Fatty acid activated membrane receptor function and fat in the nutritional prevention of diabetes type 2

The mechanisms of intracellular free fatty acid (FFA) effects on insulin secretion and signaling are known for many years, however, their effects exerted by extracellular route, via membrane receptors, have been recognized only recently. There are two main groups of membrane receptors activated by FFA: Toll like receptors (TLRs) engaged in nonspecific immunity, activated by bacterial and viral antigens and Gprotein coupled receptors (GPRs). Activation of TLR2 and 4 by saturated acids leads to activation of NFkB and induction of proinflammatory cytokines. Knockout of TLR2 or TLR4 protects from the effects of high fat diet — insulin resistance and beta-cell dysfunction. GPRs mediate insulinotropic effects of FFA exerted either directly on pancreatic beta cells (GPR- 40) or indirectly, in enteroendocrine cells, by stimulation of GLP-1 and GIP release (GPR-120). The effects of cholecystokinin, GLP-1 and GIP secretion through GPR-120 activation were shown for monounsaturated and polyunsaturated omega 3 fatty acids. In adipose tissue omega 3 fatty acids counteract the proinflammatory cytokine signaling and their synthesis. Short chain fatty acids utilize adipose GPR-43 for stimulation of leptin secretion and GPR-42 and 43 for stimulation of PYY and serotonin secretion by enteroendocrine cells. The intensive research of GPR ligands pharmacologically efficient in diabetes type 2 therapy are currently conducted. Comprehensive characterization of the effects of dietary fatty acids on GPR activation could enable the optimization of nutritional prevention and management of diabetes type 2. (Diabet. Prakt. 2011; 12, 2: 42–51)Od dawna są znane mechanizmy wewnątrzkomórkowego wpływu kwasów tłuszczowych na wydzielanie insuliny i jej działanie w tkankach docelowych. Od kilku lat natomiast poznaje się efekty wywierane przez kwasy tłuszczowe za pośrednictwem receptorów błonowych. Wykorzystywane przez kwasy tłuszczowe receptory błonowe to głównie zaangażowane w reakcje odporności nieswoistej receptory Toll-like (TLR) i receptory sprzężone z białkiem G (GPRs). Konsekwencjami aktywacji TLRs przez kwasy nasycone są uaktywnienie NFkB i indukcja ekspresji prozapalnych cytokin. Usunięcie genu TLR2 lub TLR4 chroni przed efektami wysokotłuszczowej diety — powstawaniem insulinooporności i dysfunkcji komórek beta w trzustce. Białka GPRs pośredniczą w insulinotropowym działaniu kwasów tłuszczowych wywieranym albo bezpośrednio na komórki beta trzustki (GPR-40), albo za pośrednictwem stymulacji wydzielania GLP-1 i GIP przez komórki enteroendokrynne (GPR-120). Stymulujący wpływ na wydzielanie za pośrednictwem GPR-120 cholecystokininy, GLP-1 i GIP wykazano dla kwasów jednonienasyconych i wielonienasyconych omega 3. Kwasy tłuszczowe omega 3, wiążąc się w tkance tłuszczowej z GPR-120, hamują przeniesienie sygnału cytokin prozapalnych oraz ich syntezę. Kwasy tłuszczowe krótkołańcuchowe za pośrednictwem GPR-43 stymulują wydzielanie leptyny, a wiążąc się z GPR-42 i -43 — wydzielanie PYY i serotoniny przez komórki enteroendokrynne. Prowadzi się intensywne badania w celu znalezienia sztucznych ligandów GPR i ich farmakologicznego wykorzystania w terapii cukrzycy typu 2. Dokładne scharakteryzowanie wpływu kwasów tłuszczowych diety na aktywację GPR może pozwolić na wprowadzenie odpowiednich zmian w profilaktyce i terapii żywieniowej cukrzycy typu 2. (Diabet. Prakt. 2011; 12, 2: 42–51

Natural and synthetic modulators of sirtuin activity

Sirtuiny należą do rodziny deacetylaz histonów zależnych od NAD. Ich substratami jest wiele enzymów i czynników transkrypcyjnych, a kontrolując ich aktywność sirtuiny uczestniczą w utrzymaniu homeostazy ustroju. Sirtuiny mogą ograniczać rozwój schorzeń związanych z wiekiem, w tym nowotworów. Ich aktywność modulowana jest przez wiele czynników żywieniowych. Restrykcja kaloryczna oraz niektóre aminokwasy przyczyniają się do wzrostu aktywności sirtuin. Natomiast nadmierne spożycie tłuszczu i węglowodanów hamuje ich aktywność. Naturalnymi aktywatorami sirtuin, występującymi w żywności są niektóre związki z grupy flawonoli, katechin, alkaloidów oraz izoflawonów. Aktualnie trwają prace nad znalezieniem nowych syntetycznych aktywatorów sirtuin. Ze względu na potencjalny udział niektórych sirtuin w patogenezie chorób neurodegeneracyjnych poszukuje się inhibitorów tych enzymów.Sirtuins belong to the family of NAD-dependent histone deacetylases. Sirtuin substrates include a great number of enzymes and transcription factors. In this way sirtuins regulate homeostasis of the whole organism. Sirtuins can limit the development of age-related diseases, including cancers. Their activity is modulated by many nutritional factors. Caloric restriction and some amino acids contribute to sirtuins stimulation. Excessive intake of fat and carbohydrates inhibits their activity. Daily diet includes natural sirtuin activators such as flavanoles, catechins, alcaloids and isoflavonoids. Currently, new synthetic activators of sirtuins are under investigations. In view of possible involvement of some sirtuins in pathogenesis of neurodegenerative diseases, search for inhibitors of this class of enzymes is of particular importance

Lipid and thyroid hormone interactions

Relacje między działaniem hormonów tarczycy i związków lipidowych, kwasów tłuszczowych, eikozanoidów i steroli, stanowią ważny element utrzymania homeostazy energetycznej ustroju. Hormony tarczycy wpływają na syntezę i utlenianie kwasów tłuszczowych, syntezę cholesterolu, jego wychwyt i transport odkomórkowy. Tłuszcz diety z kolei, w zależności od ilości i składu, zmienia funkcjonowanie elementów osi podwzgórzowo-przysadkowo-tarczycowej. Jądrowe receptory T3 i czynniki transkrypcyjne wiążące związki o charakterze lipidowym są zaangażowane w regulację ekspresji tych samych genów, wykazują znaczne podobieństwa strukturalne, w tym miejsc wiązania DNA i sekwencji wiążących w DNA. Wszystkie te receptory tworzą heterodimery z receptorami kwasu 9-cis-retinowego, RXR. Występują między nimi zarówno reakcje współdziałania, jak i antagonizmu. Receptor aktywowany przez proliferatory peroksysomalne typu γ wpływa na różnicowanie komórek tarczycy i hamuje procesy zapalne w gruczole.Relationships between thyroid hormone and lipid compounds: fatty acids, eicosanoid and sterol actions are important for the energy homeostasis. Thyroid hormones affect the fatty acid synthesis and oxidation, cholesterol synthesis and its cellular uptake as well as the reverse transport. In turn, dietary fat in the manner depending on its amount and composition alters the hypothalamus-pituitary-thyroid axis activity. Nuclear thyroid hormone receptors and transcriptional factors binding lipid compounds regulate expression of the same genes, share structural similarities in the DNA binding domains and responsive element. All these receptors form the heterodimers with 9-cis-retinoic acid, RXR. Their interactions include both synergy and antagonism. Proliferator activated receptor type γ stimulates the thyroid cell differentiation and inhibits inflammatory processes in this gland

Relation between Environmental Factors and Children’s Health Behaviors Contributing to the Occurrence of Diet-Related Diseases in Central Poland

Proper nutrition is a key element in maintaining normal body weight in children and one of the most important factors influencing their optimum development, growth, and health in the future. The aim of this cross-sectional study was to identify environmental factors which affect health behaviors of children aged 7–14, contributing to the occurrence of diet-related diseases. The study was performed with participation of 892 school children. The investigated environmental factors were as follows: the place of residence, maternal education level, and the level of family income. A questionnaire was used to collect the data from mothers. The study indicated a prevalence of overweight and obesity among children of 13.9% and 1.2%, respectively. Being underweight applied to 20.0% of examined children, more often to girls. In terms of nutritional behaviors an insufficient consumption of vegetables, fruit, whole grain products, dairy products, and fish was observed. The frequency of vegetable and fruit consumption significantly decreased with an increase in child’s body mass index (BMI) (G = −0.110, p < 0.05 and G = −00.114, p < 0.05). Overall, 29.7% of children devoted less than 30 minutes a day to physical activity, besides the physical education classes at school. Boys were more often physically active than girls (G = 0.205, p < 0.0005). There was a positive correlation between frequency of vegetable (G = 0.167, p < 0.0005) and fruit (G = 0.155, p < 0.005) consumption and mothers’ education level. Girls ate fruit more frequently than boys (G = 0.116, p < 0.05). Higher family income was associated with more frequent whole grain consumption (G = 0.095, p < 0.05), while living in the city was negatively correlated with activity (G = −0.121, p < 0.05) and dairy consumption (G = −0.186, p < 0.005). Continuous investigation of environmental factors affecting children eating behaviors may help to bring benefits in increasing the effectiveness of health promotion and educational programs

Impact of the Family Environment on the Frequency of Animal-Based Product Consumption in School-Aged Children in Central Poland

Animal-sourced foods (ASFs) have a high nutritional value, which makes them important elements of young people’s diets. Several environmental factors might affect the dietary habits of children and adolescents, and their identification seems to be a principal reason to maintain their healthy eating practice. Thus, we aimed to investigate selected environmental factors (a place of residence, net income, mother’s education level, number of siblings, and mother’s BMI), which may be linked to the consumption frequency of ASFs among school-aged children. In total, 892 mothers of primary school children aged 7–14 years from central Poland took part in the anonymous and voluntary survey. The frequency of meat and meat product consumption was affected by the mother’s education level, place of residence, and net income. Generally, meat was eaten more often by the city children (G = 0.178, p p p p p boys, G = 0.123, p village, G = 0.214, p city, G = 0.97, p <0.05). It can be concluded that the mother’s level of education is a key factor linked to the selected children’s dietary habits. Thus, we believe that successful health education programs designed for young people should include the maternal capacity to interpret and adapt information into daily practice

Family Factors Associated with Selected Childhood Nutrition Aspects in Central Poland

Childhood diet has a significant influence on diet-related diseases in adulthood, so an understanding of environmental influences on nutrition, is important. The aim of this cross-sectional study was to indicate family factors associated with some aspects of children&#8217;s nutrition in Central Poland. A questionnaire was used to investigate 892 mothers&#8217; approach to breastfeeding, frequency of eating with children at fast food restaurants, and serving them snacks, sugary drinks, and fried food. Prevalence of dental caries among children, based on the mothers&#8217; self-assessment, was also assessed. Majority of the mothers breastfed for a period not longer than six months. There was a positive association between breastfeeding duration and mothers&#8217; education level and the number of children in a family. Sweets were used as a reward, more often among younger children and in families with higher number of children. The frequency of consumption of sweet beverages rose with the child&#8217;s age and decreased with mother&#8217;s education level and family income. It was also more frequent in rural areas. Most children received snacks and fried food at least once a week. There was a negative association between eating with parents at fast food restaurants and, both, the number of children in the family and living in a village. Fast food consumption rose with the mother&#8217;s education level and family income. Prevalence of dental caries according to mothers&#8217; declarations was much lower than in national studies but was associated with frequent consumption of snacks and sweet beverages in the examined population. Extensive activities to reduce the occurrence of dental caries at the national level and education concerning the role of a family environment in providing a proper childhood nutrition, with a special emphasis on breastfeeding benefits, seems necessary for Polish parents. Designing community-wide education campaigns referencing population-based programs and other health and disease prevention activities, need to be promoted

Effects of Dietary Protein on Thyroid Axis Activity

Thyroid hormones (TH) are essential for the normal development and function of every vertebrate. The hypothalamic-pituitary-thyroid (HPT) axis is regulated to maintain euthyroid status. One of the most influential environmental factors that determines HPT axis activity is nutrition. Both food availability and substrate diversity affect thyroid hormone economy. The present paper aims to summarize literature data concerning the influence of the amount and the type of protein on thyroid axis activity. This review sheds light on the contribution of a low-protein diet or insufficient intake of essential amino acids to TH abnormalities. We believe that the knowledge of these dependencies could improve the results of nutritional interventions in thyroid axis disorders and enhance the efficiency of animal breeding

The State of Knowledge about Nutrition Sources of Vitamin D, Its Role in the Human Body, and Necessity of Supplementation among Parents in Central Poland

The percentage of children with vitamin D deficiency in Poland is alarming. The aim of the study was to assess the knowledge about sources of food and the function of vitamin D, as well as the frequency of its supplementation. A survey was conducted among the parents of children from Central Poland attending primary schools, and a questionnaire containing mainly open-ended questions was used to collect the data. Most mothers knew at least one of the functions of vitamin D in the body but had a low level of knowledge about its dietary sources. Only a small group of respondents supplemented themselves and their children with vitamin D. Statistically significant influences on the level of knowledge about the functions and sources of vitamin D were place of residence (i.e., better knowledge in the countryside) and mothers&rsquo; level of education (i.e., the better educated, the greater knowledge). In the case of monthly income level, such impact was observed only in relation to the knowledge of vitamin D functions. Concerning the frequency of supplementation, only maternal level of education had a statistically significant effect (i.e., the higher the education level, the higher the frequency of supplementation). In addition, mothers who were aware of functions of vitamin D and nutritional sources, significantly more frequently supplemented vitamin D