Human Nutrition Faculty Research and Publications

Weight control and cancer preventive mechanisms: role of IGF-1-mediated signaling pathways

2013-05-02T20:49:40Z

Weight control and cancer preventive mechanisms: role of IGF-1-mediated signaling pathways Xie, Linglin; Wang, Weiqun Overweight and obese not only increase the risk of cardiovascular disease and type-2 diabetes mellitus, but are also now known risk factors for a variety of cancers . Weight control, via dietary calorie restriction (DCR) and/or exercise, has been demonstrated to be beneficial for cancer prevention in various experimental models, but the underlying mechanisms are still not well defined. Recent studies conducted in a mouse skin carcinogenesis model show that weight loss induced a significant reduction of the circulating levels of IGF-1 and other hormones, including insulin and leptin, resulting in reduced IGF-1-dependent signaling pathways, i.e., Ras-MAP-proliferation and Akt-PI3K-antiapoptosis. Selective targeting IGF-1 to Akt/mTOR and AMPK pathways, via negative energy balance, might inactivate cell cycle progression and ultimately suppress tumor development. This review highlights the current studies focused on the major role of reducing IGF-1-activated signaling via weight control as a potential cancer preventive mechanism.

Factors influencing the implementation of organized physical activity and fruit and vegetable snacks in the HOP’N After-School Obesity Prevention Program

2013-04-03T16:01:55Z

Factors influencing the implementation of organized physical activity and fruit and vegetable snacks in the HOP’N After-School Obesity Prevention Program Hastmann, Tanis J.; Bopp, Melissa; Fallon, Elizabeth A.; Rosenkranz, Richard R.; Dzewaltowski, David A. Objective: To identify barriers and facilitators for improving the after-school organized physical activity (PA) and snack quality. Methods: After-school staff (Year 1, n = 20; Year 2, n = 17) participated in qualitative, semistructured interviews about the implementation of an after-school obesity prevention intervention. Interviews were recorded, transcribed, coded for common themes, and analyzed using NVivo software. Results: Several factors influencing implementation of PA and fruit and vegetable (FV) consumption were revealed. Facilitators for PA included: staff training, equipment/gym space, and scheduling organized PA. Physical activity barriers included prioritizing PA and lack of school administration support. Fruit and vegetable facilitators included requesting healthier snacks. Fruit and vegetable barriers included cost and low priority of snack. Conclusions and Implications: The success of improving after-school PA and FV snack quality is dependent on many factors, including several organizational system and staff variables. Future research should focus on systemic changes in the after-school environment to increase the priority of daily PA and a healthy snack.

Volatile compounds in dry dog foods and their influence on sensory aromatic profile

2013-03-21T13:54:01Z

Volatile compounds in dry dog foods and their influence on sensory aromatic profile Koppel, Kadri; Adhikari, Koushik; Di Donfrancesco, Brizio The aim of this study was to determine volatile compounds in dry dog foods and their possible influence on sensory aromatic profile. Grain-free dry dog foods were compared to dry dog foods manufactured with grain, but also with different protein sources for their aromatic volatiles. Solid-phase microextraction/gas chromatography/mass spectrometry was used to determine the aromatic compounds present in the headspace of these samples. Partial Least Squares regression was performed to correlate the instrumental aromatic data with the descriptive aroma analysis data. A total of 54 aromatic compounds were tentatively identified in the dry dog food samples, with aldehydes and ketones being the most represented organic volatiles group. Grain-added products were on the average higher in total volatiles than grain-free products. Partial Least Squares regression analysis indicated possible connections with sensory aromatic profile and grain-added samples, such as rancid aroma and aldehydes, especially hexanal. The results of this study showed that dry dog foods are products with complex odor characteristics and that grain-free products are less aromatic.

Chronic disease and sitting time in middle-aged Australian males: findings from the 45 and Up Study

2013-03-21T13:27:09Z

Chronic disease and sitting time in middle-aged Australian males: findings from the 45 and Up Study George, Emma S.; Rosenkranz, Richard R.; Kolt, Gregory S. Background: Compared to females, males experience a range of health inequities including higher rates of diabetes and cardiovascular disease. Although sitting time is emerging as a distinct risk factor for chronic disease, research on the association of sitting time and chronic disease in middle-aged Australian males is limited. Methods: A sample of 63,048 males aged 45-64 years was drawn from the baseline dataset of the 45 and Up Study – a longitudinal cohort study on healthy ageing with 267,153 participants from across New South Wales, Australia’s most populous state. Baseline data on self-reported chronic disease (heart disease, cancer, diabetes, high blood pressure, combined chronic diseases), sitting time, physical activity (Active Australia Survey), and a range of covariates were used for cross-sectional analyses. Crude (OR), partially and fully adjusted odds ratios (AOR) and 95% confidence intervals (CI) were calculated using binary logistic regression. Results: Compared to those sitting <4 hours/day, participants reporting 4 to <6, 6 to <8, and ≥8 hours were significantly more likely to report ever having any chronic disease (AOR 1.06, 95% CI 1.00 – 1.12, p = 0.050; AOR 1.10, 95% CI 1.03 – 1.16, p = 0.003; AOR 1.09, 95% CI 1.03 – 1.15, p = 0.002, respectively). Participants who reported 6 to <8 hours and ≥8 hours of sitting were also significantly more likely to report ever having diabetes than those reporting <4 hours/day (AOR 1.15, 95% CI 1.03 – 1.28, p = 0.016; AOR 1.21, 95% CI 1.09 – 1.33, p <0.001, respectively). Conclusions: Our findings suggest that higher volumes of sitting time are significantly associated with diabetes and overall chronic disease, independent of physical activity and other potentially confounding factors. Prospective studies using valid and reliable measures into domain-specific sitting time in middle-aged males are required to understand and explain the direction of these relationships.