Nutritional Supplementation with Essential Amino Acids and Phytosterols May Reduce Risk for Metabolic Syndrome and Cardiovascular Disease in Overweight Individuals with Mild Hyperlipidemia.

BACKGROUND: Hyperlipidemia and insulin resistance are risk factors for the development of metabolic syndrome and cardiovascular disease. We have previously observed that supplementation with essential amino acids (EAA) could lower plasma triglycerides, and may improve glucose metabolism. OBJECTIVE: We sought to determine whether EAA's combined with whey protein and phytosterols would facilitate improvements in plasma lipids and insulin sensitivity in adults with mild hypertriglyceridemia. DESIGN: We enrolled nine subjects who were 50 years or older, had a documented plasma TG >150 mg/dl, and had not recently taken statin medications (within 6 weeks). Each subject served as his or her own control. These individuals underwent an oral glucose tolerance test (OGTT) before and after four weeks consumption of the oral nutritional supplement without dietary counseling or recommendations for physical activity. RESULTS: Plasma total cholesterol and LDL levels decreased in all nine volunteers (P<0.005 for cholesterol and P<0.02 for LDL). In six of these individuals, plasma triglycerides (TG) fell by 95±13 mg/dl (P=0.007); while the other three showed no TG reduction. Genotyping revealed that in two of the three individuals that did not have TG reduction in response to the nutritional supplementation. Insulin sensitivity (ISI) and the total AUCins/glucose were significantly reduced by leucine/EAAs and phytosterol supplementation (P=0.008). CONCLUSIONS: These findings suggest that a dietary supplementation of EAAs and phytosterols may promote favorable reductions of blood lipids as well as insulin resistance in individuals with hypertriglyceridemia. Future larger studies of SNPs and TG response to dietary supplements will be of interest.

Neural coding of phonemic fricative contrast with and without hearing aid.

OBJECTIVE: To determine whether auditory event-related potentials (ERPs) to a phonemic fricative contrast ("s" and "sh") show significant differences in listening conditions with or without a hearing aid and whether the aided condition significantly alters a listener's ERP responses to the fricative speech sounds. DESIGN: The raw EEG data were collected using a 64-channel system from 10 healthy adult subjects with normal hearing. The fricative stimuli were digitally edited versions of naturally produced syllables, /sa/ and /∫a/. The evoked responses were derived in unaided and aided conditions by using an alternating block design with a passive listening task. Peak latencies and amplitudes of the P1-N1-P2 components and the N1' and P2'' peaks of the acoustic change complex (ACC) were analyzed. RESULTS: The evoked N1 and N1' responses to the fricative sounds significantly differed in the unaided condition. The fricative contrast also elicited distinct N1-P2 responses in the aided condition. While the aided condition increased and delayed the N1 and ACC responses, significant differences in the P1-N1-P2 and ACC components were still observed, which would support fricative contrast perception at the cortical level. CONCLUSION: Despite significant alterations in the ERP responses by the aided condition, normal-hearing adult listeners showed distinct neural coding patterns for the voiceless fricative contrast, "s" and "sh," with or without a hearing aid.

Selective listening of concurrent auditory stimuli: an event-related potential study.

This study employed behavioral and electrophysiological measures to examine selective listening of concurrent auditory stimuli. Stimuli consisted of four compound sounds, each created by mixing a pure tone with filtered noise bands at a signal-to-noise ratio of +15 dB. The pure tones and filtered noise bands each contained two levels of pitch. Two separate conditions were created; the background stimuli varied randomly or were held constant. In separate blocks, participants were asked to judge the pitch of tones or the pitch of filtered noise in the compound stimuli. Behavioral data consistently showed lower sensitivity and longer response times for classification of filtered noise when compared with classification of tones. However, differential effects were observed in the peak components of auditory event-related potentials (ERPs). Relative to tone classification, the P1 and N1 amplitudes were enhanced during the more difficult noise classification task in both test conditions, but the peak latencies were shorter for P1 and longer for N1 during noise classification. Moreover, a significant interaction between condition and task was seen for the P2. The results suggest that the essential ERP components for the same compound auditory stimuli are modulated by listeners' focus on specific aspects of information in the stimuli.

The effects of fundamental frequency contour manipulations on speech intelligibility in background noise.

Previous studies have documented that speech with flattened or inverted fundamental frequency (F0) contours is less intelligible than speech with natural variations in F0. The purpose of this present study was to further investigate how F0 manipulations affect speech intelligibility in background noise. Speech recognition in noise was measured for sentences having the following F0 contours: unmodified, flattened at the median, natural but exaggerated, inverted, and sinusoidally frequency modulated at rates of 2.5 and 5.0 Hz, rates shown to make vowels more perceptually salient in background noise. Five talkers produced 180 stimulus sentences, with 30 unique sentences per F0 contour condition. Flattening or exaggerating the F0 contour reduced key word recognition performance by 13% relative to the naturally produced speech. Inverting or sinusoidally frequency modulating the F0 contour reduced performance by 23% relative to typically produced speech. These results support the notion that linguistically incorrect or misleading cues have a greater deleterious effect on speech understanding than linguistically neutral cues.

Coffee and tea consumption and endometrial cancer risk in a population-based study in New Jersey.

We evaluated the role of tea and coffee and substances added (sugar/honey, creamers, and milk) on endometrial cancer risk in a population-based case-control study in six counties in New Jersey, including 417 cases and 395 controls. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were computed using unconditional logistic regression. There was a moderate inverse association with coffee consumption, with an adjusted OR of 0.65 (95% CI: 0.36-1.17) for women who reported more than two cups/day of coffee compared to none. Tea consumption appeared to increase risk (OR: 1.93; 95% CI: 1.08-3.45), but after including the variables sugar/honey and cream/milk added to tea in the model, the risk estimate was attenuated and no longer statistically significant (OR: 1.77; 95% CI: 0.96-3.28 for those consuming more than one cup/day of tea compared to nonusers). There was a suggestion of a decreased risk associated with green tea, but the confidence interval included one (adjusted OR for one or more cups/week vs. none: 0.75; 95% CI: 0.48-1.18). We found an association with adding sugar/honey to tea, with those adding two or more teaspoons/cup having an OR of 2.66 (95% CI: 1.42-4.98; p for trend <0.01) after adjusting for relevant confounders. For sugar/honey added to coffee the corresponding OR was 1.43 (95% CI: 0.81-2.55). Our results indicate that sugars and milk/cream added to coffee and tea should be considered in future studies evaluating coffee and tea and endometrial cancer risk.

The effects of nutritional supplementation throughout an endurance run on leucine kinetics during recovery.

This study determined the effect of nutritional supplementation throughout endurance exercise on whole-body leucine kinetics (leucine rate of appearance [Ra], oxidation [Ox], and nonoxidative leucine disposal [NOLD]) during recovery. Five trained men underwent a 2-h run at 65% VO(2max), during which a carbohydrate (CHO), mixed protein-carbohydrate (milk), or placebo (PLA) drink was consumed. Leucine kinetics were assessed during recovery using a primed, continuous infusion of 1-13C leucine. Leucine Ra and NOLD were lower for milk than for PLA. Ox was higher after milk-supplemented exercise than after CHO or PLA. Although consuming milk during the run affected whole-body leucine kinetics, the benefits of such a practice for athletes remain unclear. Additional studies are needed to determine whether protein supplementation during exercise can optimize protein utilization during recovery.

Reduction of the UV burden to indoor tanners through new exposure schedules: a pilot study.

BACKGROUND: The development of new pigmentation (tan) in human skin after UV exposure requires several days. Once it is developed, the tan can last for weeks. Current recommendations for tanning exposure schedules in the USA (FDA Letter to Manufacturers: Policy on maximum timer interval and exposure schedule for sunlamps, August 21, 1986) allow exposures three times per week for the development of a tan, and one to two times per week for maintenance exposures. However, this policy is often interpreted in the indoor tanning industry as allowing three exposures per week on a continuous basis. We believe that the reduction of the recommended cumulative dose to indoor tanners should be explored. Two approaches for achieving this are (1) decreasing the number of exposures and (2) increasing the time interval between exposures. To explore such changes, we conducted a pilot study. METHODS: The pilot study involved three exposure schedules (evaluated on each of six subjects) that evolved throughout the course of the study. Digital photography, visual assessment and diffuse reflectance spectrometry were used to assess skin color changes. The six pilot subjects were studied for 8-18 weeks. The changes in skin color obtained through the use of the different exposure schedules were compared with changes reported by Caswell (Caswell M, The kinetics of the tanning response to tanning bed exposures, Photodermatol Photoimmunol Photomed 2000: 16: 10-14) who used schedules based on current recommendations. RESULTS: Two out of the three experimental schedules produced tans comparable with those reported by Caswell. In these two schedules, cumulative doses were a factor of 2-3 below doses from current schedules. CONCLUSION: The UV burden to indoor tanners can be substantially reduced without compromising the cosmetic effect. These results need to be confirmed in a larger study.

Metabolic response to provision of mixed protein-carbohydrate supplementation during endurance exercise.

The interaction of substrates and hormones in response to ingestion of intact proteins during endurance exercise is unknown. This study characterized substrate and hormone responses to supplementation during endurance exercise. Nine male runners participated in 3 trials in which a non-fat (MILK), carbohydrate (CHO), or placebo (PLA) drink was consumed during a 2-hour treadmill run at 65% VO2max. Circulating levels of insulin, glucagon, epinephrine, norepinephrine, growth hormone, testosterone, and cortisol were measured. Plasma substrates included glucose, lactate, free fatty acids, and select amino acids. Except for insulin and cortisol, hormones increased with exercise. While post-exercise insulin concentrations declined similarly in all 3 trials, the glucagon increase was greatest following MILK consumption. CHO blunted the post-exercise increase in growth hormone compared to levels in MILK. Free fatty acids and plasma amino acids also were responsive to nutritional supplementation with both CHO and MILK attenuating the rise in free fatty acids compared to the increase observed in PLA. Correspondingly, respiratory exchange ratio increased during CHO. Essential amino acids increased significantly only after MILK and were either unchanged or decreased in CHO. PLA was characterized by a decrease in branched-chain amino acid concentrations. Modest nutritional supplementation in this study altered the endocrine response as well as substrate availability and utilization following and during an endurance run, respectively.