An investigation into the relationship between screen time, consumption of advertised foods, and physical activity among Texas 4th grade elementary school children

Background. The high prevalence of obesity among children has spurred creation of a list of possible causative factors, including the advertising of foods of minimal nutritional value, a decrease in physical activity, and increased media use. Few studies show prevalence rates of these factors among large cohorts of children. ^ Methods. Using data from the 2004-2005 School Physical Activity and Nutrition project (SPAN), a secondary analysis of 7907 4th-grade children (mean age 9.74 years) was conducted. In addition, a comic-book–based intervention that addressed advertised food consumption, physical activity, and media use was developed and evaluated using a pre-post test design among 4th-grade children in an urban school district. ^ Results. Among a cohort of 4th-grade children across the state of Texas, children who had more than 2 hours of video game or computer time the previous day were more than twice as likely to drink soda and eat candy or pastries. In addition, children who watched more than 2 hours of TV the previous day were more than three times as likely to consume chips, punch, soda, candy, frozen desserts, or pastries (AOR 3.41, 95% CI: 1.58, 7.37). A comic-book based intervention held great promise and acceptance among 4th-grade children. Outcome evaluation showed that while results moved in a positive direction, they were not statistically significant. ^ Conclusion. Statistically significant associations were found between screen time and eating various types of advertised food. The comic book intervention was widely accepted by the children exposed to it, and pre-post surveys indicated they moved constructs in a positive direction. Further research is needed to look at more specific ways in which children are exposed to TV, and the relationship of the TV viewing time with their consumption of advertised foods. In addition, researchers should look at comic book interventions more closely and attempt to utilize them in more in studies with a longer follow-up time. ^

Foodborne illness - An age old problem requiring contemporary solutions

Foodborne illness has always been with us, and food safety is an increasingly important public health issue affecting populations worldwide. In the United States of America, foodborne illness strikes millions of people and kills thousands annually, costing our economy billions of dollars in medical care expense and lost productivity. The nature of food and foodborne illness has changed dramatically in the last century. The regulatory systems have evolved to better assure a safe food supply. The food production industry has invested heavily to meet regulatory requirement and to improve the safety of their products. Educational efforts have increased public awareness of safe food handling practices, empowering consumers to fulfill their food safety role. Despite the advances made, none of the Healthy People 2010 targets for reduction of foodborne pathogens has been reached. There is no single solution to eliminating pathogen contamination from all classes of food products. However, irradiation seems especially suited for certain higher-risk foods such as meat and poultry and its use should advance the goal of reducing foodborne illness by minimizing the presence of pathogenic organisms in the food supply. This technology has been studied extensively for over 50 years. The Food and Drug Administration has determined that food irradiation is safe for use as approved by the Agency. It is time to take action to educate consumers about the benefits of food irradiation. Consumer demand will compel industry to meet demand by investing in facilities and processes to assure a consistent supply of irradiated food products. ^

THE RECOVERY OF ENTEROPATHOGENS FROM CONTAMINATED COOKED FOODS AT HOLDING TEMPERATURES

Hot foods served in foodservice establishments, institutions and homes, have always been regarded as safe, since cooking temperatures are more likely to kill the bacterial agents that may cause foodborne diseases. However, foods that are otherwise served hot have been epidemiologically incriminated for causing foodborne diseases. This situation arises due to the possible post-cooking food contamination. Post-cooking contamination of hot-held food is most threatening for it gives the contaminating agents the possibility of proliferation. On one hand, post-cooking contamination is least understood and on the other, hot-holding of food gives the consumer a false sense of freedom from foodborne diseases. In this study, the dynamics of food contamination before or after cooking and during hot-holding are discussed and a food contamination dynamics model is presented.^ The literature on foodborne cholera, cholera-like diarrhea, shigellosis and E. coli gastroenteritis together with the literature on the occurrence and growth of the causative enteropathogens; 01 V. cholerae, non-01 V. cholerae, S. sonnei, S. flexneri and E. coli were reviewed. The literature on the infective doses of these organisms were also cited.^ In the study, four cooked food types held hot at 40-60(DEGREES)C were deliberately contaminated with 01 V. cholerae, non-01 V. cholerae, S. sonnei, S. flexneri and E. coli, one at a time at each of the hot-holding temperatures. Tested food samples for the recovery of these enteropathogens were withdrawn at various time intervals of hot holding.^ The results showed bacterial recovery to decline with increasing temperature and with increasing hot-holding time within each holding temperature. All the bacterial types except V. cholerae were recovered even after holding the food at 60(DEGREES)C for one hour. V. cholerae was not recovered after hot-holding the food at 50-60(DEGREES)C at certain holding periods. After 48 hrs incubation, V. cholerae was recovered on TCBS agar plates that read negative after the initial 24 hrs of incubation. Effective hot-holding temperatures were determined for each of the food types contaminated by each of the bacterial types.^ Statistical analysis of the collected data showed temperature, bacterial type and their interaction to be significant in enteropathogen recovery. Food type and its interactions with temperature and bacterial type were found not significant. ^

Supplemental Nutrition Assistance Program: A policy analysis of restricting foods with minimal nutritional value

In 2011, expenditures for the Supplemental Nutrition Assistance Program (SNAP) reached an all-time high of $72 billion. The goal of SNAP is " to alleviate hunger and malnutrition…by increasing food purchasing power for all eligible households who apply for participation." It has been well established that proper nutrition is essential to good health, making SNAP an important program to public health consumers. Thus, this analysis examined whether SNAP is meeting its stated goal and whether the goal would be reduced if the purchase of foods of minimal nutritional value (FMNV) were restricted. ^ A review of existing literature found that SNAP has been shown to alleviate hunger, but the studies on the nutritional impact of the program were not sufficient to assert whether change is needed. When considering whether limiting FMNV would reduce or improve the effectiveness of SNAP at alleviating hunger and malnutrition, there is very little information on which to base a policy change, particular one that singles out a low income group to restrict purchases. ^ Several states have attempted to restrict the purchase of FMNV but, to date, no such change has been implemented or tested. Conducting pilot studies on the restriction of FMNV, along with better data collection on SNAP purchases, would guide policy changes to the program. Although there are many potential public health benefits to restricting FMNV purchase using SNAP dollars, research is needed to quantify the cost impact of these benefits.^

Student consumption of a la carte foods during school lunch meals

The purpose of this study was to evaluate students' lunch consumption compared to NSLP guidelines, the contribution of competitive foods to calorie intake at lunch, and the differences in nutrient and food group intake between the a la carte food consumers and non- a la carte food consumers.^ In Fall 2011, 1170 elementary and 440 intermediate students were observed anonymously during school lunch. The foods eaten, their source, grade level, and gender were recorded. All a la carte offerings met the Texas School Nutrition Policy.^ Differences in nutrient and food group intake by grade level and between students who consumed a la carte and those who did not were assessed using ANCOVA. A chi-squared analysis was conducted to evaluate differences in a la carte food consumption by grade level, gender, and the school's low income status.^ Average lunch intakes for elementary students were 457 (SD 164) calories for elementary students and 541 calories (SD 188) for intermediate students (p<0.001). 760 students (47%) consumed 937 a la carte foods, with the most often consumed items being chips (32%), ice cream (22%) and snack items (18%). Mean a la carte food intakes were 60 and 98 calories for elementary and intermediate schools respectively (p<0.001). Significantly more (p<0.000) intermediate students (34.3%) consumed a la carte items compared to elementary students (27.5%).^ Students who consumed a la carte foods had significantly higher intakes of calories (p<0.000), fat (p<0.000), sodium (p<0.002), fiber (p<0.000), added sugar (p<0.000), total grains (p<0.000), dessert foods (p<0.000), and snack chips (p<0.000) and lower intakes of vitamin A (p<0.001), iron (p<0.000), fruit (p<0.022), vegetables (p<0.031), milk (p<0.000), and juice (p<0.000) compared to students who did not eat a la carte foods.^ Although previous studies have found that reducing availability of unhealthy items at school decreased student consumption of these items, the results of this study indicate that even the strict guidelines set forth by the state of Texas are not sufficient to prevent increased caloric intake and poor nutrient intake. Strategies to improve student selection and consumption at school lunch when a la carte foods are available are warranted.^

Investigation of the mechanism of increased melanoma incidence in UV -irradiated mouse skin

The availability of transplantable, syngeneic murine melanomas made it possible to study the potential effects of UV radiation on the growth and progression of melanomas in an animal model. The purpose of my study was to determine how UV-irradiation increases the incidence of melanoma out-growth, when syngeneic melanoma cells are transplanted into a UV-irradiated site. Short term intermittent UVB exposure produces a transitory change in the mice which allows the increased outgrowth of melanoma cells injected into the UV-irradiated site. One possible mechanism is an immunomodulatory effect of UVR on the host. An alternative mechanism to account for the increased tumor incidence in the UV-irradiated site, is the release of inflammatory mediators from UV-irradiated epidermal cells. A third possibility is that UVR could induce the production and/or release of melanoma-specific growth factors resulting in increased melanoma outgrowth.^ My first step in distinguishing among these different possible mechanisms was to characterize further the conditions leading to increased development of melanoma cells in UV-irradiated mouse skin. Next, I attempted to determine which of the 3 proposed mechanisms was most likely. To do this, I defined the specificity of the effect by examining the growth of additional C3H tumorigenic cell lines in UV-irradiated skin. Second, I determined the immunogenicity of these tumor cell lines. The tumor cell lines exhibiting increased tumor incidence are restricted to those tumor cell lines which are immunogenic in normal C3H mice. Third, I determined the effect of UVR on melanoma development did not occur in immunosuppressed mice.^ Because of results from these three lines of investigation suggested that the effect was immunologically mediated, I then investigated whether specific immune reactions were affected by local UV irradiation. To accomplish this, I investigated the effect of UVR on cutaneous immune cells and on induction of contact hypersensitivity (CHS), and I also determined the effect of UVR on the development and the expression of systemic immunity against the melanoma cells. There is no clear cut relationship between the number of Langerhans or Thy1+ cells and the UV effect on tumor incidence. Furthermore, there was no suppression of CHS in the UV-irradiated mice. While the development of systemic immunity is significantly reduced, it appears to be sufficient to provide in vivo immunity to tumor challenge. However the elicitation of tumor immunity in immunized mice can be abrogated if tumor challenge occurs in the site of UV irradiation. This investigation provides new information on an effect of UVR on the elicitation of tumor immunity. Furthermore, it indicates that UV radiation can play a role in the development of melanoma other than just in the transformation of melanocytes. ^