developed originally for use with young people. This was the first time that this tool was used with older people and so it was essential to undertake user-testing and estimation of relative validation. The system usability was rated as above average by the majority of users. Of the food items recorded in INTAKE24, 87% of the foods recorded during user-testing and 84% of the food items recorded during relative validation, either exactly or approximately matched foods iii recorded in a comparable interviewer-led 24 hour recall. No significant differences in nutrient intakes or adherence to the Mediterranean diet (assessed by the rMED) were found between the two dietary assessment methods for either the user-testing or the relative validation study. In conclusion, INTAKE24 was well-received and assessed the diets of older adults well when compared with a conventional approach. However, further modifications of INTAKE24 (detailed within my thesis) would improve the usability and accuracy of the system for future studies involving older adults. In addition, the rMED method of scoring adherence to the Mediterranean dietary pattern is compatible with data collected using INTAKE24 and appears suitable for use in future dietary intervention studies with adults in the retirement transition.

The Mediterranean diet (Medi) has been highlighted as the golden diet rich in protective properties associated with cognitive- and emotional health. The foundation of the Medi comprises vegetables, fruits, nuts and seeds, legumes, and extra virgin olive oil. Research has been conducted in both holistic dietary approach and single nutrient approach regarding the impact of nutrition and diet, in this case, the Medi‟s effect on brain health. This review aims to give an up to date overview of the Mediterranean diet, outline some of the diet's abundant nutrients, and discuss studies linking the nutrient's potential effect on depression, cognitive decline, dementia, and brain structure and function. In addition, this review will attempt to assess whether the Medi as a whole or if a single nutrient approach is accountable for the health-promoting findings. Furthermore, the gut-brain axis, and other potential underlying mechanisms involved in the modulation of food- and nutrient intake and their effects on the brain, will be outlined. A diet high in fruit-, vegetable-, polyunsaturated fatty acid-, and monounsaturated fatty acid content has great power for health-maintenance and decreases the risk of suffering cognitive decline, dementia, and potentially depression. More randomized controlled trials are however eagerly awaited to give more substance to previous findings.

This thesis aimed to assess the feasibility of peer support (PS) for encouraging adoption and maintenance of a Mediterranean diet (MD) in a Northern European population at high CVD risk. It consists of (i) a systematic review of the effect of PS in encouraging dietary change in adults; (ii) qualitative analysis of barriers to a MD in a Northern European population; (iii) validation of a Mediterranean diet score (MDS) to assess MD adherence in a Northern European population and (iv) development and interim-analysis of a pilot RCT to assess the effectiveness of PS for encouraging MD adoption and maintenance in a Northern European population at high CVD risk (TEAM-MED study). The systematic review found that more studies reported a positive effect of PS or mixed results, than studies that did not find an effect of PS for achieving dietary change. However, as evidence was mixed, the effect of PS in encouraging dietary change in adults is not clear and further information is needed. Individuals at high risk of CVD from a Northern European population showed preference towards a group based PS model which was developed for assessment in the TEAM-MED study. Qualitative research among this population indicated a limited knowledge of, and a number of barriers towards consuming a MD which were addressed in the development of the TEAM-MED study. Validation of the TEAM-MED study MDS deemed this to be a reliable tool for assessing MD adherence among Northern European populations. The TEAM-MED study interim-analysis demonstrated that there was no significant difference in MD adherence between the PS, minimal and proven intensive intervention groups. Full analysis of the TEAM-MED study will confirm these results. While evidence is not yet clear, PS has the potential to encourage dietary change towards a MD in Northern European populations.

A 6-month intervention study with a quasi-experimental design and a 3-month follow-up was conducted to evaluate the effectiveness of an Internet-based, step-wise, tailored-feedback intervention promoting four key components of the Mediterranean diet (vegetables, fruits, nuts and seeds, legumes and ratio of monounsaturated to saturated fat). Fifty-three (intervention group) and nineteen (control group) healthy females, aged 25-55 years, were recruited from the Universities of Glasgow and Glasgow Caledonian, Scotland, respectively. Participants in the intervention group received tailored dietary and psychosocial feedback and Internet nutrition education over a 6-month period, while participants in the control group were provided with minimally-tailored dietary feedback and general healthy-eating brochures. Internet education was provided via an innovative Mediterranean Eating website. Between group comparisons carried out on an "intention-to-treat" basis, providing the strongest evidence of the effect of the intervention, showed that participants in the intervention group had made more favourable changes to their fruit, nut and seed intake over the 6-month intervention, as well as increased their vegetable intake over the 9-month trial. Over both the 6-month intervention and 9-month trial, participants in the intervention group had more favourable levels of HDL-cholesterol and ration of total:HDL-cholesterol, a higher proportion progressed through the stages of behavioural change regarding legumes and olive intake and self-efficacy skills were generally increased, compared with the control group. Participants in the control group however, showed more favourable urinary electrolyte levels throughout the study. Within group comparisons showed that at 6 months, participants in the intervention group had significantly increased their intake of vegetables, fruits, legumes, as well as the MUFA:SFA ratio in their diet, had increased their mean total MDS and had significantly increased plasma HDL-cholesterol levels and a reduced ratio of total:HDL-cholesterol, as well as higher nutrition knowledge scores compared with baseline. In addition, a higher percentage of participants in this group were in the action and maintenance stage of behavioural change for vegetables, legumes and olive oil consumption, as well as generally showing more favourable attitudes and self-efficacy skills towards consumption of most of the food components promoted by the study at 6 months. These changes were generally maintained at 9 months, when additional decreases in blood pressure and an increase in total cholesterol, compared with baseline, were reported. Participants in the control group increased their intake of legumes, as well as their mean total MDS, and had significantly reduced urinary sodium levels at 6 months, compared with baseline. In addition, a higher efficacy skills generally decreased, compared with baseline. These changes were not maintained at 9 months, but at this time point participants in this group had a higher nutrition knowledge score, compared with baseline.

Objective: The Mediterranean-Style Diet (MedD) pattern is associated with lower risk for chronic diseases. Key components to the MedD pattern are consumption of olive oil, green leafy vegetables, and fatty fish, all sources of omega-3 (O-3) fatty acids. The purpose of this study is to predict alignment to a MedD pattern using O-3 containing foods. Methods: A sample of 19,978 25-65 year olds with two reliable 24-hour recalls was obtained from the 2007-2018 National Health and Nutrition Examination Surveys. Multiple regression analyses determined differences by adherence level, high scorers (HS) vs. general population (GP), to the MedD pattern for dietary outcomes. Using isocaloric food substitution modeling within the GP, changes in MedD score were measured. Exclusive olive oil (OO) use was reported at 0.3% in GP; if OO use increased to half of oil as OO, MedD score would increase by 2.1 points. MedD score increased by 0.56 when replacing 4 oz. red meat for 4 oz. fish in the GP and 6.26 when replacing 0.67 cups starchy vegetables with 2 cups non-starchy vegetables. Conclusions: Increasing oil consumption to include half of oils from OO, replacing 4 oz of red meat with 4 oz of fatty fish, and replacing 0.67 cups starchy vegetables with 2 cups of non-starchy vegetables would help the GP to achieve better alignment to a MedD pattern.

The Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), is a ubiquitous pest of fruit trees, causing significant economic damage both in the U.S. and in Israel. Control efforts in the future will rely heavily on the sterile insect technique (SIT). Success of such operations hinges on the competitive ability of released males. The mating system of the medfly is based on leks. These are aggregations of sexually signaling males that attract females (who then select and copulate a courting male). A major component of male competitiveness is their ability to join existing leks or establish leks that are attractive to wild females. Accordingly, we identified leks and the behaviors associated with them as critical for the success of SIT operations. The objectives of this proposal were to determine 1. what makes a good lek site, 2. what are the energetic costs of lekking, 3. how females choose leks, and finally 4. whether the copulatory success of sterile males may be manipulated by particular pre-release diets and judicious spatial dispersal. We established that males choose lek sites according to their spatial location and penological status, that they avoid predators, and within the lek tree choose the perch that affords a compromise between optimal signalling, micro-climatic conditions and predation risk (Kaspi & Yuval 1999 a&b; Field et al 2000; Kaspi & Yuval submitted). We were able to show that leks are exclusive, and that only males with adequate protein and carbohydrate reserves can participate (Yuval et al 1998; Kaspi et al 2000; Shelly et al 2000). We determined that females prefer leks formed by protein fed, sexually experienced males (Shelly 2000). Finally, we demonstrated that adding protein to the diet of sterile males significantly enhances their probability of participating in leks and copulating wild females (Kaspi & Yuval 2000).

Food is an essential to our existence but under certain conditions it could become the origin to the accumulative health damages. Technological processes as heating, chopping, mincing, grounding, promote the lipid oxidation process in muscle tissues and meat foodstuffs. Lipid oxidation occurred rapidly in turkey muscle, intermediate in duck, and slowest in chicken during frozen storage. Depletion of tocopherol during frozen storage was more rapid in turkey and duck compared to chicken. These processes developed from lipid peroxides produce many cytotoxic compounds including malondialdehyde (MDA). The muscle tissue is further oxidized in stomach conditions producing additional cytotoxic compounds. Oxidized lipids that are formed during digestion of a meal possess the potential to promote reactions that incur vascular diseases. A grape seed extract (1% of the meat weight) and butylated hydroxytoluene (0.2% of the lipid weight) were each effective at preventing formation of lipid oxidation products for 3 hours during co-incubation with cooked turkey meat in simulated gastric fluid (SGF). Polyphenols in the human diet, as an integral part of the meal prevent the generation and absorption of cytotoxic compounds and the destruction of essential nutrients, eg. antioxidants vitamins during the meal. Polyphenols act as antioxidants in the gastrointestinal tract; they scavenge free radicals and may interact with reactive carbonyls, enzymes and proteins. These all reactions results in decreasing the absorption of reactive carbonyls and possible other cytotoxic compounds into the plasma. Consumptions of diet high in fat and red meat are contributory risk factors partly due to an increase production of cytotoxic oxidized lipid products eg. MDA. However, the simultaneously consumption of polyphenols rich foods reduce these factors. Locating the biological site of action of polyphenols in the in the gastrointestinal tract may explain the paradox between the protective effect of a highly polyphenols rich diet and the low bioavailability of these molecules in human plasma. It may also explain the "French paradox" and the beneficial effect of Mediterranean and Japanese diets, in which food products with high antioxidants content such as polyphenols are consumed during the meal.

Trees and shrubs are potentially important sources of food for livestock in many parts of the world, but their use is limited by tannins. Tannins reduce food intake by decreasing digestibility or by causing illness. Supplementing cattle, sheep, and goats with polyethylene glycol (PEG), which has a high affinity for binding tannins and thus attenuating their aversive effects, increases intake of high-tannin foods and improves weight gains and wool growth. The objectives of this proposal were: Objective 1: To further delineate the conditions under which PEG affects intake of high-tannin foods. Objective 2: To ascertain if animals self-regulate intake of PEG in accord with the tannin content of their diet under pen, paddock, and field conditions. Objective 3: To determine how nutritional status and PEG supplementation affect preference for foods varying in nutrients and tannins. Objective 4: To assess the effects of PEG on food selection, intake, and livestock performance in different production systems. The results from this research show that supplementing livestock with low doses of PEG increases intake of high-tannin foods and improves performance of cattle, sheep, and goats. Neutralizing the effects of tannins with supplemental PEG promotes the use of woody species usually considered useless as forage resources. Supplementing animals with PEG has the potential to improve the profitability - mainly milk production - of high-yielding dairy goats fed high-quality foods and supplemented with browse in Mediterranean areas. However, its contribution to production systems utilizing low-yielding goats is limited. Our findings also support the notion that supplemental PEG enhances the ability of livestock to control shrub encroachment and to maintain firebreaks. However, our work also suggests that the effectiveness of supplemental PEG may be low if alternative forages are equal or superior in nutritional quality and contain fewer metabolites with adverse effects.