The effect of caffeinated, non-caffeinated, caloric and non-caloric beverages on hydration

OBJECTIVE: To examine the effect of various combinations of beverages on hydration status in healthy free-living adult males. METHODS: In a counterbalanced, crossover manner, 18 healthy adult males ages 24 to 39, on four separate occasions, consumed water or water plus varying combinations of beverages. Clinical guidelines were used to determine the fluid allowance for each subject. The beverages were carbonated, caffeinated caloric and non-caloric colas and coffee. Ten of the 18 subjects consumed water and carbonated, non-caffeinated, citrus soft drink during a fifth trial. Body weight, urine and blood assays were measured before and after each treatment. RESULTS: Slight body weight loss was observed on all treatments, with an average of 0.30% for all treatments. No differences (p>0.05) among treatments were found for body weight changes or any of the biochemical assays. Biochemical assays conducted on first voids and 24-hour urines included electrolytes, creatine, osmolality and specific gravity. Blood samples were analyzed for hemoglobin, hematocrit. electrolytes, osmolality, urea nitrogen, creatinine and protein. CONCLUSIONS: This preliminary study found no significant differences in the effect of various combinations of beverages on hydration status of healthy adult males. Advising people to disregard caffeinated beverages as part of the daily fluid intake is not substantiated by the results of this study. The across-treatment weight loss observed, when combined with data on fluid-disease relationships, suggests that optimal fluid intake may be higher than common recommendations. Further research is needed to confirm these results and to explore optimal fluid intake for healthy individuals.     

Effects of added glutamate on liking for novel food flavors

Adding glutamate to foods increases their umami quality, their acceptability and their consumption. The functional significance of this palatability is unclear. Other highly palatable substances, e.g. sugar and fats, also increase liking for novel flavors with which they are repeatedly paired, especially when ingested. This is thought to reflect the rewarding effects of sugar and fat energy, post-ingestion. To determine if a liking for novel flavors can also be conditioned using glutamate, 44 subjects rated 10 ml samples of three novel soups for liking and familiarity, both before and after seven daily exposures to each of two soup flavors-one with added monosodium l-glutamate (MSG) (0.5% w/w; MSG+) and one without (MSG-). During exposure, subjects received either a 250 ml bowl of soup (Consume group) or a 10 ml sample (Taste group). There were no significant differences as a function of samples or groups, despite some trends for changes in liking to be higher in the consumed MSG+ condition. In a second experiment, 69 subjects were divided into three groups (Consume MSG+; Consume MSG-; Taste MSG+) in which they received nine exposures to one novel soup flavor. The Consume MSG+ group showed a significantly greater increase in liking than either the Consume MSG- or the Taste MSG+ groups, which did not differ. Changes in familiarity ratings reflected amount consumed, not MSG content. Pairing glutamate with a novel flavor can condition liking for that flavor. While post-ingestive effects of glutamate may be rewarding, flavor conditioning cannot be ruled out.     

Contextual influences on liking and preference

The paper addresses the topic of how much an individual likes a stimulus and also how much that individual prefers it to other stimuli. Research is reviewed showing that the context in which the stimulus is presented affects both liking and preference judgments. Having subjects think of the context stimuli and the test stimuli as being in different categories reduces the impact of the context stimuli on the ratings of the test stimuli and might be used to avoid such context effects in determining liking of and preferences for stimuli.     

Effect of a milk drink supplemented with whey peptides on blood pressure in patients with mild hypertension

BACKGROUND: Inhibition of the angiotensin I-converting enzyme (ACE) is a widely used principle for the treatment of hypertension. Fermentation of milk proteins was shown to lead to the formation of peptides with ACE-inhibiting activity. Milk products with ACE-inhibiting peptides may provide a useful approach to prevent or treat hypertension. AIM OF THE STUDY: To investigate the effect of a milk drink supplemented with whey peptides on blood pressure in mildly hypertensive subjects. METHODS: A randomized, placebo-controlled, double blind clinical trial in two parallel groups was performed. A total of 54 hypertensive patients received either 125 ml of a milk drink supplemented with whey peptides every morning or a control product for 12 weeks after a run-in period of 2 weeks. Previous in vitro tests of the whey powder demonstrated ACE-inhibitory activity. Blood pressure was measured at 0, 2, 4, 8, and 12 weeks. Fasting blood samples were collected at 0, 4, 8, and 12 weeks for analysis of metabolic and inflammatory variables. RESULTS: Resting systolic and diastolic blood pressure values did not change in the milk drink group 144.1 +/- 8.6/91.0 +/- 5.5 mmHg at baseline vs. 143.7 +/- 13.5/90.4 +/- 6.5 mmHg after 12 weeks. In the control group systolic (p = 0.0431) and diastolic (p = 0.0081) blood pressure was significantly reduced 140.6 +/- 11.7/90.3 +/- 5.8 mmHg at baseline vs. 137.0 +/- 14.4/87.7 +/- 6.6 mmHg after 12 weeks. There was no difference between the two groups at any time point. No changes were seen when the results of the 24-h continuous blood pressure monitoring were compared after 12 weeks. No significant changes were detected for circulating levels of selected inflammation markers (interleukin (IL)-6, C-reactive protein (CRP), number of leukocytes, and plasminogen activator inhibitor-1 (PAI-1) as well as for metabolic variables (insulin, plasma glucose, and lipids). CONCLUSIONS: The daily consumption of 125 ml of a milk drink supplemented with whey peptides was not found to reduce blood pressure and/or inflammation markers in mildly hypertensive subjects, although preceding in vitro tests showed a potent ACE-inhibition.     

何首乌饮对衰老大鼠卵巢细胞凋亡的影响

目的:探讨何首乌饮对亚急性衰老大鼠卵巢细胞凋亡相关基因P53和Bcl-2/Bax蛋白表达的影响。方法:采用D-半乳糖连续腹腔注射致亚急性衰老大鼠模型,在造模后以何首乌饮灌胃作为延缓衰老组;造模后应用逆转录聚合酶链反应测定各组P53的mRNA水平;Western Bloting法检测卵巢细胞Bcl-2和Bax f蛋白的表达情况。结果:与正常对照组比较,D-半乳糖致衰老的模型组大鼠卵巢细胞中P53基因和Bax蛋白表达明显上升,Bcl-2蛋白表达显著下降,差异有统计学意义(P<0.01);何首乌饮延缓衰老组较模型组P53基因和Bax蛋白表达明显下降(P<0.01),并上调Bcl-2蛋白的表达,呈现量效关系,以何首乌饮高剂量组效果作用最佳。结论:何首乌饮方剂可能是通过调节卵巢细胞凋亡相关基因和蛋白表达,来延缓衰老大鼠卵巢细胞凋亡的发生。     

Impact of consuming a milk drink containing a probiotic on mood and cognition

OBJECTIVE: The impact on mood and memory of consuming a probiotic containing milk drink, or a placebo, was examined as, previously, a poor mood has been found to correlate with the frequency of constipation. DESIGN: A double-blind placebo-controlled trial with random allocation of subjects. SETTING: Subjects went about their normal life in the community apart from three visits to the laboratory. SUBJECTS: One hundred and thirty-two healthy members of general population, mean age 61.8 years, volunteered in response to local media coverage. One hundred and twenty-four finished the trial. INTERVENTION: For a 3-week period, either a probiotic containing milk drink, or a placebo, were consumed daily. Mood and cognition were measured at baseline, and after 10 and 20 days of consumption. RESULTS: At baseline those who reported themselves to be less frequently constipated were more clearheaded, confident and elated. Although the taking of the probiotic did not generally change the mood, this appeared to be a reflection of the generally good mood in this sample. When those in the bottom third of the depressed/elated dimension at baseline were considered, they selectively responded by reporting themselves as happy rather than depressed after taking the probiotic. The intervention did not, however, influence the reported frequency of defaecation, probably a reflection of the initially low incidence of constipation. An unexpected and possibly chance finding was that the consumption of probiotics resulted in a slightly-poorer performance on two measures of memory. CONCLUSIONS: The consumption of a probiotic-containing yoghurt improved the mood of those whose mood was initially poor. This improvement in mood was not, however, associated with an increased frequency of defaecation.     

Correlation between a liking for fat-rich foods and body fatness in adult Japanese: a gender difference

The aim of the present study was to test the hypothesis that Japanese adults who like fat-rich foods have more body fatness and higher serum lipid levels than those who do not. The subjects were 540 male and 492 female workers under 41 years of age. A self-administered questionnaire determined four levels of liking for fat-rich foods. Anthropometric measurements were employed yielding body mass index (BMI), waist to hip circumference ratio (WHR), and skinfold thickness. Anthropometric values were compared among the levels of liking for fat-rich foods using analysis of covariance. For males, a liking for fat-rich foods was associated with BMI, WHR, whole-body skinfold thickness, and abdominal skinfold thickness (p<0.0001). In particular, those who like fat-rich foods "quite a bit" or "very much" showed significantly higher values than those who answered "no" or "a little". Multiple regression analysis showed that a liking for fat-rich foods explains 7-9% of the variation in the anthropometric indices, even when other lifestyles were taken into account. For females, such findings were not evident. There is a gender difference in the association between a liking for fat-rich foods and body fatness. The difference may be due to a female-specific attitude toward high-calorie foods.     

Effect of a tomato drink intervention on insulin-like growth factor (IGF)-1 serum levels in healthy subjects

There is concern that dietary factors can modulate the insulin-like growth factor (IGF) system. The aim of this work was to evaluate the effect of a tomato drink intervention providing small amounts of lycopene and other carotenoids on serum levels of IGF-1. Twenty healthy young subjects participated in a repeated measure double-blind, cross-over design. Subjects consumed 250 ml of a tomato drink or a placebo drink for 26 days separated by 26 days wash-out. The tomato drink intake increased plasma lycopene, phytoene, phytofluene, and beta-carotene concentrations by 0.22, 0.12, 0.13, and 0.18 micromol/L, respectively (P < 0.05). No significant effect of the tomato drink intake on IGF-1 levels was observed. However, changes in lycopene before and after each experimental period were inversely and significantly correlated with those of IGF-1 (r = -0.33, P < 0.05, N = 20). No correlation was found with the other carotenoids. A significant reduction of IGF-1 serum level (-5.7%) was observed in subjects (n = 11) with the highest plasma lycopene response but also IGF-1 levels following the tomato drink intake (P < 0.05). No effect was evident after the placebo treatment. The results suggest that further exploration of the role of tomato lycopene on IGF-1 modulation both on healthy and on subjects at risk is necessary.     

Effects of a herbal ergogenic drink on cycling performance in young cyclists

It is essential to replace fluids lost so as to remain well hydrated during exercise. The intake of fluids is considered a physiological ergogenic aid to enhance exercise performance. There are currently several products in the market that are believed to have ergogenic properties which act as fluid replacement drinks during exercise. One such drink available in the Malaysian market is 'AgroMas?' herbal drink whose efficacy is yet to be proven. The purpose of this study was, therefore, to evaluate the effects of acute ingestion of this herbal drink (H) or a coloured water placebo (P) on cycling performance. Nine healthy and trained young male cyclists (age: 16.2 ± 0.5 years) exercised on a cycle ergometer at 71.9 ± 0.7% of maximal oxygen consumption (VO2max) until exhaustion on two occasions at 1-week intervals. During each exercise bout, subjects received 3ml kg-1 body weight of H or P every 20 min in a double-blind randomised study design. There was no significant difference between H and P trials in the total work time to exhaustion (83.7 ± 4.6 and 81.5 ± 5.0 min respectively). Changes in oxygen consumption, heart rate and perceived rate of exertion were similar for both types of drinks. These results demonstrate that the herbal drink and the placebo elicited similar physiological responses and exercise performance during endurance cycling. It is therefore concluded that AgroMas? herbal drink and water ingestion resulted in a similar ergogenic response on cycling performance in young cyclists.     

Effect of Red Bull energy drink on repeated Wingate cycle performance and bench-press muscle endurance

The purpose of this study was to determine the effects of Red Bull energy drink on Wingate cycle performance and muscle endurance. Healthy young adults (N = 15, 11 men, 4 women, 21 +/- 5 y old) participated in a crossover study in which they were randomized to supplement with Red Bull (2 mg/kg body mass of caffeine) or isoenergetic, isovolumetric, noncaffeinated placebo, separated by 7 d. Muscle endurance (bench press) was assessed by the maximum number of repetitions over 3 sets (separated by 1-min rest intervals) at an intensity corresponding to 70% of baseline 1-repetition maximum. Three 30-s Wingate cycling tests (load = 0.075 kp/kg body mass), with 2 min recovery between tests, were used to assess peak and average power output. Red Bull energy drink significantly increased total bench-press repetitions over 3 sets (Red Bull = 34 +/- 9 vs. placebo = 32 +/- 8, P %%%lt; 0.05) but had no effect on Wingate peak or average power (Red Bull = 701 +/- 124 W vs. placebo = 700 +/- 132 W, Red Bull = 479 +/- 74 W vs. placebo = 471 +/- 74 W, respectively). Red Bull energy drink significantly increased upper body muscle endurance but had no effect on anaerobic peak or average power during repeated Wingate cycling tests in young healthy adults.     

Ferrous fumarate fortification of a chocolate drink powder.

An evaluation was made into the usefulness of ferrous fumarate as an iron fortificant for an experimental chocolate drink powder targetted to children and adolescents. Organoleptically ferrous furmarate was acceptable when the chocolate drink powder was reconstituted in milk or water that was heated to less than 80 degrees. Unacceptable colour changes occurred, however, when boiling milk or water were used. In human Fe absorption studies when the Fe compounds were added to the chocolate drink immediately before consumption, ferrous fumarate was 3.31% absorbed compared with 2.82% for ferrous sulphate and 2.11% for ferric pyrophosphate. When the Fe compounds were processed during the manufacture of the chocolate drink powder, the absorption of ferrous furmarate was 5.27%, ferrous sulphate 2.62% and ferric pyrophosphate 0.55%. Ascorbic acid had little or no effect on the absorption of ferrous furmarate. It is concluded that food processing can influence the relative absorption of fortification Fe and that, if not reconstituted with boiling milk or water, ferrous fumarate could be a useful compound for the fortification of chocolate drink powders.     

Compensation for age-associated chemosensory losses and its effect on the pleasantness of a custard dessert and a tomato drink

Differences between elderly subjects (n=52, 60-85 years) and young subjects (n=55, 18-35) in their food liking and their olfactory capability were investigated. Two food systems were used: custard desserts and tomato drinks. Flavor enhancement/enrichment, textural change, and/or irritant addition were incorporated as compensatory strategies into these foods. The addition of low concentrations of both cherry flavor and cream flavor to the custard desserts influenced their pleasantness for the majority of the elderly. The addition of cream topping increased the pleasantness of the custard desserts for both the elderly and the young. The elderly equally liked the tomato drinks with no or with low irritant addition, whereas the young generally disliked an irritant addition. However, the food liking of the elderly was not generally increased by these different compensatory strategies. Instead, subgroups were observed for each compensatory strategy, in which applied compensatory strategies led to an increase in product pleasantness. Age-associated losses in olfactory capabilities did not sufficiently explain differences in food liking, as only elderly with similar olfactory capabilities to the young demonstrated a liking of enhanced flavor. The present study does not support the assumption that age-associated impairment in olfactory capability will inevitably lead to changes in food liking.     

Effect of dilution of sports drink on water balance and beverage preference of heat-exposed steel workers

Eight skilled workers engaged in heat-exposed work in front of a blast furnace in a steel factory were asked to drink a sports drink or one of its dilutions of x 2, x 3, or x 5 during a regular daytime shift in the summer of 1999. A regular lunch was taken and the examined beverage was iced and was allowed to be consumed ad libitum. The beverage was changed each day during four days of the experiment without informing the dilution ratio. The non-diluted beverage contained 21 mEq/l of Na+, 5 mEq/l of K+, 6.7 g/dl of carbohydrate. In average, the body temperature measured in the ear canal was elevated by 0.34 degree C, the loss of body weight was 1.77 kg, total beverage intake was 1,875 g, total amount of urine was 291 g, and the total water loss was 3,732 g (1,350-5,810 g) during a single shift. Twenty out of 24 cases experienced more than 1.5% of weight reduction during morning work without noticing any subjective symptoms of dehydration. The amount of weight loss during morning work was significantly smaller when x 2 or x 3 dilution was taken compared to a non-diluted beverage. The mean value of urinary Na+ concentration was decreased after 8 hours of work; however, the difference was not significant. The urinary K+ concentration was significantly increased. When the total amount of urinary sodium excretion in stored urine was calculated, the x 3 dilution recorded the largest amount. Regarding palatability, the x 2 dilution received the best evaluation, whereas all subjects felt the original beverage as too condensed. We did not observe any adverse effect from diluting the sports drink for x 2 or x 3, when supplying them as water and electrolyte replacements for dehydrated steel workers.     

Neatness counts. How plating affects liking for the taste of food

Two studies investigated the effect that the arrangement of food on a plate has on liking for the flavor of the food. Food presented in a neatly arranged presentation is liked more than the same food presented in a messy manner. A third study found that subjects expected to like the food in the neat presentations more than in the messy ones and would be willing to pay more for them. They also indicated that the food in the neat presentations came from a higher quality restaurant and that more care was taken with its preparation than the food in the messy presentations. Only the animal-based food was judged as being more contaminated when presented in a messy rather than a neat way. Neatness of the food presentation increases liking for the taste of the food by suggesting greater care on the part of the preparer. Two mechanisms by which greater care might increase liking are discussed.     

An assessment of liking for sugars using the estimated daily intake scale

Sugar is often used in learning and conditioning studies as an unconditioned stimulus (US) to enhance liking for a flavor mixed with it. To use sugar as a US, participants are selected only if they like the taste of sugar based on their ratings of a sweetened water US during a preexposure trial prior to experimental procedures. This US-only trail introduces a potential sensory bias and can lead to participant attrition when such a trial is conducted the day prior to experimental procedures. The aim of the present study was to construct a brief scale, called the Estimated Daily Intake Scale for Sugar (EDIS-S), to measure a participant's exposure to sugar in their diet. It was hypothesized that exposure to sugar would be positively correlated with liking for sugar. As expected, an 11-item EDIS-S was reliable and significantly correlated with ratings of liking for a sweetened taste solution. Implications for the use of the EDIS-S as an assessment in many areas of research, and as a participant selection tool for conditioning studies are discussed.