Coffee,tea, caffeine,and risk of hypertension: The Singapore Chinese Health Study

Purpose

The relationship between coffee and tea, and risk of hypertension remains controversial in Western populations. We investigated these associations in an Asian population.

Methods

The Singapore Chinese Health Study is a population-based prospective cohort that recruited 63,257 Chinese aged 45–74 years and residing in Singapore from 1993 to 1998. Information on consumption of coffee, tea, and other lifestyle factors was collected at baseline, and self-reported physician-diagnosed hypertension was assessed during two follow-up interviews (1999–2004, 2006–2010).

Results

We identified 13,658 cases of incident hypertension after average 9.5 years. Compared to those who drank one cup of coffee/day, the hazard ratios (HR) and 95% confidence intervals (CI) were 0.87 (0.83–0.91) for <weekly drinkers and 0.93 (0.86–1.00) for ≥3 cups/day drinkers. Compared to <weekly drinkers, daily drinkers of black or green tea had slight increase in risk, but these risk estimates were attenuated and became non-significant after adjustment for caffeine. After adjusting for coffee, there was a stepwise dose–response relationship between caffeine intake and hypertension risk; compared to the lowest intake (<50 mg/day), those in the highest intake (≥300 mg/day) had a 16% increase in risk; HR 1.16, 95% CI 1.04–1.31 (p trend?=?0.02).

Conclusions

Drinking coffee <1 cup/week or ≥3 cups/day had lower risk than drinking one cup/day. Caffeine may account for increased risk in daily tea drinkers and in those who drank one cup of coffee/day. The inverse U-shaped association with coffee suggests that at higher doses, other ingredients in coffee may offset the effect of caffeine and confer benefit on blood pressure.

     

Pre-pregnancy caffeine and caffeinated beverage intake and risk of spontaneous abortion

Purpose

To investigate the relation between pre-pregnancy caffeine and caffeinated beverage intake and risk of spontaneous abortion (SAB).

Methods

Our prospective cohort study included 15,590 pregnancies from 11,072 women with no history of SAB in the Nurses’ Health Study II (1991–2009). Beverage intake was assessed every 4 years using a validated questionnaire. Pregnancies were self-reported with case pregnancies lost spontaneously at <20 weeks gestation. Multivariable log-binomial regression models with generalized estimating equations were used to estimate the relative risks (RRs) and 95 % confidence intervals (CIs).

Results

There was a positive linear trend across categories of pre-pregnancy caffeine intake and risk of SAB such that women consuming >400 mg/day had 1.11 (95 % CI 0.98, 1.25) times the risk of SAB compared to women consuming <50 mg/day (p trend = 0.05). Total coffee intake had a positive, linear association with SAB. Compared to women with no pre-pregnancy coffee intake, women consuming ≥4 servings/day had a 20 % (6, 36 %) increased risk of SAB (p trend = 0.01). There was no difference in the association between caffeinated and decaffeinated coffee and risk of SAB. Pre-pregnancy intake of caffeinated tea, caffeinated soda, and decaffeinated soda had no association with SAB.

Conclusions

Pre-pregnancy coffee consumption at levels ≥4 servings/day is associated with increased risk of SAB, particularly at weeks 8–19.

     

Optimal nutrition and the ever-changing dietary landscape: a conference report

Purpose

Laboratory studies suggested that caffeine and other nutrients contained in coffee and tea may protect against non-melanoma skin cancer (NMSC). However, epidemiological studies conducted so far have produced conflicting results.

Methods

We performed a literature review and meta-analysis of observational studies published until February 2016 that investigated the association between coffee and tea intake and NMSC risk. We calculated summary relative risk (SRR) and corresponding 95 % confidence intervals (95 % CI) by using random effects with maximum likelihood estimation.

Results

Overall, 37,627 NMSC cases from 13 papers were available for analysis. Intake of caffeinated coffee was inversely associated with NMSC risk (SRR for those in the highest vs. lowest category of intake: 0.82, 95 % CI 0.75–0.89, I ² = 48 %), as well as intake of caffeine (SRR 0.86, 95 % CI 0.80–0.91, I ² = 48 %). In subgroup analysis, these associations were limited to the basal cell cancer (BCC) histotype. There was no association between intake of decaffeinated coffee (SRR 1.01, 95 % CI 0.85–1.21, I ² = 0) and tea (0.88, 95 % CI 0.72–1.07, I ² = 0 %) and NMSC risk. There was no evidence of publication bias affecting the results. The available evidence was not sufficient to draw conclusions on the association between green tea intake and NMSC risk.

Conclusions

Coffee intake appears to exert a moderate protective effect against BCC development, probably through the biological effect of caffeine. However, the observational nature of studies included, subject to bias and confounding, suggests taking with caution these results that should be verified in randomized clinical trials.

     

Discrepancy in socioeconomic status does not fully explain the variation in diet quality between consumers of different coffee types

Purpose

Habitual consumers of different coffee types may vary in socioeconomic status (SES), which is an important determinant of diet quality. Nonetheless, research on diet quality among coffee consumers was scarce. We aimed to compare the diet quality of coffee consumers with different preferences towards coffee type and additive usage.

Methods

In this cross-sectional analysis, intake data of food, coffee, and additive usage from the adult respondents of the 2011–2012 Australian Health Survey were used. Participants were grouped according to the type of coffee (espresso and ground coffee, E&G; coffee made from coffee mixes and instant coffee, M&I; non-consumers, NC) and additives (milk, sugar, and intense sweetener) consumed. Adjusted food group intake was compared between consumption groups using general linear model.

Results

E&G drinkers had better SES than M&I and NC. After adjusting for covariates, the mean dairy intake of E&G drinkers was 22.2% higher than M&I drinkers (p < 0.001) and 33.1% higher than NC (p < 0.001). Mean discretionary food intake of E&G drinkers was 12.1% lower than M&I (p = 0.003) and 12.3% lower than NC (p = 0.001). In terms of additive usage, non-users of coffee additive had the lowest dairy food intake and the highest discretionary food intake.

Conclusions

Coffee consumers’ different preferences towards coffee type and additive usages reflected significant variations in their diet quality, even after adjustment of SES. Therefore, future epidemiological studies should consider separating coffee drinkers according to their habitual consumption of different types of coffee.

     

Coffee,Hunger, and Peptide YY

Objective: There is evidence from several empirical studies suggesting that coffee may help people control body weight. Our objective was to assess the effects of caffeine, caffeinated coffee, and decaffeinated coffee, both alone and in combination with 75 g of glucose, on perceived hunger and satiety and related peptides.

Methods: We conducted a placebo-controlled single-blinded randomized 4-way crossover trial. Eleven healthy male volunteers (mean age, 23.5 ± 5.7 years; mean BMI, 23.6 ± 4.2 kg/m²) ingested 1 of 3 test beverages (caffeine in water, caffeinated coffee, or decaffeinated coffee) or placebo (water), and 60 minutes later they ingested the glucose. Eight times during each laboratory visit, hunger and satiety were assessed by visual analog scales, and blood samples were drawn to measure 3 endogenous peptides associated with hunger and satiety: ghrelin, peptide YY (PYY), and leptin.

Results: Compared to placebo, decaffeinated coffee yielded significantly lower hunger during the whole 180-minute study period and higher plasma PYY for the first 90 minutes (p < 0.05). Caffeine in water had no effects on hunger or PYY. Caffeinated coffee showed a pattern between that of decaffeinated coffee and caffeine in water. These findings suggest that one or more noncaffeine ingredients in coffee may have the potential to decrease body weight. Glucose ingestion did not change the effects of the beverages.

Conclusions: Our randomized human trial showed that decaffeinated coffee can acutely decrease hunger and increase the satiety hormone PYY.     

Serum gamma-glutamyltransferase is inversely associated with dietary total and coffee-derived polyphenol intakes in apparently healthy Japanese men

Purpose

Serum γ-glutamyltransferase (GGT) has been proposed as a marker of oxidative stress. Here, we examined the association between serum GGT and the dietary intake of polyphenols, which have antioxidant properties.

Methods

A cross-sectional survey including 7960 apparently healthy Japanese men (aged 22–86 years) who participated in health checkups was conducted in Shizuoka, Japan. We analyzed these subjects’ clinical serum parameters and lifestyle factors, including dietary polyphenol intake, which was evaluated by a self-administered questionnaire and by matching the subjects’ food consumption data with our original polyphenol content database.

Results

The average intake of polyphenols was 1157?±?471 mg/day, and green tea was the largest source of polyphenols at 40%, followed by coffee at 36%. Dividing the population according to quintiles of total polyphenol intake, the difference in polyphenol intake from coffee between the groups was much greater than the difference in polyphenol intake from green tea. The analysis of the association between polyphenol intake and biological parameters showed a significant negative association between polyphenol intake and the levels of systolic and diastolic blood pressure (SBP and DBP), GGT, and alanine aminotransferase (ALT) after adjusting for age, smoking habit, energy intake and alcohol intake. The GGT levels were inversely associated with the polyphenol intake from coffee, but not with that from green tea. Multivariable linear regression analyses demonstrated that the subjects’ GGT levels were negatively and independently associated with their polyphenol intake.

Conclusions

The intake of total polyphenol including coffee as a major contributor is inversely associated with the serum GGT concentration in Japanese males.

     

The apolipoprotein E polymorphism and the cholesterol-raising effect of coffee

Background

The response of serum cholesterol to diet may be affected by the apolipoprotein E (APOE) ε2/ε3/ε4 polymorphism, which also is a significant predictor of variation in the risk of coronary heart disease (CHD) and CHD death. Here, we test the hypothesis that the APOE polymorphism may modulate the cholesterol-raising effect of coffee.

Objective

We determined the effect of a coffee abstention period and a daily intake of 600 mL coffee on serum cholesterol and triglycerides with respect to the APOE polymorphism.

Design

121 healthy, non-smoking men (22%) and women (78%) aged 29–65 years, took part in a study with four intervention periods: 1 and 3) a coffee free period of three weeks, 2 and 4) 600 mL coffee/day for four weeks.

Results

APOE ε 2 positive individuals had significantly lower total cholesterol concentration at baseline (4.68 mmol/L and 5.28 mmol/L, respectively, p = 0.01), but the cholesterol-raising effect of coffee was not influenced significantly by APOE allele carrier status.

Conclusions

The APOE ε 2 allele is associated with lower serum cholesterol concentration. However, the APOE polymorphism does not seem to influence the cholesterol-raising effect of coffee.

     

Estimated dietary intake and major food sources of polyphenols in elderly of Viçosa,Brazil: a population-based study

Purpose

Epidemiological studies have remarked the beneficial role that polyphenols may have in the elderly population such as cancer and cardiovascular disease prevention. This is particularly relevant considering the global tendency of population aging. Data on polyphenol intake in the elderly population are scarce and usually provide partial information—only for some polyphenol classes. The aim of this study was to estimate the intake of polyphenols and its major dietary contributors in the population of Viçosa.

Methods

A cross-sectional population-based survey including 620 elderly was conducted in Viçosa, Brazil. Food intake was estimated by recall of habitual consumption (RHC). Polyphenol intake was calculated by matching food consumption data from the RHC with the polyphenol content in foods listed in the Phenol-Explorer database.

Results

The average total polyphenol intake was 1198.6 mg/day (533.7 mg/day as aglycone). The main polyphenol classes were phenolic acids (729.5 mg/day) and flavonoids (444.7 mg/day). The main dietary contributors for total polyphenols were coffee (45.8%), beans (32.8%) and polenta (1.3%). A total of 292 polyphenols divided in 14 classes and 23 subclasses were found. The individual compounds with the highest intake were isomers of chlorogenic acid (i.e., 5-caffeoylquinic acid, 4-caffeoylquinic acid and 3-caffeoylquinic acid) among hydroxycinnamic acids that largely originated from coffee.

Conclusions

The data reported here can be used to evaluate the association between the amount and type of ingested polyphenols and health outcomes in epidemiological studies in order to eventually establish nutritional recommendations.

     

Energy drinks and their component modulate attention,memory, and antioxidant defences in rats

Purpose

This study aimed to evaluate the effects of the subchronic consumption of energy drinks and their constituents (caffeine and taurine) in male Wistar rats using behavioural and oxidative measures.

Methods

Energy drinks (ED 5, 7.5, and 10 mL/kg) or their constituents, caffeine (3.2 mg/kg) and taurine (40 mg/kg), either separately or in combination, were administered orally to animals for 28 days. Attention was measured though the ox-maze apparatus and the object recognition memory test. Following behavioural analyses, markers of oxidative stress, including SOD, CAT, GPx, thiol content, and free radicals, were measured in the prefrontal cortex, hippocampus, and striatum.

Results

The latency time to find the first reward was lower in animals that received caffeine, taurine, or a combination of both (P = 0.003; ANOVA/Bonferroni). In addition, these animals took less time to complete the ox-maze task (P = 0.0001; ANOVA/Bonferroni), and had better short-term memory (P < 0.01, Kruskal–Wallis). The ED 10 group showed improvement in the attention task, but did not differ on other measures. In addition, there was an imbalance in enzymatic markers of oxidative stress in the prefrontal cortex, the hippocampus, and the striatum. In the group that received both caffeine and taurine, there was a significant increase in the production of free radicals in the prefrontal cortex and in the hippocampus (P < 0.0001; ANOVA/Bonferroni).

Conclusions

Exposure to a combination of caffeine and taurine improved memory and attention, and led to an imbalance in the antioxidant defence system. These results differed from those of the group that was exposed to the energy drink. This might be related to other components contained in the energy drink, such as vitamins and minerals, which may have altered the ability of caffeine and taurine to modulate memory and attention.

     

Coffee and oxidative stress: a human intervention study

Purpose

Coffee is known to contain phytochemicals with antioxidant potential. The aim of this study was to investigate possible antioxidant effects of coffee in healthy human volunteers.

Methods

A placebo-controlled intervention trial was carried out on 160 healthy human subjects, randomised into three groups, receiving 3 or 5 cups of study coffee or water per day, for 8 weeks. Blood samples were taken before, during, and after the intervention. Serum was used for analysis of blood lipids and standard clinical chemistry analytes. Peripheral blood mononuclear cells were isolated, and DNA damage (strand breaks and oxidised bases) was measured with the comet assay. The lipid oxidation product isoprostane 8-iso-PGF2α was assayed in urine samples by LC–MS/MS.

Results

There was no significant effect of coffee consumption on the markers of oxidation of DNA and lipids. Creatinine (in serum) increased by a few per cent in all groups, and the liver enzyme γ-glutamyl transaminase was significantly elevated in serum in the 5 cups/day group. Other clinical markers (including glucose and insulin), cholesterol, triacylglycerides, and inflammatory markers were unchanged. There was no effect of coffee on blood pressure.

Conclusion

In a carefully controlled clinical trial with healthy subjects, up to 5 cups of coffee per day had no detectable effect, either beneficial or harmful, on human health.

     

Media influence and body satisfaction among adolescent females,Minia, Egypt

Aim

Body dissatisfaction is an important component of a variety of prevalent health problems. This study aimed to assess the media influences on body dissatisfaction among female college students.

Subjects and methods

This study included a sample of 408 adolescent females who were chosen randomly from Minia University and completed a survey using the the Sociocultural Attitudes Towards Appearance Scale (SATAQ-4) and Body Shape Questionnaire (BSQ) in the period from 1 March to 1 April 2017. In addition, their body mass index (BMI) was measured.

Results

It was found that adolescents who showed marked concern with body shape had higher SATAQ-4 scores. The independent variables (BMI, SATAQ total score and its subscales) explained 58% of the variance in body shape dissatisfaction. The most significant predictors of body dissatisfaction were BMI and subjective feelings of media pressure to have an ideal appearance (β?=?0.38 and 0.31, respectively).

Conclusion

There was a relation between media influence and body dissatisfaction in this sample of Egyptian female students. Media literacy training could represent a promising approach to eating and body disturbance prevention.

     

The Effects of Green Tea Extract on Working Memory in Healthy Women

Objectives

This study aimed to examine the effects of green tea extract on working memory in healthy younger (21 - 29 y) and older (50 - 63 y) women.

Design

A single-blind, placebo-controlled, crossover design was used.

Setting

A university laboratory.

Participants

Twenty non-smoking Caucasian women were recruited in the younger (10) and older (10) age group.

Intervention

Subjects received 5.4 g green tea extract (at least 45% epigallocatechin-3-gallate) or placebo (cornstarch) within a 24-hour period.

Measurements

Working memory was measured by reading span and N-back task paradigm. Blood sample (20 mL) was collected and measured for plasma malondialdehyde (MDA) and total antioxidant capacity (TEAC) concentration. A 24-hour recall was conducted for each treatment period to ensure similar dietary patterns.

Results

Green tea extract significantly improved reading span performance in older women, indicated by higher absolute and partial scores of reading span. No significant changes were observed in the younger group. N-back latencies and accuracies were not significantly different after green tea treatment in either age group. Plasma concentration of MDA and TEAC were not different after green tea extract in either group.

Conclusion

Acute supplementation of decaffeinated green tea extract may enhance working memory capacity of women between 50 to 63 years of age. This study provides preliminary evidence that consumption of green tea extract may enhance the cognitive performance in older adults and thus provide potential chemopreventive benefits in this group. The mechanism should be explored in future research.

     

Multidimensional evaluation of endogenous and health factors affecting food preferences,taste and smell perception

Objective

This study, by taking a holistic approach, investigates the relationships between taste, smell sensitivity and food preference with prognostic (endogenous and health) factors including age, gender, genetic taste markers, body mass, cigarette smoking, and number of drugs used.

Design

Cross sectional study.

Setting

Northern Italy.

Participants

203 healthy subjects (160 women/43 men; mean age: 58.2±19.8 years) were examined.

Measurements

Individual taste sensitivity was determined by saccharose, sodium chloride, acetic acid and caffeine solutions and by 6-n-propylthiouracil (PROP) responsiveness test. Olfactory sensitivity has been assessed by «Sniffin’ Sticks». Four tag Single nucleotide polymorphisms (SNPs) in regions of interest were genotyped. Factor analysis and multivariate regression were performed for scaling food preferences and screening prognostic factors, respectively.

Results

Increasing age is associated with decreased responsiveness to NaCl (P=0.001), sweet solutions (P=0.044), and smell perception (P<0.001). Concerning the food preferences, elderly like the “vegetables” and “fruits” but dislike “spicy” more than younger. Regarding number of drugs taken, there is a significant negative effect on smell perception (P<0.001). In addition, drugs reduce both the “vegetables foods” score (P=0.002) and the “milk-product foods” score (P=0.027). With respect to Body Mass Index (BMI), only a significant effect was shown, on sweet perception (P=0.006). Variation in taste receptor genes can give rise to differential perception of sweet, acid and bitter tastes. No effect of gender and smoking was observed.

Conclusions

Our study suggested that age, genetic markers, BMI and drugs use are the factors which affect taste and smell perception and food preferences.

     

Associations between dietary patterns,socio-demographic factors and anthropometric measurements in adult New Zealanders: an analysis of data from the 2008/09 New Zealand Adult Nutrition Survey

Purpose

To investigate associations between dietary patterns, socio-demographic factors and anthropometric measurements in adult New Zealanders.

Methods

Dietary patterns were identified using factor analysis in adults 15 years plus (n?=?4657) using 24-h diet recall data from the 2008/09 New Zealand Adult Nutrition Survey. Multivariate regression was used to investigate associations between dietary patterns and age, gender and ethnicity. After controlling for demographic factors, associations between dietary patterns and food insecurity, deprivation, education, and smoking were investigated. Associations between dietary patterns and body mass index and waist circumference were examined adjusting for demographic factors, smoking and energy intake.

Results

Two dietary patterns were identified. ‘Healthy’ was characterised by breakfast cereal, low fat milk, soy and rice milk, soup and stock, yoghurt, bananas, apples, other fruit and tea, and low intakes of pies and pastries, potato chips, white bread, takeaway foods, soft drinks, beer and wine. ‘Traditional’ was characterised by beef, starchy vegetables, green vegetables, carrots, tomatoes, savoury sauces, regular milk, cream, sugar, tea and coffee, and was low in takeaway foods. The ‘healthy’ pattern was positively associated with age, female gender, New Zealand European or other ethnicity, and a secondary school qualification, and inversely associated with smoking, food insecurity, area deprivation, BMI and waist circumference. The ‘traditional’ pattern was positively associated with age, male gender, smoking, food insecurity and inversely associated with a secondary school qualification.

Conclusions

A ‘Healthy’ dietary pattern was associated with higher socio-economic status and reduced adiposity, while the ‘traditional’ pattern was associated with lower socio-economic status.

     

Acute effects of caffeine-containing energy drinks on physical performance: a systematic review and meta-analysis

Purpose

Caffeine-containing energy drinks (EDs) are currently used as ergogenic aids to improve physical performance in a wide variety of sport disciplines. However, the outcomes of previous investigations on this topic are inconclusive due to methodological differences, especially, in the dosage of the active ingredients and the test used to assess performance.

Methods

We performed a systematic review and meta-analysis of published studies to evaluate the effects of acute ED intake on physical performance. The search for references was conducted in the databases PubMed, ISI Web of Knowledge and SPORTDiscus until December 2015.

Results

Thirty-four studies published between 1998 and 2015 were included in the analysis. Using a random-effects model, effect sizes (ES) were calculated as the standardized mean difference. Overall, ED ingestion improved physical performance in muscle strength and endurance (ES = 0.49; p < 0.001), endurance exercise tests (ES = 0.53; p < 0.001), jumping (ES = 0.29; p = 0.01) and sport-specific actions (ES = 0.51; p < 0.001), but not in sprinting (ES = 0.14; p = 0.06). The meta-regression demonstrated a significant association between taurine dosage (mg) and performance (slope = 0.0001; p = 0.04), but not between caffeine dosage (mg) and performance (slope = 0.0009; p = 0.21).

Conclusion

ED ingestion improved performance in muscle strength and endurance, endurance exercise tests, jumping and sport-specific actions. However, the improvement in performance was associated with taurine dosage.