Impacts on Sirtuin Function and Bioavailability of the Dietary Bioactive Compound Dihydrocoumarin.

The plant secondary metabolite and common food additive dihydrocoumarin (DHC) is an inhibitor of the Sirtuin family of NAD+-dependent deacetylases. Sirtuins are key regulators of epigenetic processes that maintain silent chromatin in yeast and have been linked to gene expression, metabolism, apoptosis, tumorogenesis and age-related processes in multiple organisms, including humans. Here we report that exposure to the polyphenol DHC led to defects in several Sirtuin-regulated processes in budding yeast including the establishment and maintenance of Sir2p-dependent silencing by causing disassembly of silent chromatin, Hst1p-dependent repression of meiotic-specific genes during the mitotic cell cycle. As both transient and prolonged exposure to environmental and dietary factors have the potential to lead to heritable alterations in epigenetic states and to modulate additional Sirtuin-dependent phenotypes, we examined the bioavailability and digestive stability of DHC using an in vivo rat model and in vitro digestive simulator. Our analyses revealed that DHC was unstable during digestion and could be converted to melilotic acid (MA), which also caused epigenetic defects, albeit less efficiently. Upon ingestion, DHC was observed primarily in intestinal tissues, but did not accumulate over time and was readily cleared from the animals. MA displayed a wider tissue distribution and, in contrast to DHC, was also detected in the blood plasma, interstitial fluid, and urine, implying that the conversion of DHC to the less bioactive compound, MA, occurred efficiently in vivo.

Timing of serving dessert but not portion size affects young children's intake at lunchtime.

The purpose of this repeated exposure, randomized, cross-over quasi-experimental study was to determine the individual and combined impact of (a) the timing of serving dessert and (b) portion size of main course in 2-5 year old children (n=23) on energy intake at lunch in a childcare setting. Children were served two study lunches (fish or pasta, each with dessert) twice a week for 12 weeks that differed in the timing of dessert (served with or after the main course) and portion size of the main course (reference portion or 50% larger portion). Analyses of variance revealed that serving dessert after the meal resulted in higher energy intakes from both the main course and from dessert, and therefore greater total intake at the meal. Portion size of the main course did not influence total energy intake at the meal. Results indicate that the timing of serving dessert affects children's energy intake regardless of the portion size of the main course. Specifically, serving dessert with the meal reduces total energy intake regardless of the main course portion size. This suggests that offering dessert with the main course may be an effective strategy for decreasing total energy intake at meals in preschool-aged children.

Shape of snack foods does not predict snack intake in a sample of preschoolers: a cross-over study.

BACKGROUND: In the past decade, the proportion snacking has increased. Snack foods consumed are predominantly not nutritious foods. One potential venue to increase children's diet quality is to offer healthy snack foods and we explored if shaped snack foods would lead to increased consumption. METHODS: We investigated the consumption of high-fiber snacks (banana bread, pancakes, and sandwiches) served either in normal (round, square) or shaped (heart, hands, animals) form to preschoolers 2-5 years old attending a local child care center (n = 21). The 9 weeks long, prospective, cross-over intervention study was designed to expose each child repeatedly to each snack in each shape (4 times per snack). Snacks were served as morning or afternoon snack and caretakers' reports were used to account for the child's consumption of a meal preceding the study snack (breakfast or lunch). RESULTS: There was no significant difference in snack consumption between the shaped and normal snacks. However, the mean energy intake from snacks was significantly greater for Caucasian children compared with Asian children. Further, Asian children consumed much less banana bread than the other two snacks. Overall, children who had not eaten breakfast or lunch prior to the morning or afternoon snack ate significantly more calories from the snacks (84.1 kcal, p-value < 0.0001). CONCLUSION: Findings of this study confirm previous research that the shape of the foods does not affect snack consumption in children. However, we also report two unexpected findings: a) the strong interaction between ethnicity and snack consumption and b) that Asian children consumed much less banana bread than Caucasian children. The role of children's ethnic background profoundly affects snack preference and must be considered in the study of children's eating behaviors and in interventions to promote healthy eating habits.

Genistein and genistein-containing dietary supplements accelerate the early stages of cataractogenesis in the male ICR/f rat.

Cataract-related loss of vision affects large numbers of people in today's aging populations and presents a healthcare burden to many nations. The role of dietary supplements within the lens is largely unknown, although benefits from dietary anti-oxidants are expected. In this study, the effects of genistein as its aglycone, a genistein-containing dietary supplement (Novasoy(®)200), and a genistein-containing food (soy protein isolate, PRO-FAM 932) on the development of lens opacity were examined in the hereditary cataractous ICR/f rat. These studies were carried out in a background diet of semi-purified, isoflavone-free AIN-76A with casein as its protein source. The amount of genistein for the experimental diets was standardized to its concentration (as genistein aglycone as well as simple and complex ß-glucoside conjugates) in the soy protein isolate supplement. Also tested was a high-dose genistein diet containing an 11-fold higher amount of genistein aglycone. The composition of each diet was verified by reverse-phase HPLC and blood plasma isoflavone concentrations were determined by LC-tandem mass spectrometry. The development of opacity in each lens was monitored and digitally recorded using slit-lamp examination over the course of the study. Each of the genistein-containing diets caused a significantly more rapid development of fibrous opacification in the anterior cortical region and development of apparent water clefts or vacuoles in the posterior subcapsular region than the AIN-76A control diet; however, the establishment of dense lens opacification was not significantly different between each of the diets. There was also no significant difference observed between the low-dose and high-dose genistein aglycone groups. These data suggest that genistein-containing dietary supplements accelerate the early stages of cataractogenesis in the male ICR/f rat, with no dose-dependent effects.