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Background: Although dietary flavonoid intake has been associated with less weight gain, there are limited data on its impact on fat mass, and to our knowledge, the contribution of genetic factors to this relation has not previously been assessed. Objective: We examined the associations between flavonoid intakes and fat mass. Design: In a study of 2734 healthy, female twins aged 18-83 y from the TwinsUK registry, intakes of total flavonoids and 7 subclasses (flavanones, anthocyanins, flavan-3-ols, flavonols, flavones, polymers, and proanthocyanidins) were calculated with the use of food-frequency questionnaires. Measures of dual-energy X-ray absorptiometry-derived fat mass included the limb-to-trunk fat mass ratio (FMR), fat mass index, and central fat mass index. Results: In cross-sectional multivariable analyses, higher intake of anthocyanins, flavonols, and proanthocyanidins were associated with a lower FMR with mean ± SE differences between extreme quintiles of 20.036 0.02 (P-trend = 0.02),20.03 ± 0.02 (P-trend = 0.03), and 20.05 ± 0.02 (P-trend < 0.01), respectively. These associations were not markedly changed after further adjustment for fiber and total fruit and vegetable intakes. In monozygotic, intakediscordant twin pairs, twins with higher intakes of flavan-3-ols (n = 154, P = 0.03), flavonols (n = 173, P = 0.03), and proanthocyanidins (n = 172, P < 0.01) had a significantly lower FMR than that of their co-twins with within-pair differences of 3-4%. Furthermore, in confirmatory food-based analyses, twins with higher intakes of flavonolrich foods (onions, tea, and pears; P = 0.01) and proanthocyanidin-rich foods (apples and cocoa drinks; P = 0.04) and, in younger participants (aged <50 y) only, of anthocyanin-rich foods (berries, pears, grapes, and wine; P = 0.01) had a 3-9% lower FMR than that of their co-twins. Conclusions: These data suggest that higher habitual intake of a number of flavonoids, including anthocyanins, flavan-3-ols, flavonols, and proanthocyanidins, are associated with lower fat mass independent of shared genetic and common environmental factors. Intervention trials are needed to further examine the effect of flavonoid-rich foods on body composition. [ABSTRACT FROM AUTHOR]

Background: Passive overconsumption is the increase in energy intake driven by the high-fat energy-dense food environment. This can be explained in part because dietary fat has a weaker effect on satiation (i.e. process that terminates feeding). Habitually active individuals show improved satiety (i.e. process involved in post-meal suppression of hunger) but any improvement in satiation is unknown. Here we examined whether habitual physical activity mitigates passive overconsumption through enhanced satiation in response to a high-fat meal. Methods: Twenty-one non-obese individuals with high levels of physical activity (HiPA) and 19 individuals with low levels of physical activity (LoPA) matched for body mass index (mean = 22.8 kg/m²) were recruited. Passive overconsumption was assessed by comparing ad libitum energy intake from covertly manipulated high-fat (HFAT; 50% fat) or high-carbohydrate (HCHO; 70% carbohydrate) meals in a randomized crossover design. Habitual physical activity was assessed using SenseWear accelerometers (SWA). Body composition, resting metabolic rate, eating behaviour traits, fasting appetite-related peptides and hedonic food reward were also measured. Results: In the whole sample, passive overconsumption was observed with greater energy intake at HFAT compared to HCHO (p < 0.01), without any differences between activity groups (p > 0.05). SWA confirmed that HiPA were more active than LoPA (p < 0.01). HiPA had lower body fat and greater fat-free mass than LoPA (p < 0.05 for both) but did not differ in resting metabolic rate, eating behaviour traits, appetite-related peptides or food reward (p > 0.05 for all). Conclusions: Non-obese individuals with high or low physical activity levels but matched for BMI showed similar susceptibility to passive overconsumption when consuming an ad libitum high-fat compared to a high-carbohydrate meal. This occurred despite increased total daily energy expenditure and improved body composition in HiPA. Greater differences in body composition and/or physical activity levels may be required to impact on satiation. [ABSTRACT FROM AUTHOR]

Background: Obesity is increasing in parallel with greater all-day food availability. The latter may promote meal irregularity, dysregulation of the energy balance, and poor metabolic health. Objective: We investigated the effect of meal irregularity on the thermic effect of food (TEF), lipid concentrations, carbohydrate metabolism, subjective appetite, and gut hormones in healthy women. Design: Eleven normal-weight women (18-40 y of age) were recruited in a randomized crossover trial with two 14-d isoenergetic diet periods (identical foods provided and free living) that were separated by a 14-d habitual diet washout period. In period 1, participants followed a regular meal pattern (6 meals/d) or an irregular meal pattern (3-9 meals/d), and in period 2, the alternative meal pattern was followed. Before and after each period, when participants were fasting and for 3 h after intake of a test drink, measurements were taken of energy expenditure, circulating glucose, lipids (fasting only), insulin, glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and ghrelin. An ad libitum test meal was offered. Subjective appetite ratings were assessed while fasting, after the test drink, after the ad libitum meal, and during the intervention. Continuous interstitial glucose monitoring was undertaken for 3 consecutive days during each intervention, and the ambulatory activity pattern was recorded (ambulatory energy expenditure estimation). Results: Regularity was associated with a greater TEF (P, 0.05) and a lower incremental area under the curve (iAUC) for glucose after intake of the test drink (over 3 h) and, for some identical meals, during the 2 interventions (over 90 min) (day 7: after breakfast; day 9: after lunch and dinner). There was no difference between treatments for the test-drink gut hormone response. A time effect was noted for fasting GLP-1, fasting PYY, PYY responses, and hunger-rating responses to the test drink (P < 0.05). Lower hunger and higher fullness ratings were seen premeal and post-meal during the regular period while subjects were free living. Conclusion: Meal regularity appears to be associated with greater TEF and lower glucose responses, which may favor weight management and metabolic health. This trial was registered at clinical-trials.gov as NCT02052076. [ABSTRACT FROM AUTHOR]

Background: Poorly absorbed fermentable carbohydrates can provoke irritable bowel syndrome (IBS) symptoms by escaping absorption in the small bowel and being rapidly fermented in the colon in some susceptible subjects. IBS patients often are anxious and stressed, and stress accelerates small bowel transit, which may exacerbate malabsorption. Objective: In this study we investigated the effect of an intravenous injection of corticotropin-releasing factor (CRF) on fructose malabsorption and the resulting volume of water in the small bowel. Design: We performed a randomized, placebo-controlled crossover study of CRF compared with saline injection in 11 male and 10 female healthy subjects, examining the effect on the malabsorption of a 40-g fructose test meal and its transit through the gut, which was assessed by serial MRI and breath hydrogen measurement. Orocecal transit was assessed with the use of the lactose [13C]ureide breath test and the adrenal response to CRF was assessed by serial salivary cortisol measurements. Results: CRF injection caused a significant increase in salivary cortisol, which lasted for 135 min. Small bowel water content (SBWC) rose from baseline, peaking at 45 min after fructose ingestion, whereas breath hydrogen peaked later, at 75 min. The area under the curve for SBWC from –15 min to 135 min was significantly lower after CRF compared with saline [mean difference: 5911 mL · min (95% CI: 18.4, 11,803 mL · min), P = 0.049]. Considering all subjects, the percentage change in ascending colon volume rose significantly after CRF. This increase was significant for male (P = 0.026), but not female, volunteers. Conclusions: CRF constricts the small bowel and increases fructose malabsorption, as shown by increased ascending colon volumes. This mechanism may help to explain the increased sensitivity of some stressed individuals to fructose malabsorption. This trial was registered at clinicaltrials.gov as NCT01763281. [ABSTRACT FROM AUTHOR]

Background: The causal nature of associations between breakfast and health remain unclear in obese individuals. Objective: We sought to conduct a randomized controlled trial to examine causal links between breakfast habits and components of energy balance in free-living obese humans. Design: The Bath Breakfast Project is a randomized controlled trial with repeated measures at baseline and follow-up among a cohort in South West England aged 21-60 y with dual-energy X-ray absorpti-ometry-derived fat mass indexes of ≥13 kg/m² for women (n = 15) and ≥9 kg/m² for men (n = 8). Components of energy balance (resting metabolic rate, physical activity thermogenesis, diet-induced thermo-genesis, and energy intake) were measured under free-living conditions with random allocation to daily breakfast (≥700 kcal before 1100) or extended fasting (0 kcal until 1200) for 6 wk, with baseline and follow-up measures of health markers (e.g., hematology/adipose biopsies). Results: Breakfast resulted in greater physical activity thermogenesis during the morning than when fasting during that period (difference: 188 kcal/d; 95% CI: 40, 335) but without any consistent effect on 24-h physical activity thermogenesis (difference: 272 kcal/d; 95% CI: -254, 798). Energy intake was not significantly greater with breakfast than fasting (difference: 338 kcal/d; 95% CI: 2313, 988). Body mass increased across both groups over time but with no treatment effects on body composition or any change in resting metabolic rate (stable within 8 kcal/d). Metabolic/cardiovascular health also did not respond to treatments, except for a reduced insulinemic response to an oral-glucose-tolerance test over time with daily breakfast relative to an increase with daily fasting (P = 0.05). Conclusions: In obese adults, daily breakfast leads to greater physical activity during the morning, whereas morning fasting results in partial dietary compensation (i.e., greater energy intake) later in the day. There were no differences between groups in weight change and most health outcomes, but insulin sensitivity increased with breakfast relative to fasting. This trial was registered at www.isrctn.org as ISRCTN31521726. [ABSTRACT FROM AUTHOR]

Background: The beneficial cardiovascular effects of vegetables may be underpinned by their high inorganic nitrate content. Objective: We sought to examine the effects of a 6-wk once-daily intake of dietary nitrate (nitrate-rich beetroot juice) compared with placebo intake (nitrate-depleted beetroot juice) on vascular and platelet function in untreated hypercholesterolemics. Design: A total of 69 subjects were recruited in this randomized, double-blind, placebo-controlled parallel study. The primary endpoint was the change in vascular function determined with the use of ultrasound flow-mediated dilatation (FMD). Results: Baseline characteristics were similar between the groups, with primary outcome data available for 67 patients. Dietary nitrate resulted in an absolute increase in the FMD response of 1.1% (an ~24% improvement from baseline) with a worsening of 0.3% in the placebo group (P < 0.001). A small improvement in the aortic pulse wave velocity (i.e., a decrease of 0.22 m/s; 95% CI: -0.4, -0.3 m/s) was evident in the nitrate group, showing a trend (P = 0.06) to improvement in comparison with the placebo group. Dietary nitrate also caused a small but significant reduction (7.6%) in platelet-monocyte aggregates compared with an increase of 10.1% in the placebo group (P = 0.004), with statistically significant reductions in stimulated (ex vivo) P-selectin expression compared with the placebo group (P < 0.05) but no significant changes in unstimulated expression. No adverse effects of dietary nitrate were detected. The composition of the salivary microbiome was altered after the nitrate treatment but not after the placebo treatment (P < 0.01). The proportions of 78 bacterial taxa were different after the nitrate treatment; of those taxa present, 2 taxa were responsible for >1% of this change, with the proportions of Rothia mucilaginosa trending to increase and Neisseria flavescens (P < 0.01) increased after nitrate treatment relative to after placebo treatment. Conclusions: Sustained dietary nitrate ingestion improves vascular function in hypercholesterolemic patients. These changes are associated with alterations in the oral microbiome and, in particular, nitrate-reducing genera. Our findings provide additional support for the assessment of the potential of dietary nitrate as a preventative strategy against atherogenesis in larger cohorts. This trial was registered at clinicaltrials.gov as NCT01493752. [ABSTRACT FROM AUTHOR]

Background: Personal and family data forms, completed by women referred to breast cancer genetics clinics, are valuable tools for verification and extension of family history, crucial steps in accurate risk evaluation. A significant minority of women do not complete and return these forms, despite reminders, even when completion is a pre‐requisite for a clinic appointment. Objective: To facilitate access of women at increased familial risk of breast cancer to screening and counselling services by investigating reasons for non‐return of the forms. Participants and Design: Based on a single regional ‘breast cancer family’ service in the UK, Analysis of quantitative data comparing women who did not return forms (n = 55) with those who had done so (n = 59), together with qualitative evaluation of potential barriers to form‐completion through semi‐structured telephone interviews with a random subset of ‘non‐returners’ (n = 23). Results: Non‐returners have higher proportions of the very young (below the age at which surveillance could be offered) and of women from lower social deprivation categories. Interviews revealed that the majority of non‐returners are anxious, rather than unconcerned about their breast cancer risk and circumstances and attitudes contributed to non‐compliance. Twenty‐one participants confirmed that they would welcome an appointment at a ‘breast cancer family’ clinic, but nine did not attend for the appointment. They were significantly younger than those who attend, but were not at lower familial risk. Discussion and Conclusions: Many women who fail to complete and return a family history form would benefit from risk assessment and genetic counselling. Several steps are suggested that might help them access the relevant services. [ABSTRACT FROM AUTHOR]

Background: Increased brain atrophy rates are common in older people with cognitive impairment, particularly in those who eventually convert to Alzheimer disease. Plasma concentrations of omega-3 (ω-3) fatty acids and homocysteine are associated with the development of brain atrophy and dementia. Objective: We investigated whether plasma ω-3 fatty acid concentrations (eicosapentaenoic acid and docosahexaenoic acid) modify the treatment effect of homocysteine-lowering B vitamins on brain atrophy rates in a placebo-controlled trial (VITACOG). Design: This retrospective analysis included 168 elderly people (≥70 y) with mild cognitive impairment, randomly assigned either to placebo (n = 83) or to daily high-dose B vitamin supplementation (folic acid, 0.8 mg; vitamin B-6, 20 mg; vitamin B-12, 0.5 mg) (n = 85). The subjects underwent cranial magnetic resonance imaging scans at baseline and 2 y later. The effect of the intervention was analyzed according to tertiles of baseline ω-3 fatty acid concentrations. Results: There was a significant interaction (P = 0.024) between B vitamin treatment and plasma combined ω-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) on brain atrophy rates. In subjects with high baseline ω-3 fatty acids (>590 µmol/L), B vitamin treatment slowed the mean atrophy rate by 40.0% compared with placebo (P = 0.023). B vitamin treatment had no significant effect on the rate of atrophy among subjects with low baseline ω-3 fatty acids (<390 µmol/L). High baseline ω-3 fatty acids were associated with a slower rate of brain atrophy in the B vitamin group but not in the placebo group. Conclusions: The beneficial effect of B vitamin treatment on brain atrophy was observed only in subjects with high plasma ω-3 fatty acids. It is also suggested that the beneficial effect of ω-3 fatty acids on brain atrophy may be confined to subjects with good B vitamin status. The results highlight the importance of identifying subgroups likely to benefit in clinical trials. This trial was registered at www.controlled-trials.com as ISRCTN94410159. [ABSTRACT FROM AUTHOR]

Quantitative analyses of the macronutrient content of eight popular commercial 'ready-to-feed' baby meals for 6-9-month old infants in the UK market have been undertaken in order to ascertain their nutritional suitability in relation to the total daily dietary intake as well as nutritional profiling of the products. The chemical analyses conducted included Kjeldhal for protein, acid hydrolysis and extraction for fat, phenol sulphuric acid for carbohydrate and Association of Official Analytical Chemists 985.29 for fibre. The only difference found between different varieties (meat- and vegetable-based) was with respect to the protein content ( P = 0.04) per 100 g of food. The experimentally determined concentrations of macronutrients (g/100 kcal) were compared with the declared values provided by the manufacturers on the product labels and, despite some variations, the values obtained comply with regulatory requirements ( Commission Directive 2006/125/ EC). The total daily intake of fat (27.0 g per day) - based on the menu composed from commercial complementary food - is suggested to exceed the daily recommended values for fat (31%), if the intake of snacks and desserts are incorporated. These findings imply that the formulation of recipes, based on a standard commercial menu, is an important consideration in relation to the nutritional quality of the diet of infants. [ABSTRACT FROM AUTHOR]

BACKGROUND: 123I-FP-CIT (DaTSCAN) SPECT studies of the nigrostriatal pathway are a valuable tool in the diagnosis of movement disorders. However some scans are reported as equivocal with potential adverse consequences. We investigated whether the use of quantification of tracer uptake within the striatum can be used to reduce the number of equivocal reports. MATERIAL AND METHODS: BRASS software (Hermes, Sweden) was used to quantify striatal tracer uptake in DaTSCAN stud- ies of patients referred to our institution. Scans were quantified and numerical limits were determined to distinguish between normal and abnormal scans. Scans were then re-reported both with, and without, the use of quantification. Number of equivocal reports and accuracy of reporting between the two types of reporting were compared. RESULTS: Scan reporting using quantification led to a significant reduction in the number of equivocal reports with no significant change in reporting accuracy. CONCLUSION: Automated quantification of DaTSCAN studies with BRASS and the use of numerical limits can decrease the number of equivocal reports without affecting report accuracy. [ABSTRACT FROM AUTHOR]

Background: The manipulation of the composition of foods consumed as between-meal snacks may aid daily energy restriction. Objectives: We compared the effects of the consumption of 2 energy-matched snack bars on appetite, energy intake (EI), and metabolic and endocrine responses. In addition, we investigated whether the acute effects of the consumption of snacks were maintained under free-living conditions and whether the habitual daily consumption of the snack over 14 d influenced these effects. Design: Ten lean men [mean ± SD age: 30.7 ± 9.7 y; body mass index (in kg/m²): 23.2 ± 2.8] consumed a whey protein and polydextrose (PPX) snack bar or an isoenergetic control snack bar as a midmorning, between-meal snack for 14 consecutive days in a double-blind, randomized, crossover design. The two 14-d intervention phases were separated by a 14-d washout period. On the first (day 1) and last (day 15) days of each intervention phase, appetite, food intake, and blood metabolite and endocrine responses were assessed under laboratory conditions. Free-living EI was recorded on days 4, 8, and 12 of interventions. Results: Total daily EI was significantly lower when the PPX snack was consumed during experimental days (10,149 ± 831 compared with 11,931 ± 896 kJ; P < 0.01), and daily EI remained lower when the PPX snack was consumed during the free-living part of the intervention (7904 ± 610 compared with 9041 ± 928 kJ; P < 0.05). The PPX snack was associated with lower glucose and ghrelin and higher glucagon-like peptide 1 and peptide tyrosine-tyrosine responses. Conclusion: The manipulation of the composition of foods consumed as snacks is an effective way to limit subsequent EI. This trial was registered at clinicaltrials.gov as NCT01927926. [ABSTRACT FROM AUTHOR]

Background: The long-term impact of early malnutrition on human capital outcomes remains unclear, and existing evidence has come largely from observational studies. Objective: We compared the impact of a nutritional supplement given during pregnancy or lactation in rural Gambia on educational performance and cognitive ability in offspring at their maturity. Design: This study was a follow-up of a randomized trial of prenatal high protein and energy supplementation conducted between 1989 and 1994. Subjects were 16-22 y of age at follow-up, and information was collected on schooling achievement and cognitive ability by using the Raven's progressive matrices test, Mill Hill vocabulary test, and forward and backward digit-span tests. Results: A total of 1459 individuals were traced and interviewed and represented 71% of the original cohort and 81% of the surviving cohort. There was no difference in cognitive ability or educational attainment between treatment groups by using any of the methods of assessment. Conclusion: We have shown little evidence to support a long-term effect of prenatal protein-energy supplementation compared with supplementation during lactation on cognitive development in rural Gambians. This trial was registered at http://www.controlled-trials.com as ISRCTN72582014 [ABSTRACT FROM AUTHOR]

Background: Twin and family studies that estimated the heritability of daily physical activity have been limited by poor measurement quality and a small sample size. Objective: We examined the heritability of daily physical activity and sedentary behavior assessed objectively by using combined heart rate and movement sensing in a large twin study. Design: Physical activity traits were assessed in daily life for a mean (±SD) 6.7 ± 1.1 d in 1654 twins from 420 monozygotic and 352 dizygotic same-sex twin pairs aged 56.3 ± 10.4 y with body mass index (in kg/m²) of 26.1 ± 4.8. We estimated the average daily movement, physical activity energy expenditure, and time spent in moderate-to-vigorous intensity physical activity and sedentary behavior from heart rate and acceleration data. We used structural equation modeling to examine the contribution of additive genetic, shared environmental, and unique environmental factors to between-individual variation in traits. Results: Additive genetic factors (ie, heritability) explained 47% of the variance in physical activity energy expenditure (95% CI: 23%, 53%) and time spent in moderate-to-vigorous intensity physical activity (95% CI: 29%, 54%), 35% of the variance in acceleration of the trunk (95% CI: 0%, 44%), and 31% of the variance in the time spent in sedentary behavior (95% CI: 9%, 51%). The remaining variance was predominantly explained by unique environmental factors and random error, whereas shared environmental factors played only a marginal role for all traits with a range of 0-15%. Conclusions: The between-individual variation in daily physical activity and sedentary behavior is mainly a result of environmental influences. Nevertheless, genetic factors explain up to one-half of the variance, suggesting that innate biological processes may be driving some of our daily physical activity. [ABSTRACT FROM AUTHOR]

The diversity of the associations of dietary glycaemic index (GI) and glycaemic load (GL) with dietary intake and body fatness observed in epidemiological studies may be partly due to the differences in underlying dietary intake patterns. We examined the cross-sectional associations of dietary GI and GL with food and nutrient intakes and indices of body fatness in 818 children aged 4–10 years and 818 adolescents aged 11–18 years in Britain, based on the data from the National Diet and Nutrition Survey. Dietary intake was assessed using a 7 d weighed dietary record. Overweight was defined as BMI ≥ 85th percentile of the age- and sex-specific British growth reference data. Central obesity was defined as waist:height ratio (WHtR) ≥ 0·5 (adolescents only). Breads, breakfast cereals and potatoes were the positive predictive food groups for dietary GI, while dairy products, fruit juice, other cereals and fruit were the negative predictors. Dietary GL was closely correlated with carbohydrate intake. Dietary GI showed no associations with overweight or central obesity. Conversely, dietary GL showed an independent association with a higher risk of overweight in children and a higher risk of central obesity (but not overweight) in adolescents. However, dietary GI and GL were not associated with BMI z-score in children and adolescents or WHtR in adolescents. In conclusion, the present study showed that dietary GL was independently associated with overweight in children and with central obesity in adolescents. Nevertheless, given no associations when body fatness measures were treated as continuous variables, the results must be interpreted cautiously. [ABSTRACT FROM PUBLISHER]

The n-3 PUFA are a unique class of fatty acids that cannot be manufactured by the body, and must be acquired via dietary sources. In the UK, as well as in other Western nations, these ‘essential’ fatty acids are consumed in quantities that fall below government guidelines. The present study explored the effects of 12 weeks' dietary supplementation with 1 g/d of two types of fish oil (FO; DHA-rich and EPA-rich) in 159 healthy young adults aged 18–35 years. An assessment of performance on a battery of computerised cognitive tasks and mood measures took place before and following the 12-week treatment regimen. Venous blood samples were also supplied by participants at both time points which were later analysed for serum fatty acid concentrations. Despite good adherence to the study protocol – as reflected in increased concentrations of n-3 serum fatty acids – compared with placebo, the observed effects of both active treatments were minimal. The only finding of note revealed that supplementation with EPA-rich FO may reduce subjective mental fatigue at times of high cognitive demand, although further investigation is required. These findings, taken together with other recent reports of null effects, suggest that dietary supplementation with n-3 PUFA in healthy, normally developing and impairment-free populations is unlikely to result in cognitive enhancement. [ABSTRACT FROM PUBLISHER]

The use of religious/spiritual resources may increase when dealing with the stress of a cancer diagnosis. However, there has been very little research conducted into changes in religious/spiritual beliefs and practices as a result of a cancer diagnosis outside the USA. The aim of this study was to examine the impact of a breast cancer diagnosis on patients' religious/spiritual beliefs and practices in the UK where religious practice is different. The study used two methods. One compared the religious/spiritual beliefs and practices of 202 patients newly diagnosed with breast cancer with those of a control group of healthy women ( n = 110). The other examined patients' perceived change in religious/spiritual beliefs and practices at the time of surgery with those in the year prior to surgery. The aspects of religiousness/spirituality assessed were: levels of religiosity/spirituality, strength of faith, belief in God as well as private and public practices. Patient's perceived their belief in God, strength of faith and private religious/spiritual practices to have significantly increased shortly after surgery compared with the year prior to surgery. However, there were no significant differences in religious/spiritual beliefs and practices between patients and healthy participants. Change scores demonstrated both a reduction and an increase in religious/spiritual beliefs and practices. Although belief in God, strength of faith and private religious/spiritual practices were perceived by patients to be significantly higher after their cancer diagnosis, no significant differences in religious/spiritual beliefs and practices were found between the cancer group at the time of surgery and the control group. Different methodologies appear to produce different results and may explain contradictions in past US studies. Limitations of this study are discussed and suggestions for future research are made. [ABSTRACT FROM AUTHOR]

Context: Cooling the neck region can improve the ability to exercise in a hot environment. It might improve performance by dampening the perceived level of thermal strain, allowing individuals to override inhibitory signals. Objective: To investigate whether the enhanced ability to exercise in a hot environment observed when cooling the neck region occurs because of dampening the perceived level of thermal strain experienced and the subsequent overriding of inhibitory signals. Design: Crossover study. Setting: Walk-in environmental chamber. Patients or Other Participants: Eight endurance-trained, nonacclimated men (age = 26 ± 2 years, height = 1.79 ± 0.04 m, mass = 77.0 ± 6.2 kg, maximal oxygen uptake [VO2max] = 56.2 ± 9.2 mL·kg-1·min-1) participated. Intervention(s): Participants completed 4 running tests at approximately 70% VO2max to volitional exhaustion: 2 familiarization trials followed by 2 experimental trials (cooling collar [CC] and no collar [NC]). Trials were separated by 7 days. Familiarization and NC trials were performed without a collar and used to assess the test variability. Main Outcome Measure(s): Time to volitional exhaustion, heart rate, rectal temperature, neck skin temperature, rating of perceived exertion, thermal sensation, and feeling scale (pleasure/displeasure) were measured. Results: Time to volitional exhaustion was increased by 13.5% ± 3.8% (CC = 43.15 ± 12.82 minutes, NC = 38.20 ± 11.70 minutes; t7 = 9.923, P < .001) with the CC, which reduced mean neck skin temperature throughout the test (P < .001). Participants terminated exercise at identical levels of perceived exertion, thermal sensation, and feeling scale, but the CC enabled participants to tolerate higher rectal temperatures (CC = 39.61 °C ± 0.45°C, NC = 39.18°C ± 0.7°C; t7 = -3.217, P = .02) and heart rates (CC = 181 ± 6 beats/min, NC = 178 ± 9 beats/min; t7 = -2.664, P = .03) at the point of termination. Conclusions: Cooling the neck increased the time taken to reach volitional exhaustion by dampening the perceived levels of thermal strain. [ABSTRACT FROM AUTHOR]