Publications by authors named "Dawna Salter Venzon"

The release characteristics of a unique blend of carotenoid beadlets designed to increase bioavailability were tested using the dynamic gastrointestinal model TIM-1. Individual carotenoid bioaccessibility peaks were observed over approximately 3-4 hr in the order of lutein and zeaxanthin first, followed by lycopene, and then finally α- and β-carotene; when tested as a beadlet blend or when the beadlets were compressed into tablets. Bioaccessibility measurements of 7%-20% were similar to those previously reported in literature and comparable between the two formulations, beadlet blend and tablet formulations.

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Carotenoids, a class of phytonutrients, have been well established to boost skin's innate resistance against ultraviolet (UV) B-induced erythema (sunburn). Many of the published clinical studies thus far have focused on the measurement of erythema as the primary clinical indicator of skin protection against UVB radiation. More recent studies have shown that carotenoid supplementation provides even more skin protection than previously shown as new clinical and molecular endpoints beyond UVB-induced erythema have been reported.

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Despite the notable health benefits of carotenoids for human health, the majority of human diets worldwide are repeatedly shown to be inadequate in intake of carotenoid-rich fruits and vegetables, according to current health recommendations. To address this deficit, strategies designed to increase dietary intakes and subsequent plasma levels of carotenoids are warranted. When mixed carotenoids are delivered into the intestinal tract simultaneously, competition occurs for micelle formation and absorption, affecting carotenoid bioavailability.

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Since the 1980's when the predominate focus of study and use of carotenoids in human nutritional formulations was solely on beta-carotene, there has been a steady increase in research aimed to understand the role of a wide variety of carotenoids in human health. This work has increasingly demonstrated the benefits of a number of carotenoids, and there has been a corresponding increase in the number of carotenoids provided in nutritional supplements (multicarotenoids). Numerous published observations in both human and animal studies suggest significant interaction and competition between various carotenoids during absorption and metabolism, resulting in the inhibition of uptake of one over the other.

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Anorexia that accompanies cellular dehydration in rats (DE-anorexia) offers a relatively simple model for investigating the functional organization of neural mechanisms that can suppress feeding during dehydration. Previous studies strongly suggest that the inputs that drive ingestive behavior control neurons in the paraventricular nucleus of the hypothalamus (PVH) and lateral hypothalamic area (LHA) remain active during DE-anorexia. Here we examine whether these two regions retain their sensitivity to neuropeptide Y (NPY).

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Acute effects of high-sugar/low-fiber meals vs low-sugar/high-fiber meals on hormones and behavior were studied in 10 overweight Latina females, age 11 to 12 years, using a crossover design. In this exploratory pilot study, participants arrived fasted at an observation laboratory on two occasions and randomly received either a high-sugar/low-fiber meal or a low-sugar/high-fiber meal at each visit. Glucose, insulin, and leptin were assayed from serum drawn at 0, 15, 30, 60, 90, and 120 minutes.

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Giving rats 2.5% saline to drink for 3-5 days simply and reliably generates anorexia. Despite having the neurochemical and hormonal markers of negative energy balance, dehydrated anorexic rats show a marked suppression of spontaneous food intake, as well as the feeding that is usually stimulated by overnight starvation or a 2-deoxy-d-glucose (2DG) challenge.

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