Associations between smoking and caffeine consumption in two European cohorts

Mendelian randomization analysis of maternal coffee consumption during pregnancy on offspring neurodevelopmental difficulties in the Norwegian Mother, Father and Child Cohort Study (MoBa)

BACKGROUND

Previous observational epidemiological studies have suggested that coffee consumption during pregnancy may affect fetal neurodevelopment. However, results are inconsistent and may represent correlational rather than causal relationships. The present study investigated whether maternal coffee consumption was observationally associated and causally related to offspring childhood neurodevelopmental difficulties (NDs) in the Norwegian Mother, Father and Child Cohort Study.

METHODS

The observational relationships between maternal/paternal coffee consumption (before and during pregnancy) and offspring NDs were assessed using linear regression analyses (N = 58694 mother-child duos; N = 22 576 father-child duos). To investigate potential causal relationships, individual-level (N = 46 245 mother-child duos) and two-sample Mendelian randomization (MR) analyses were conducted using genetic variants previously associated with coffee consumption as instrumental variables.

RESULTS

We observed positive associations between maternal coffee consumption and offspring difficulties with social-communication/behavioral flexibility, and inattention/hyperactive-impulsive behavior (multiple testing corrected p < 0.005). Paternal coffee consumption (negative control) was not observationally associated with the outcomes. After adjusting for potential confounders (smoking, alcohol, education and income), the maternal associations attenuated to the null. MR analyses suggested that increased maternal coffee consumption was causally associated with social-communication difficulties (individual-level: beta = 0.128, se = 0.043, p = 0.003; two-sample: beta = 0.348, se = 0.141, p = 0.010). However, individual-level MR analyses that modelled potential pleiotropic pathways found the effect diminished (beta = 0.088, se = 0.049, p = 0.071). Individual-level MR analyses yielded similar estimates (heterogeneity p = 0.619) for the causal effect of coffee consumption on social communication difficulties in maternal coffee consumers (beta = 0.153, se = 0.071, p = 0.032) and non-consumers (beta = 0.107, se = 0.134, p = 0.424).

CONCLUSIONS

Together, our results provide little evidence for a causal effect of maternal coffee consumption on offspring NDs.

Genome-wide association studies of coffee intake in UK/US participants of European ancestry uncover cohort-specific genetic associations

Coffee is one of the most widely consumed beverages. We performed a genome-wide association study (GWAS) of coffee intake in US-based 23andMe participants (N = 130,153) and identified 7 significant loci, with many replicating in three multi-ancestral cohorts. We examined genetic correlations and performed a phenome-wide association study across hundreds of biomarkers, health, and lifestyle traits, then compared our results to the largest available GWAS of coffee intake from the UK Biobank (UKB; N = 334,659). We observed consistent positive genetic correlations with substance use and obesity in both cohorts. Other genetic correlations were discrepant, including positive genetic correlations between coffee intake and psychiatric illnesses, pain, and gastrointestinal traits in 23andMe that were absent or negative in the UKB, and genetic correlations with cognition that were negative in 23andMe but positive in the UKB. Phenome-wide association study using polygenic scores of coffee intake derived from 23andMe or UKB summary statistics also revealed consistent associations with increased odds of obesity- and red blood cell-related traits, but all other associations were cohort-specific. Our study shows that the genetics of coffee intake associate with substance use and obesity across cohorts, but also that GWAS performed in different populations could capture cultural differences in the relationship between behavior and genetics.

Lung cancer metabolomics: a pooled analysis in the Cancer Prevention Studies

BACKGROUND

A better understanding of lung cancer etiology and the development of screening biomarkers have important implications for lung cancer prevention.

METHODS

We included 623 matched case-control pairs from the Cancer Prevention Study (CPS) cohorts. Pre-diagnosis blood samples were collected between 1998 and 2001 in the CPS-II Nutrition cohort and 2006 and 2013 in the CPS-3 cohort and were sent for metabolomics profiling simultaneously. Cancer-free controls at the time of case diagnosis were 1:1 matched to cases on date of birth, blood draw date, sex, and race/ethnicity. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression, controlling for confounders. The Benjamini-Hochberg method was used to correct for multiple comparisons.

RESULTS

Sphingomyelin (d18:0/22:0) (OR: 1.32; 95% CI: 1.15, 1.53, FDR = 0.15) and taurodeoxycholic acid 3-sulfate (OR: 1.33; 95% CI: 1.14, 1.55, FDR = 0.15) were positively associated with lung cancer risk. Participants diagnosed within 3 years of blood draw had a 55% and 48% higher risk of lung cancer per standard deviation increase in natural log-transformed sphingomyelin (d18:0/22:0) and taurodeoxycholic acid 3-sulfate level, while 26% and 28% higher risk for those diagnosed beyond 3 years, compared to matched controls. Lipid and amino acid metabolism accounted for 47% to 80% of lung cancer-associated metabolites at P < 0.05 across all participants and subgroups. Notably, ever-smokers exhibited a higher proportion of lung cancer-associated metabolites (P < 0.05) in xenobiotic- and lipid-associated pathways, whereas never-smokers showed a more pronounced involvement of amino acid- and lipid-associated metabolic pathways.

CONCLUSIONS

This is the largest prospective study examining untargeted metabolic profiles regarding lung cancer risk. Sphingomyelin (d18:0/22:0), a sphingolipid, and taurodeoxycholic acid 3-sulfate, a bile salt, may be risk factors and potential screening biomarkers for lung cancer. Lipid and amino acid metabolism may contribute significantly to lung cancer etiology which varied by smoking status.

Causal association of genetically determined caffeine intake from tea or coffee with bone health: a two-sample Mendelian randomization study

BACKGROUND

Relationship of caffeine intake and consumption of caffeinated beverages, such as tea and coffee, with bone health remains controversial. This study aimed to evaluate whether genetically determined caffeine intake from tea or coffee has causal effects on overall total body bone mineral density (TB-BMD) and fracture. We also assessed the association with TB-BMD in five age strata.

METHODS

Using two-sample Mendelian randomization approach, summary statistics were retrieved from genome-wide association studies (GWAS)/GWAS meta-analyses of caffeine intake from tea (n = 395 866)/coffee (n = 373 522), TB-BMD (n = 66 628), and fracture (n = 426 795). Inverse variance weighted method was adopted as the main univariable analysis. Multivariable analysis was conducted to evaluate whether the causal effect is independent.

RESULTS

In univariable analysis, genetically determined caffeine intake from tea had positive association with overall TB-BMD (per SD increase in genetically determined caffeine intake, beta of TB-BMD [in SD]: 0.166; 95% confidence interval (CI): 0.006-0.326) and inverse association with fracture (OR = 0.79; 95% CI: 0.654-0.954). Genetically determined caffeine intake from coffee was also positively associated with overall TB-BMD (beta = 0.231; 95% CI: 0.093-0.369). The association remained significant after adjustment for smoking in multivariable analysis. Genetically determined caffeine intake from tea or coffee was both positively associated with TB-BMD in the age strata of 45-60 years, but we lacked evidence of association in other strata.

CONCLUSIONS

Genetically, caffeine intake from tea or coffee may be beneficial to bone health. Due to the ascertainment method of caffeine intake from tea, our study also implied genetically higher tea consumption may improve TB-BMD and lower fracture risk.

Plasma metabolites of a healthy lifestyle in relation to mortality and longevity: Four prospective US cohort studies

BACKGROUND

A healthy lifestyle is associated with a lower premature mortality risk and with longer life expectancy. However, the metabolic pathways of a healthy lifestyle and how they relate to mortality and longevity are unclear. We aimed to identify and replicate a healthy lifestyle metabolomic signature and examine how it is related to total and cause-specific mortality risk and longevity.

METHODS

In four large cohorts with 13,056 individuals and 28-year follow-up, we assessed five healthy lifestyle factors, used liquid chromatography mass spectrometry to profile plasma metabolites, and ascertained deaths with death certificates. The unique healthy lifestyle metabolomic signature was identified using an elastic regression. Multivariable Cox regressions were used to assess associations of the signature with mortality and longevity.

FINDINGS

The identified healthy lifestyle metabolomic signature was reflective of lipid metabolism pathways. Shorter and more saturated triacylglycerol and diacylglycerol metabolite sets were inversely associated with the healthy lifestyle score, whereas cholesteryl ester and phosphatidylcholine plasmalogen sets were positively associated. Participants with a higher healthy lifestyle metabolomic signature had a 17% lower risk of all-cause mortality, 19% for cardiovascular disease mortality, and 17% for cancer mortality and were 25% more likely to reach longevity. The healthy lifestyle metabolomic signature explained 38% of the association between the self-reported healthy lifestyle score and total mortality risk and 49% of the association with longevity.

CONCLUSIONS

This study identifies a metabolomic signature that measures adherence to a healthy lifestyle and shows prediction of total and cause-specific mortality and longevity.

FUNDING

This work was funded by the NIH, CIHR, AHA, Novo Nordisk Foundation, and SciLifeLab.

Prevalence of energy drink consumption world-wide: A systematic review and meta-analysis

BACKGROUND AND AIMS

The increasing market for energy drinks (EDs) in recent years, as well as the health risks caused by their consumption, prompt calls to estimate the prevalence of ED use among different countries. This systematic review and meta-analysis aimed to synthesize the prevalence of ED use in different continents and age groups.

METHOD

We searched two databases (i.e. PubMed and PsycInfo) on 31 March 2023 to identify studies reporting the prevalence of ED use. A total of 192 studies (196 distinct samples; n = 1 120 613; 53.37% males) from the United States, Europe, Asia, Oceania and Africa were included in the analysis. A random-effects model was applied to estimate the overall pooled prevalence at several time-periods. Subgroup analyses were performed to provide prevalence based on continent and age group. The quality of articles was assessed using Joana Brigg's Institute (JBI) critical appraisal checklist. Measurements included prevalence of ED use (i.e. life-time, past 12 months, past 30 days, past 7 days and daily use), continent and age group (i.e. children, adolescents, young adults and adults).

RESULTS

The life-time ED use world-wide-pooled prevalence was estimated to be 54.7% [95% confidence interval (CI) = 48.8-60.6; I2  = 99.80], 43.4% (95% CI = 36.1-50.6; I2  = 99.92) in the past 12 months, 32.3% (95% CI = 28.8-35.8; I2  = 99.82) in the past 30 days, 21.6% (95% CI = 18.7-24.5; I2  = 99.95) in the past 7 days and 8.82% (95% CI = 6.3-11.4; I2  = 99.95) daily ED use. Subgroups analyses showed significant differences in ED life-time use within age groups (P = 0.002) and continents (P = 0.035).

CONCLUSIONS

The world-wide prevalence of energy drink use appears to be high, particularly among adolescents and young adults.

GRADE GUIDANCE 38: Updated guidance for rating up certainty of evidence due to a dose-response gradient

INTRODUCTION

This updated guidance from the Grading of Recommendations Assessment, Development, and Evaluation addresses rating up certainty of evidence due to a dose-response gradient (DRG) observed in synthesis of intervention and exposure studies.

STUDY DESIGN AND SETTING

This guidance was developed using iterative discussions and consensus in multiple meetings and was presented to attendees of the Grading of Recommendations Assessment, Development, and Evaluation Working Group meeting for feedback in November 2022 and for final approval in May 2023.

RESULTS

The guidance consists of two steps. The first is to determine whether the DRG is credible. We describe five items for assessing credibility: a) is DRG identified using a proper analytical approach; b) is confounding the cause of the DRG; c) is there serious concern about ecological bias; d) is the DRG consistent across studies; and e) is there indirect evidence supporting the DRG. The first two of these items are the most critical. If the DRG was judged to be credible, then the second step is to apply the DRG domain and consider rating up, but only by one level due to the concern about residual confounding.

CONCLUSION

Systematic review authors should only rate up certainty in evidence when a DRG is deemed credible.

Correlates of Dietary Behaviors Among Young Emirati Males Completing Compulsory Military Service

INTRODUCTION

It is important to understand the correlates of different dietary behaviors in a military context in the United Arab Emirates (UAE) to guide intervention development to prevent and treat obesity as it has a significant impact at the country and regional level. This study aimed to assess different dietary behaviors and their association with potential correlates including age, marital status, educational level, smoking status, screen time, dietary knowledge, eating self-efficacy, and general self-efficacy.

MATERIALS AND METHODS

The study used a cross-sectional design and included 153 (M = 25.9 years, SD = ± 3.2) military recruits completing their basic training at a single military camp in the UAE. Dietary behaviors of these recruits were measured using the Arab Teens Lifestyle Study. Other potential correlates included dietary knowledge, general self-efficacy, and eating efficacy. The ethical approval was obtained from the research ethics committee in the UAE university.

RESULTS

Daily intake of fruits, vegetables, and breakfast was reported by 14.4%, 25.5%, and 22.9% of the military recruits, respectively. Almost half of the recruits (46.4%) consumed sugar-sweetened drinks more than 3 times a week, 39.2% consumed fast food more than 3 times a week, and 37.3% consumed sweets/chocolates more than 3 times a week. Bivariate regression analyses revealed that eating self-efficacy was positively associated with breakfast and dairy food consumption, although it was inversely associated with sugar, fast-food, and French fries intake. Age was significantly and inversely associated with sugar, fast-food, and energy drink intake. Moreover, nutrition knowledge was significantly and positively correlated with vegetable intake and negatively correlated with energy drink consumption. Multiple regressions showed that lower age and lower eating self-efficacy were found to be the main predictors for sugar-sweetened drinks (adjusted R2 = 0.112) and fast-food intake (adjusted R2 = 0.084). Also, a higher dietary knowledge score was a predictor of vegetable intake (adjusted R2 = 0.093), although age and smoking predict energy drink intake (adjusted R2 = 0.225).

CONCLUSIONS

The results show that unhealthy eating patterns are common among new recruits in the UAE military. The study suggests that age, eating self-efficacy, and nutrition knowledge are the main correlates of selected dietary behaviors. Interventions are advised to target these correlates to achieve healthier dietary habits inside the military.

Maternal caffeine consumption during pregnancy and offspring cord blood DNA methylation: an epigenome-wide association study meta-analysis

Background: Prenatal caffeine exposure may influence offspring health via DNA methylation, but no large studies have tested this. Materials & methods: Epigenome-wide association studies and differentially methylated regions in cord blood (450k or EPIC Illumina arrays) were meta-analyzed across six European cohorts (n = 3725). Differential methylation related to self-reported caffeine intake (mg/day) from coffee, tea and cola was compared with assess whether caffeine is driving effects. Results: One CpG site (cg19370043, PRRX1) was associated with caffeine and another (cg14591243, STAG1) with cola intake. A total of 12-22 differentially methylated regions were detected with limited overlap across caffeinated beverages. Conclusion: We found little evidence to support an intrauterine effect of caffeine on offspring DNA methylation. Statistical power limitations may have impacted our findings.

Genome-Wide Association Studies of Coffee Intake in UK/US Participants of European Ancestry Uncover Gene-Cohort Influences

Coffee is one of the most widely consumed beverages. We performed a genome-wide association study (GWAS) of coffee intake in US-based 23andMe participants (N=130,153) and identified 7 significant loci, with many replicating in three multi-ancestral cohorts. We examined genetic correlations and performed a phenome-wide association study across thousands of biomarkers and health and lifestyle traits, then compared our results to the largest available GWAS of coffee intake from UK Biobank (UKB; N=334,659). The results of these two GWAS were highly discrepant. We observed positive genetic correlations between coffee intake and psychiatric illnesses, pain, and gastrointestinal traits in 23andMe that were absent or negative in UKB. Genetic correlations with cognition were negative in 23andMe but positive in UKB. The only consistent observations were positive genetic correlations with substance use and obesity. Our study shows that GWAS in different cohorts could capture cultural differences in the relationship between behavior and genetics.

Associations between health behaviours, fertility and reproductive outcomes: triangulation of evidence in the Norwegian Mother, Father and Child Cohort Study (MoBa)

BACKGROUND

Guidance to improve fertility includes reducing alcohol and caffeine consumption, achieving healthy weight-range and stopping smoking. Advice is informed by observational evidence, which is often biased by confounding.

METHODS

This study primarily used data from a pregnancy cohort, the Norwegian Mother, Father and Child Cohort Study. First, we conducted multivariable regression of health behaviours (alcohol and caffeine consumption, body-mass index (BMI), and smoking) on fertility outcomes (e.g. time to conception) and reproductive outcomes (e.g. age at first birth) (n = 84,075 females, 68,002 males), adjusting for birth year, education and attention-deficit and hyperactive-impulsive (ADHD) traits. Second, we used individual-level Mendelian randomisation (MR) to explore possible causal effects of health behaviours on fertility/reproductive outcomes (n = 63,376 females, 45,460 males). Finally, we performed summary-level MR for available outcomes in UK Biobank (n = 91,462-1,232,091) and controlled for education and ADHD liability using multivariable MR.

RESULTS

In multivariable regression analyses, higher BMI associated with fertility (longer time to conception, increased odds of infertility treatment and miscarriage), and smoking was associated with longer time to conception. In individual-level MR analyses, there was strong evidence for effects of smoking initiation and higher BMI on younger age at first birth, of higher BMI on increased time to conception, and weak evidence for effects of smoking initiation on increased time to conception. Age at first birth associations were replicated in summary-level MR analysis; however, effects attenuated using multivariable MR.

CONCLUSIONS

Smoking behaviour and BMI showed the most consistent associations for increased time to conception and a younger age at first birth. Given that age at first birth and time to conception are positively correlated, this suggests that the mechanisms for reproductive outcomes are distinct to the mechanisms acting on fertility outcomes. Multivariable MR suggested that effects on age at first birth might be explained by underlying liability to ADHD and education.

Trends of caffeine intake from food and beverage among Chinese adults: 2004-2018

Caffeine is a kind of psychostimulant that naturally exist in foods. The benefits and risks of caffeine depend on the dose. Moreover, the intake of caffeine from dietary sources in China has seldom been assessed. We calculated the dietary caffeine intake of Chinese adult consumers from 2004 to 2018 and analyzed its consumption trends by using data from the China Health and Nutrition Survey and the National Food and Beverage Consumption Survey. Caffeine contents in different dietary items were determined by HPLC. Monte Carlo simulations were applied to estimate caffeine intake. Mann-Kendall trend test and linear regression were used to analyze the trend of caffeine consumption. Among 79,173 individuals, 3972 (5%) of the adult Chinese population consumed caffeine between 2004 and 2018. The average caffeine intake was 123 mg/day for male consumers and 116 mg/day for female consumers. The median and P75 caffeine intake raised over the 14 years. Traditional tea leaves, coffee and sodas are the main sources of caffeine intake. Our findings indicate that most Chinese adults consumed caffeine within the safe level (400 mg/day), but the caffeine consumption has shown an increasing trend in recent 14 years.

Possible role of caffeine in nicotine use onset among early adolescents: Evidence from the Young Mountaineer Health Study Cohort

BACKGROUND

Preventing nicotine use onset among children and youth is an important public health goal. One possible contributor that has received little empirical investigation is caffeine use. The goal of this study was to examine the possible contribution of caffeine to nicotine onset during early adolescence.

METHODS

We used data from the Young Mountaineer Health Study Cohort. Survey data were collected from 1,349 (response rate: 80.7%) 6th grade students (mean age at baseline 11.5 years) in 20 middle schools in West Virginia during the fall of 2020 and spring of 2021. We limited our analyses to students reporting never having used any form of nicotine at baseline. Logistic regression was employed in analyses.

RESULTS

Approximately 8% of participants reported having used nicotine at least once between baseline and the follow-up, and 4.7% reported solely using electronic nicotine delivery systems (ENDS) and no other forms of nicotine. In multivariable analyses, we controlled for many environmental, social, and behavioral variables known to influence nicotine use such as alcohol use, peer substance use, and perceived access to nicotine. We formulated our main independent variable, caffeine consumption, as continuous deciles. Any nicotine use, as well as ENDS use only at follow-up, were modeled as dependent variables. Caffeine was significantly associated with nicotine use in both models with ORs of 1.15 (1.04-1.27) and 1.13 (1.00-1.28).

CONCLUSIONS

Caffeine consumption among 6th grade non-nicotine users was associated with nicotine use at approximately 6-months follow-up.

Prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among active duty United States military personnel

BACKGROUND

Although representative data on caffeine intake in Americans are available, these data do not include US service members (SMs). The few previous investigations in military personnel largely involve convenience samples. This cross-sectional study examined prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among United States active duty military service members (SMs).

METHODS

A stratified random sample of SMs were asked to complete an on-line questionnaire on their personal characteristics and consumption of caffeinated products (exclusive of dietary supplements). Eighteen percent (n = 26,680) of successfully contacted SMs (n = 146,365) completed the questionnaire.

RESULTS

Overall, 87% reported consuming caffeinated products ≥1 time/week. Mean ± standard error per-capita consumption (all participants) was 218 ± 2 and 167 ± 3 mg/day for men and women, respectively. Caffeine consumers ingested 243 ± 2 mg/day (251 ± 2 mg/day men, 195 ± 3 mg/day women). On a body-weight basis, men and women consumed respectively similar caffeine amounts (2.93 vs 2.85 mg/day/kg; p = 0.12). Among individual caffeinated products, coffee had the highest use (68%), followed by sodas (42%), teas (29%), energy drinks (29%) and gums/candy/medications (4%). In multivariable logistic regression, characteristics independently associated with caffeine use (≥1 time/week) included female gender, older age, white race/ethnicity, higher body mass index, tobacco use or former use, greater alcohol intake, and higher enlisted or officer rank.

CONCLUSION

Compared to National Health and Nutrition Examination Survey data, daily caffeine consumption (mg/day) by SMs was higher, perhaps reflecting higher mental and physical occupational demands on SMs.

Knowledge, Consumption Pattern, and Adverse Effects of Energy Drinks among Asian Population: A Cross-Sectional Analysis from Malaysia

Background

The frequent expansion of the energy drinks (EDs) market has caused an extensive increase in the consumption of EDs, especially among younger populations. However, the lack of knowledge on EDs and their perceived beneficial effects could lead to excessive EDs consumption, which is strongly associated with serious side effects. This study aimed to assess the knowledge and perceived beneficial effects of EDs consumers and determine the consumption patterns and side effects experienced by different EDs consumers among the Malaysian population.

Methods

A descriptive cross-sectional study was conducted in Malaysia from February to April 2021. A structured and validated questionnaire, consisting of 5 sections with 46 items, was distributed online. Only 515 out of 591 invited participants agreed to participate in the study. Descriptive and inferential analysis were done using SPSS.

Results

The median age of participants was 23 ± 7.3 years. The majority of participants (65%) were unaware of the active ingredients of EDs, and approximately 40% of them had no idea that EDs contain caffeine. The main reason for consuming EDs was to stay awake (43%), and Red Bull was the most preferred brand (57%). Lack of rest (57%), headache (53%), and nervousness (49%) were the most experienced side effects. A significant difference was observed between consumption patterns and knowledge and perceived beneficial effects (p < 0.05). Our data showed a significant association between respondents' demographic data (e.g., coffee intake, smoking, and alcohol status) and their consumption pattern.

Conclusion

ED consumers in Malaysia were found to have limited knowledge on EDs. Therefore, attention should be drawn to the Ministry of Health regarding the significant side effects such as palpitation and nervousness experienced by ED consumers. Hence, awareness ought to be raised by adopting regulations or policies to regulate the sales and warning labels of EDs in Malaysia.

Caffeine Intake and Its Sex-Specific Association with General Anxiety: A Cross-Sectional Analysis among General Population Adults

(1) Background: Caffeine is one of the most consumed psychoactive stimulants worldwide. It has been suggested that caffeine intake at large doses can induce anxiety, whereas evidence of the role of low to moderate caffeine intake is scarce and inconsistent. Therefore, we aimed to assess the association between caffeine intake and general anxiety in adults recruited from the general population. (2) Methods: Participants from the French NutriNet-Santé web cohort with data on caffeine intake and general anxiety (assessed during 2013−2016 through the trait subscale of Spielberger’s State-Trait Anxiety Inventory Form Y; STAI-T, sex-specific top quartile = high trait anxiety) were included in this cross-sectional analysis (n = 24,197; 74.1% women; mean age = 53.7 ± 13.9 years). Mean dietary intake was estimated using ≥2 self-reported 24-h dietary records. Sex-specific tertiles of caffeine intake and low/high trait anxiety were calculated. Multivariable logistic regression models were fitted to assess the odds ratio (OR) and 95% confidence interval (CI) for the association between caffeine intake and general anxiety by sex. (3) Results: In the total sample, the mean caffeine intake (mg/day) from all dietary sources combined was 220.6 ± 165.0 (women = 212.4 ± 159.6; men = 243.8 ± 177.7, p < 0.01). Women in the highest tertile of caffeine intake showed significantly higher odds for high trait anxiety compared to those in the lowest tertile (reference), even after adjustment for potential confounders (OR: 1.13; 95% CI: 1.03−1.23). No significant associations were detected among men. Sensitivity analyses according to perceived stress level and sugar intake, respectively, showed similar results. (4) Conclusions: The results suggest that higher caffeine intake is associated with higher odds of general anxiety among women but not among men. Further research is needed to confirm the sex-specific findings and elucidate the potential causal relationship between caffeine intake and anxiety status.

Heritability of tea drinking and its relationship with cigarette smoking in the Chinese male adult twins

The aims of this study are to estimate the contributions of genetic factors to the variation of tea drinking and cigarette smoking, to examine the roles of genetic factors in their correlation and further to investigate underlying causation between them. We included 11 625 male twin pairs from the Chinese National Twin Registry (CNTR). Bivariate genetic modelling was fitted to explore the genetic influences on tea drinking, cigarette smoking and their correlation. Inference about Causation through Examination of FAmiliaL CONfounding (ICE FALCON) was further used to explore the causal relationship between them. We found that genetic factors explained 17% and 23% of the variation in tea drinking and cigarette smoking, respectively. A low phenotypic association between them was reported (r_ph  = 0.21, 95% confidence interval [CI]: [0.19, 0.24]), which was partly attributed to common genetic factors (r_A  = 0.45, 95% CI [0.19, 1.00]). In the ICE FALCON analysis with current smoking as the exposure, tea drinking was associated with his own (βself = 0.39, 95% CI [0.23, 0.55]) and his co-twin's smoking status (βco-twin = 0.25, 95% CI [0.10, 0.41]). Their association attenuated with borderline significance conditioning on his own smoking status (p = 0.045), indicating a suggestive causal effect of smoking status on tea drinking. On the contrary, when we used tea drinking as the predictor, we found familial confounding between them only. In conclusion, both tea drinking and cigarette smoking were influenced by genetic factors, and their correlation was partly explained by common genetic factors. In addition, our finding suggests that familial confounders account for the relationship between tea drinking and cigarette smoking. And current smoking might have a causal effect on weekly tea drinking, but not vice versa.

At the Origins of Tobacco-Smoking and Tea Consumption in a Virgin Population (Yakutia, 1650–1900 A.D.): Comparison of Pharmacological, Histological, Economic and Cultural Data

(1) Background: The way tobacco and tea spread among virgin populations is of major interest our understanding of how ancient economic and cultural practices could have influenced current habits. (2) Methods: hair concentrations of theobromine, theophylline, caffeine, nicotine, and cotinine were measured in hair samples from 47 frozen bodies of people from eastern Siberia, dated from the contact with Europeans to the assimilation of people into Russian society. (3) Results: hair concentration of theobromine, theophylline, and caffeine vary with the type of beverage consumed: green, black, or local herbal teas. Shortly after the first contacts, a few heavy consumers of tobacco were found among light or passive consumers. Tobacco-related co-morbidities began to be recorded one century after and heavy tea users were only found from the 19th century (4) Conclusions: Economic factors and social and family contacts seem to have played a decisive role in tobacco consumption very early on. Behavioral evolution governed the process of substance integration into Siberian culture and was a determinant for the continuity of its use across long periods of time. Analyzing the respective contributions of social and economic processes in the use of these substances opens avenues of investigation for today’s public health.

Maternal and child genetic liability for smoking and caffeine consumption and child mental health: an intergenerational genetic risk score analysis in the ALSPAC cohort

BACKGROUND AND AIMS

Previous studies suggest an association between maternal tobacco and caffeine consumption during and outside of pregnancy and offspring mental health. We aimed to separate effects of the maternal environment (intrauterine or postnatal) from pleiotropic genetic effects.

DESIGN

Secondary analysis of a longitudinal study. We (i) validated smoking and caffeine genetic risk scores (GRS) derived from published genome-wide association study (GWAS) for use during pregnancy, (ii) compared estimated effects of maternal and offspring GRS on childhood mental health outcomes and (iii) tested associations between maternal and offspring GRS on their respective outcomes.

SETTING

We used data from a longitudinal birth cohort study from England, the Avon Longitudinal Study of Parents and Children (ALSPAC).

PARTICIPANTS

Our sample included 7921 mothers and 7964 offspring.

MEASUREMENTS

Mental health and non-mental health phenotypes were derived from questionnaires and clinical assessments: 79 maternal phenotypes assessed during and outside of pregnancy and 71 offspring phenotypes assessed in childhood (<10 years) and adolescence (11-18 years).

FINDINGS

The maternal smoking and caffeine GRS were associated with maternal smoking and caffeine consumption during pregnancy (2nd trimester: Psmoking  = 3.0 × 10-7 , Pcaffeine  = 3.28 × 10-5 ). Both the maternal and offspring smoking GRS showed evidence of association with reduced childhood anxiety symptoms (βmaternal  = -0.033; βoffspring  = -0.031) and increased conduct disorder symptoms (βmaternal  = 0.024; βoffspring  = 0.030), after correcting for multiple testing. Finally, the maternal and offspring smoking GRS were associated with phenotypes related to sensation seeking behaviours in mothers and adolescence (e.g. increased symptoms of externalising disorders, extraversion and monotony avoidance). The caffeine GRS showed weaker evidence for associations with mental health outcomes.

CONCLUSIONS

We did not find strong evidence that maternal smoking and caffeine genetic risk scores have a causal effect on offspring mental health outcomes. Our results confirm that the smoking genetic risk scores also captures liability for sensation seeking personality traits.

The association between coffee consumption and periodontitis: a cross-sectional study of a northern German population

BACKGROUND

Positive and negative influences on oral health are attributed to coffee consumption. The aim of the current study is to evaluate the association between coffee consumption and periodontitis in the general population of Hamburg.

METHODS

A total of 6,209 participants from the Hamburg City Health Study were included in this cross-sectional study. Information on coffee consumption was collected using a food frequency questionnaire. Periodontal examination included assessment of dental care ability via Plaque Index, measurement of pocket depth, gingival recession, and bleeding on probing. Classification was based on the criteria of Eke and Page. Ordinal logistic regression models were performed unadjusted and adjusted for confounding variables.

RESULTS

Periodontal cohort consists of 6,209 participants, presenting either none/mild (n = 1,453, 39.6% men, 2.4% strong coffee drinkers), moderate (n = 3,580, 49.3% men, 3.3% strong coffee drinkers), or severe (n = 1,176, 60.9% men, 5.0% strong coffee drinkers) periodontitis. There was a significant association between strong coffee consumption (≥ 7or more cups/day) and periodontitis (OR: 1.51; CI: 1.07, 2.12; p > 0.001), compared with low coffee consumption. Conversely, moderate coffee consumption was not associated with periodontitis, compared with low coffee consumption.

CONCLUSION

and clinical relevance. In this cross-sectional study of a northern German population, strong coffee consumption was significantly associated with periodontitis. Influence of changes in coffee consumption on periodontal disease etiology/progression should be investigated in future prospective study designs, in order to identify strong coffee consumption as a potential risk factor of periodontitis.

Coffee consumption and the risk of cerebrovascular disease: a meta-analysis of prospective cohort studies

Background

Stroke is a crucial health threat to adults worldwide. Despite extensive knowledge of risk-factor mitigation, no primary prevention exists for healthy people. Coffee is a widely consumed beverage globally. Health benefit of coffee for several neurological diseases has been identified; however, the association between stroke risk and coffee consumption in healthy people has not been determined. We investigated the effect of coffee on stroke risk by conducting a meta-analysis of prospective cohort studies.

Methods

Electronic databases, namely PubMed, BioMed Central, Medline, and Google Scholar, were searched using terms related to stroke and coffee. Articles that described clear diagnostic criteria for stroke and details on coffee consumption were included. The reference lists of relevant articles were reviewed to identify eligible studies not shortlisted using these terms. Enrolled studies were grouped into three outcome categories: overall stroke, hemorrhagic stroke, and ischemic stroke.

Results

Seven studies were included and all of them were large-scale, long-term, follow-up cohort studies of a healthy population. Upon comparing the least-coffee-consuming groups from each study, the meta-analysis revealed a reduction in the risk of overall stroke during follow-up (hazard ratio [HR] for overall stroke = 0.922, 95% confidence interval [CI] = 0.855–0.994, P = 0.035). In studies with a clear definition of hemorrhagic and ischemic stroke, coffee consumption reduced the risk of ischemic stroke more robustly than that of hemorrhagic stroke (hemorrhagic, HR = 0.895, 95% CI = 0.824–0.972, P = .008; ischemic, HR = 0.834, 95% CI = 0.739–0.876, P < .001). No obvious dose-dependent or U-shaped effect was observed.

Conclusions

Coffee consumption reduces the risk of overall stroke, especially ischemic stroke. Further investigation is required to identify beneficial components in coffee, including caffeine and phenolic acids, to develop preventive medication for stroke.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02411-5.

Coffee consumption and risk of type 2 diabetes mellitus in Asians: A meta-epidemiological study of population-based cohort studies

BACKGROUND

Previous systematic reviews have consistently reported that coffee consumption has a preventive effect on the occurrence of type 2 diabetes mellitus (T2DM). However, further evaluations between coffee consumption and the risk of T2DM in Asian populations are needed.

AIM

To conduct a meta-epidemiological study on systematic reviews evaluating the association between coffee consumption and the risk of T2DM in Asian people.

METHODS

The selection criterion was defined as a population-based prospective cohort study evaluating the association between coffee consumption and the risk of T2DM in Asian populations, reporting the adjusted relative risk (RR) and its 95% confidence interval (CI) for potential confounders. A fixed-effect model meta-analysis was applied to calculate the summary RR and its 95%CI in less than 50% of the I² value indicating the level of heterogeneity. A two-stage fixed-effects dose-response meta-analysis (DRMA) was performed to calculate the risk per unit dose (a cup per day).

RESULTS

A total of seven studies were selected in this meta-epidemiological study. The risk of T2DM in Asian populations was significantly reduced in the highest to the lowest dose group (summary RR = 0.73, 95%CI: 0.66-0.82; I² value = 0.0%). The DRMA showed that drinking one cup of coffee per day reduced the risk of T2DM in Asian populations by 8% (RR = 0.92, 95%CI: 0.90-0.95).

CONCLUSION

These findings support the conclusion that coffee consumption has a protective effect on the occurrence of T2DM in Asian men and women.

Associations of coffee and tea consumption with lung cancer risk

Associations of coffee and tea consumption with lung cancer risk have been inconsistent, and most lung cancer cases investigated were smokers. Included in this study were over 1.1 million participants from 17 prospective cohorts. Cox regression analyses were conducted to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Potential effect modifications by sex, smoking, race, cancer subtype and coffee type were assessed. After a median 8.6 years of follow-up, 20 280 incident lung cancer cases were identified. Compared with noncoffee and nontea consumption, HRs (95% CIs) associated with exclusive coffee drinkers (≥2 cups/d) among current, former and never smokers were 1.30 (1.15-1.47), 1.49 (1.27-1.74) and 1.35 (1.15-1.58), respectively. Corresponding HRs for exclusive tea drinkers (≥2 cups/d) were 1.16 (1.02-1.32), 1.10 (0.92-1.32) and 1.37 (1.17-1.61). In general, the coffee and tea associations did not differ significantly by sex, race or histologic subtype. Our findings suggest that higher consumption of coffee or tea is associated with increased lung cancer risk. However, these findings should not be assumed to be causal because of the likelihood of residual confounding by smoking, including passive smoking, and change of coffee and tea consumption after study enrolment.

Effects of Oral pH Changes on Smoking Desire

BACKGROUND

Nicotine addiction is associated with nicotine absorption from the buccal mucosa, and it is stated that the main factor that determines nicotine absorption is saliva pH. In the literature, the effects of changes in saliva pH values after eating and drinking on smoking desire in smokers were not questioned.

AIM

To show the effect of saliva pH changes on smoking desire. The secondary aim was to show the impact of coffee and water drinking on saliva pH and smoking on oral-dental health (oral hygiene and gingival bleeding).

STUDY DESIGN

Case-control study.

METHODS

A questionnaire was administered that included "Sociodemographic Data Form" and smoking history and Fagerström Test for Nicotine Dependence (FTND). Oral and dental examinations were performed with mirror sonds and using oral hygiene standard Silness and Leöe plaque index and DMFT Index (Index of Decayed Missing or Filled Teeth). Untreated saliva samples were taken, and baseline saliva flow rate and pH values were measured. To assess pH changes, saliva pH was remeasured after sugar-free instant coffee and water consumption. Smoking desire was evaluated with the Visual Analog Scale (VAS).

RESULTS

In this study, 24 (55.8%) females and 19 (44.2%) males were among the 43 smoking and 39 nonsmoking cases. Smoking was significantly associated with poor oral hygiene (in smokers 4.71 (±1.40), in non-smokers 2.30 (±1.59); P < .01). DMFT index was higher in smokers than in non-smokers (in smokers 6.45 (±3.69), in non-smokers 3.87 (±2.67); P < .01). Gingival bleeding was more prevalent in smokers (0.68 (±0.76)) than non-smokers (1.20 (±0.90); P = .009). Salivary flow rates were lower in smokers (in smokers 2.56 (±1.34), in non-smokers 3.00 (±1.22), P = .06). In both groups, pH values increased after coffee consumption and decreased after water; in smokers basal: 6.67 (±0.41), pH coffee: 6.93 (±0.36), pH water: 6.85 (±0.33); in non-smokers pH basal: 6.84 (±0.37), pH coffee: 7.02 (±0.37), pH water: 6.97 (±0.31), P < .01. The VAS values of smokers at basal 4.73 (±3.21); P < 0.01, after coffee consumption 4.91 (±3.08); P < .01, and after water 3.15 (±2.72); P < .01.

CONCLUSION

The saliva pH increased after coffee consumption and decreased after drinking water. Besides, VAS values decreased significantly after drinking water. The results suggest that a simple behavior such as drinking water may be used in conjunction with behavioral and cognitive therapies to pursue smoking cessation.

Does Prenatal Exposure to CNS Stimulants Increase the Risk of Cardiovascular Disease in Adult Offspring?

Prenatal exposure to an adverse uterine environment can have long lasting effects on adult offspring through DNA methylation, histone acetylation, and other epigenetic effects that alter gene expression and physiology. It is well-known that consumption of CNS stimulants such as caffeine, nicotine, amphetamines, and cocaine during pregnancy can adversely impact the offspring. However, most work in this area has focused on neurological and behavioral outcomes and has been limited to assessments in young offspring. The impact of prenatal exposure to these agents on the adult cardiovascular system has received relatively little attention. Evidence from both animal and human studies indicate that exposure to CNS stimulants during the gestational period can negatively impact the adult heart and vasculature, potentially leading to cardiovascular diseases later in life. This review discusses our current understanding of the impact of prenatal exposure to cocaine, methamphetamine, nicotine, and caffeine on the adult cardiovascular system.

Association between self-reported caffeine intake during pregnancy and social responsiveness scores in childhood: The EARLI and HOME studies

Maternal nutrition during gestation has been investigated for its role in child neurodevelopment. However, little is known about the potential impact of gestational caffeine exposure on child autistic behaviors. Here, we assess the relation between maternal caffeine intake during pregnancy and children's behavioral traits related to Autism Spectrum Disorder (ASD). We harmonized data from two pregnancy cohorts, Early Autism Risk Longitudinal Investigation (EARLI) (n = 120), an enriched-risk cohort of mothers who previously had a child with ASD, from Pennsylvania, Maryland, and Northern California (2009-2012), and the Health Outcomes and Measures of the Environment (HOME) Study (n = 269), a general population cohort from Cincinnati, Ohio (2003-2006). Mothers self-reported caffeine intake twice during pregnancy. Caregivers reported child behavioral traits related to ASD using the Social Responsiveness Scale (SRS) when children were aged 3-8 years. Higher scores indicate more ASD-related behaviors. We estimated covariate-adjusted differences in continuous SRS T-scores per interquartile range increase in caffeine intake. Self-reported caffeine intake during pregnancy was positively associated with SRS T-scores among children in EARLI (β: 2.0; 95% CI -0.1, 4.0), but to a lesser extent in HOME (β: 0.6; 95% CI -0.5, 1.6). In HOME, pre-pregnancy body mass index (BMI) modified the association between caffeine intake and SRS T-scores, where more positive associations were observed among women with higher BMIs. Our findings suggest gestational caffeine intake may represent a marker of vulnerability to childhood ASD-related behaviors. Additional studies are warranted to extend these findings.

Revealing oral microbiota composition and functionality associated with heavy cigarette smoking

BACKGROUND

Heavy tobacco smoking, a hallmark feature of lung cancer, is drastically predominant in Middle Eastern populations. The precise links between nicotine dependence and the functional contribution of the oral microbiota remain unknown in these populations.

METHODS

We evaluated the composition and functional capabilities of oral microbiota with relation to cigarette smoking in 105 adults through shotgun metagenomics using buccal swabs.

RESULTS

The oral microbiota composition in our study subjects was dominated by the phyla Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes, in addition to the genera Prevotella and Veillonella, similar to previously described westernized cohorts. Furthermore, the smoker's oral microbiota represented a significant abundance of Veillonella dispar, Leptotrichia spp. and Prevotella pleuritidis when compared to non-smokers. Within the smoking groups, differential relative abundance testing unveiled relative abundance of Streptobacillus hongkongensis, Fusobacterium massiliense, Prevotella bivia in high nicotine dependent compared to low nicotine dependent profiles based on Fagerström Test for Nicotine Dependence. Functional profiling showed marked differences between smokers and non-smokers. Smokers exhibited an enrichment of Tricarballylate utilization and Lactate racemization when compared to the non-smokers. According to their nicotine dependence, enrichment of Xanthosine utilization, p-Aminobenzoyl-Glutamate utilization, and multidrug efflux pump in Campylobacter jejuni biosynthesis modules were detected in the high nicotine dependent group.

CONCLUSIONS

These compositional and functional differences may provide critical insight on how variations in the oral microbiota could predispose to respiratory illnesses and smoke cessation relapse in cigarette smokers. In particular, the observed enrichment of Fusobacterium and Prevotella in the oral microbiota possibly suggests an intriguing linkage to gut and lung cancers.

Estimates of Caffeine Use Disorder, Caffeine Withdrawal, Harm and Help-seeking in New Zealand: A cross-sectional survey

BACKGROUND

Caffeine Use Disorder (CUD) is not yet formally recognized in the DSM-5, but emerging evidence suggests CUD could impact up to one in five people. The primary aim of this study was to estimate levels of caffeine consumption and its associations with CUD and withdrawal, taking socio-demographic characteristics (age, gender, ethnicity, income) into account. Secondary aims were to measure caffeine-related harm and treatment preferences.

METHODS

We administered an online cross-sectional survey via Facebook to a convenience sample of 2379 adults in New Zealand. Caffeine consumption was assessed across six products: coffee, tea, energy drinks, cola, alcohol mixed with caffeine, and other products (e.g., caffeine pills, sports supplements).

RESULTS

20% of participants met proposed criteria for CUD, with 30% meeting DSM-5 criteria for caffeine withdrawal. Moderate (200-400 mg per day) and high consumption (>400 mg per day) was associated with a three-fold increase in the odds of CUD and a two-fold increase in the odds of withdrawal. Women and current smokers were at higher risk of CUD and withdrawal even at moderate consumption levels. Nearly 85% of respondents experienced at least one caffeine-related harm in the past 12-months. The number of harms increased with level of caffeine consumption. Nearly 50% indicated a self-help treatment for caffeine reduction would be of interest.

CONCLUSIONS

High rates of CUD and caffeine withdrawal amongst moderate caffeine users, women and smokers suggests caffeine consumption guidelines may need refinement. Caffeine-related harm that is not clinically meaningful may still be of concern to individuals and warrants further investigation.

Alcohol, nicotine, and caffeine consumption on a public U.S. university campus determined by wastewater-based epidemiology

Alcohol, nicotine, and caffeine use in at-risk populations is a public health concern that claims over 550,000 lives annually. Self-reported surveys from college students often reveal overconsumption of these substances. Unfortunately, the costs of these surveys are high, and consequently, the results from few studies are often extrapolated across the entire target population. Here we employed wastewater-based epidemiology (WBE) to directly measure the levels of these three psychotropic substances and their metabolites in sewage from a large public Southwestern U.S. university campus during the 2017-2018 academic year. Results showed per person alcohol consumption was 11.3 ± 7.5 g d^-1 person^-1 or 0.8 ± 0.5 drinks d^-1 person^-1, similar to averages of nationwide estimates from self-reporting of this subpopulation aged 18-25 years (10.1 ± 0.8 g d^-1 person^-1 or 0.7 ± 0.06 drinks d^-1 person^-1). Caffeine and nicotine consumption determined by WBE were significantly lower (p < 0.05) than nationwide estimates from self-reporting (caffeine: 114 ± 49 vs. 178 ± 19 mg d^-1 person^-1; nicotine: 627 ± 219 vs. 927 ± 243 μg d^-1 person^-1). Strong positive correlations were found for consumption of alcohol and nicotine (Spearman r_s: 0.71; p < 0.01), and nicotine and caffeine (0.59, p < 0.01), but not alcohol and caffeine (0.17). Alcohol and nicotine consumption were significantly higher on weekends compared to weekdays (p < 0.01), while caffeine consumption was higher during the week (p < 0.05). This first U.S. WBE study on alcohol, nicotine, and caffeine use among U.S. college students demonstrated the feasibility and practicality of longitudinally tracking the behavior of an entire campus population of 60,000 students directly, repeatedly, and more inexpensively (US$0.58/person) compared to conventional questionnaires (US$127/person).

Mechanisms for the reduction of caffeine consumption: What, how and why

BACKGROUND

Anecdotal evidence suggests consumers of caffeine self-administer strategies to reduce consumption, but little is known of what these strategies are or how they are implemented. This study aimed to understand the lived experience of reducing caffeine consumption including specific techniques (what) and implementation strategies (how), harm and withdrawal symptoms (why).

METHODS

We developed a classification system through an inductive and deductive approach and applied it to a large dataset derived from online sources.

RESULTS

A total of 112 internet sources were identified, containing 2,682 different strategies. The classification system identified 22 categories of Behaviour Change Techniques (BCT): 10 categories were directly aligned with a BCT, one was split into two categories (substance and behavioural substitution), six represented a cluster of BCT's (e.g., withdrawal management and maintaining momentum) and four appeared to uniquely represent a consumer perspective (e.g., realisation of a problem). The most common techniques were substance substitution, seek knowledge and information, avoidance of caffeine and identify prompts for change. The most frequently perceived benefit was the stimulating effects of caffeine and a feeling of mental alertness. The most frequently cited harms were sleep problems including insomnia and concerns about dependence (or addiction) to caffeine. We found 16 categories of withdrawal symptoms. The most frequently endorsed symptom was headaches, followed by fatigue, exhaustion and low energy.

CONCLUSIONS

Consumers use a wide range of techniques when attempting to reduce caffeine consumption. Treatment approaches are focused on fading, but the current study found consumers most frequently focus on substance and behavioural substitution.

Coffee and cigarettes: Examining the association between caffeinated beverage consumption and smoking behaviour among youth in the COMPASS study

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Caffeinated beverage consumption is associated with smoking behaviours in youth.

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High energy drink consumption is most strongly associated with smoking behaviours.

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Caffeinated beverages and smoking behaviour demonstrate a dose–response association.

In adults, coffee, sugar-sweetened beverage (SSB) and high energy drink consumption have been related to increases in risky behaviour, including smoking. However, these associations are not well understood during adolescence. The purpose of this study was to examine the association between beverage consumption and smoking behaviour among Canadian adolescents. Using data from the COMPASS study (2016–2017; n = 46,957), four models were developed to investigate whether beverage consumption explained variability in smoking behaviour in adolescence (age = 15.7 ± 1.2 yrs); 1) smoking status; 2) e-cigarette use status; 3) days smoking cigarettes per month; and 4) days using an e-cigarette per month. Models were adjusted for demographic factors. Logistic (models 1 and 2) and ordinal logistic (models 3 and 4) were used for analysis. An association between the frequency of SSBs, coffee/tea or high energy drinks consumption and smoking behaviour was identified in all models. Greater beverage consumption was associated with being a current smoker (OR = 2.46 (2.02, 2.99)), former smoker, (OR = 2.50 (1.53, 4.08)), and currently using an e-cigarette (OR = 4.66 (3.40, 6.40)). Higher beverage consumption was also associated with more days smoking/using an e-cigarette per month (OR = 2.67 (1.92, 3.70) and 3.45 (2.32, 5.12), respectively). High energy drink consumption on 4 or 5 days of the school week was the best predictor of smoking behaviour in all models. Given the health consequences of smoking and e-cigarette use and their association with SSB, high energy drinks and coffee consumption, policy initiatives to prevent smoking initiation and limit access to these beverages needs ongoing attention and implementation.

Coffee consumption and risk of colorectal cancer in the Cancer Prevention Study-II Nutrition Cohort

BACKGROUND

The association between coffee consumption and colorectal cancer risk generally appears null, but recent evidence suggests that risk may vary by coffee type. We examined associations of caffeinated and decaffeinated coffee intake with colorectal cancer risk overall and with colon and rectum separately, among older U.S. men and women.

METHODS

In 1999, 47,010 men and 60,051 women with no previous diagnosis of cancer, aged 47-96 years, in the Cancer Prevention Study-II Nutrition Cohort completed a food frequency questionnaire that assessed caffeinated and decaffeinated coffee intake; consumption was updated in 2003. A total of 1829 colorectal cancer cases were verified through June 2015. Cox proportional hazards regression was used to estimate multivariable-adjusted hazard rate ratios (HRs) and 95% confidence intervals (CIs), adjusting for smoking history, alcohol, caffeinated/decaffeinated coffee intake (depending on the model), and other colorectal cancer risk factors.

RESULTS

Consumption of ≥2 cups/day of decaffeinated coffee, compared to no decaffeinated coffee, was associated with lower risk of overall colorectal cancer (HR = 0.82, 95% CI: 0.69-0.96, P-trend = 0.04), colon cancer (HR = 0.82, 95% CI: 0.69-0.99, P-trend = 0.05) and rectal cancer (HR = 0.63, 95% CI: 0.40-0.99, P-trend = 0.17). Consumption of ≥2 cups/day of caffeinated coffee was associated with higher risk of rectal cancer (HR = 1.37, 95% CI: 0.99-1.89, P-trend = 0.04), but not with colorectal or colon cancer.

CONCLUSION

In this prospective study, higher intake of decaffeinated coffee was associated with lower risk of colorectal, colon, and rectal cancers. Further study on associations of caffeinated and decaffeinated coffee with colorectal cancer risk by subsite is needed.

Investigating the genetic and causal relationship between initiation or use of alcohol, caffeine, cannabis and nicotine

BACKGROUND

Caffeine, alcohol, nicotine and cannabis are commonly used psychoactive substances. While the use of these substances has been previously shown to be genetically correlated, causality between these substance use traits remains unclear. We aimed to revisit the genetic relationships among different measures of SU using genome-wide association study (GWAS) summary statistics from the UK Biobank, International Cannabis Consortium, and GWAS & Sequencing Consortium of Alcohol and Nicotine use.

METHODS

We obtained GWAS summary statistics from the aforementioned consortia for ten substance use traits including various measures of alcohol consumption, caffeine consumption, cannabis initiation and smoking behaviours. We then conducted SNP-heritability (h²) estimation for individual SU traits, followed by genetic correlation analyses and two-sample Mendelian randomisation (MR) studies between substance use trait pairs.

RESULTS

SNP h² of the ten traits ranged from 0.03 to 0.11. After multiple testing correction, 29 of the 45 trait pairs showed evidence of being genetically correlated. MR analyses revealed that most SU traits were not causally associated with each other. However, we found evidence for an MR association between regular smoking initiation and caffeine consumption 40.17 mg; 95 % CI: [24.01, 56.33] increase in caffeine intake per doubling of odds in smoking initiation). Our findings were robust against horizontal pleiotropy, SNP-outliers, and the direction of causality was consistent in all MR analyses.

CONCLUSIONS

Most of the substance traits were genetically correlated but there is little evidence to establish causality apart from the relationship between smoking initiation and caffeine consumption.

The Joint Effects of Some Beverages Intake and Smoking on Chronic Obstructive Pulmonary Disease in Korean Adults: Data Analysis of the Korea National Health and Nutrition Examination Survey (KNHANES), 2008-2015

Some beverages and smoking cause an inflammatory response in the lungs and airways in a similar way, ultimately affecting chronic obstructive pulmonary disease (COPD) occurrence. Using a nationally representative health survey database, this study investigates the individual and joint effects of consumption of different beverages and smoking on COPD. This study is a cross-sectional analysis of 15,961 Korean adults in the Korea National Health and Nutritional Examination Survey of 2008–2015. COPD was defined as forced expiratory volume in 1 s (FEV₁) divided by forced vital capacity (FVC) <0.70. We used multiple linear and logistic regression models to examine the association of beverage consumption and smoking with an FEV₁/FVC ratio and odds ratio (OR) for COPD. The mean FEV₁/FVC ratio decreased with increasing soda intake (p = 0.016), coffee intake (p = 0.031), and smoking status; however, the mean FEV₁/FVC ratio increased with increasing green tea intake frequency (p = 0.029). When soda intake increased to 10 times/month, the OR of having COPD increased to 1.04 times (95% CI: 1.01, 1.07). The positive joint effect of soda intake and smoking on COPD was marginally significant (p = 0.058). We found that soda intake, coffee intake, and smoking increased airflow limitation while green tea intake decreased it. In addition, soda intake and smoking had a positive joint effect on COPD in the Korean population.

Substance use: Interplay between polygenic risk and neighborhood environment

BACKGROUND

Tobacco, alcohol, and cannabis use are prevalent behaviors that pose considerable health risks. Genetic vulnerability and characteristics of the neighborhood of residence form important risk factors for substance use. Possibly, these factors do not act in isolation. This study tested the interaction between neighborhood characteristics and genetic risk (gene-environment interaction, GxE) and the association between these classes of risk factors (gene-environment correlation, rGE) in substance use.

METHODS

Two polygenic scores (PGS) each (based on different discovery datasets) were created for smoking initiation, cigarettes per day, and glasses of alcohol per week based on summary statistics of different genome-wide association studies (GWAS). For cannabis initiation one PGS was created. These PGS were used to predict their respective phenotype in a large population-based sample from the Netherlands Twin Register (N = 6,567). Neighborhood characteristics as retrieved from governmental registration systems were factor analyzed and resulting measures of socioeconomic status (SES) and metropolitanism were used as predictors.

RESULTS

There were (small) main effects of neighborhood characteristics and PGS on substance use. One of the 14 tested GxE effects was significant, such that the PGS was more strongly associated with alcohol use in individuals with high SES. This was effect was only significant for one out of two PGS. There were weak indications of rGE, mainly with age and cohort covariates.

CONCLUSION

We conclude that both genetic and neighborhood-level factors are predictors for substance use. More research is needed to establish the robustness of the findings on the interplay between these factors.

Effects of combined coffee and alcohol use over cigarette demand among treatment-seeking smokers

OBJECTIVE

This study is aimed at comparing the relative reinforcing efficacy (RRE) of nicotine though CPT performance in function of alcohol and coffee consumption of treatment-seeking smokers.

MATERIAL AND METHODS

A total of 88 treatment-seeking smokers (60.2 % female) completed the CPT. A multivariate analysis of variance (MANOVA) was used to compare alcohol (consumers and abstainers of alcohol) and coffee intake (high coffee consumers and low coffee consumers) on CPT indices.

RESULTS

Univariate effects of coffee × alcohol use interaction were significant for elasticity [F (1, 83) = 4.9435, p = .038, η2 = .051] and intensity [F (1, 83) = 6.972, p = .01, η2 = .077].

CONCLUSIONS

Alcohol and coffee use is associated with an elevated cigarette demand among treatment-seeking smokers. This finding suggests the need for specific interventions to reduce alcohol and coffee use in order to increase the effectiveness of treatments for smoking cessation.

Knowledge and consumption of caffeinated products by university students in Beirut, Lebanon

BACKGROUND & AIMS

Caffeine consumption is well studied among children and adults on a national level. Literature about university student comprehensive consumption, in particular, is scarce. This study aims to measure university student caffeine consumption during weekdays, weekends and exam days.

METHODS

A cross-sectional study using the online Lime Survey tool was sent to a random sample of 2154 students at the American University of Beirut. The survey included a self-report questionnaire that asked participants to quantify servings of various products consumed on a typical day using the visual presentation of available serving sizes of common brand names present in the market.

RESULTS

A total of 146 students replied to the survey, yielding a response rate of 6.8%. The mean total consumption of caffeine was 373.1 ± 286.6 mg during weekdays, 326.7 ± 305.3 mg on weekends and 473.6 ± 444.0 mg during exams. Consumption beyond the approved level of 400 mg/day was found among 34.9%, 28.8% and 46.6% of participants during weekdays, weekends and exams, respectively. Products other than coffee and energy drinks contributed to at least 61% of daily caffeine consumption. Total caffeine consumption was associated with smoking, alcohol drinking, and general stress level.

CONCLUSION

University students consume high levels of caffeine from products other than coffee and energy drinks. During exams, the total daily consumption of caffeine is alarmingly above the Food and Drug Administration (FDA)-approved daily intake. Targeted programs and awareness campaigns are needed on campus.

Dietary Research on Coffee: Improving Adjustment for Confounding

Meta-analyses have reported higher levels of coffee consumption to be associated with lower mortality. In contrast, some systematic reviews have linked coffee consumption to increased risks for lung cancer and hypertension. Given these inconsistencies, this narrative review critically evaluated the methods and analyses of cohort studies investigating coffee and mortality. A specific focus was adjustment for confounding related to smoking, healthy and unhealthy foods, and alcohol. Assessment of 36 cohort samples showed that many did not adequately adjust for smoking. Consuming 1-5 cups of coffee per day was related to lower mortality among never smokers, in studies that adjusted for pack-years of smoking, and in studies adjusting for healthy and unhealthy foods. Possible reduced health benefits for coffee with added sugar have not been adequately investigated. Research on coffee and health should report separate analyses for never smokers, adjust for consumption of healthy and unhealthy foods, and for sugar added to coffee.

Caffeine Consumption in Switzerland: Results from the First National Nutrition Survey MenuCH

Caffeine is a natural psychostimulant with a potentially positive impact on health when consumed in moderation and a negative impact at high dose (> 400 mg/day). So far, no study has examined self-reported caffeine consumption in Switzerland. Our objectives were to determine 1) the caffeine consumption per adult, 2) the main sources of caffeine intake in the Swiss diet, and 3) the timing of caffeine consumption during the day. We used data from the 2014-2015 national nutrition survey menuCH (adults aged 18 to 75 years old, n = 2057, weighted n = 4,627,878), consisting of two 24-hour dietary recalls. Caffeine content in consumed foods was systematically assessed using laboratory analyses in samples of Swiss caffeinated beverages, information from food composition databases, and estimations from standard recipes. Mean (± SD) daily caffeine consumption per person and percentile 95 were 191 mg/day (± 129) and 426 mg/day, respectively. We observed differences in mean caffeine consumption across age groups (18-34 y: 140 mg/day; 50-64 y: 228 mg/day), linguistic regions (German-speaking: 204 mg/day; French-speaking: 170 mg/day, Italian-speaking: 136 mg/day), and smoking status (never smokers: 171 mg/day; current smokers: 228 mg/day). The three main sources of caffeine intake were 1) coffee (83% of total caffeine intake), 2) tea (9%) and 3) soft drinks (4%). Caffeine consumption was highest between 06:00 and 09:00 (29%) and the circadian rhythm slightly differed across linguistic regions and age groups. The mean caffeine consumption in the Swiss adult population was similar to that reported in neighbouring countries.

Associations between tea and coffee beverage consumption and the risk of lung cancer in the Singaporean Chinese population

BACKGROUND

Tea and coffee are widely consumed beverages. Tea flavonoids have been shown to inhibit lung tumorigenesis using in vitro and in vivo models. Conversely, coffee contains complex mixtures of biochemically active compounds, some of which may have genotoxic and mutagenic properties. However, previous epidemiologic studies have shown inconsistent results on tea and coffee in relation to lung cancer risk.

METHODS

The Singapore Chinese Health Study is a population-based prospective cohort of 63,257 Singaporean Chinese men and women, with an average of 17.7 years of follow-up. Information on tea and coffee consumption and other lifestyle factors was collected through in-person interviews at baseline. Multivariable Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations with adjustment for potential confounders.

RESULTS

There were 1486 incident lung cancer cases. Compared to non-daily coffee drinkers, HRs (95% CIs) of lung cancer risk for those consuming one, two, and three or more cups of coffee per day were 1.18 (1.02-1.36), 1.21 (1.05-1.40), and 1.32 (1.08-1.62) respectively (P for trend = 0.0034). The highest category of black tea consumption (at least 2 cups per day) was inversely associated with risk of lung cancer [HR (95% CI) = 0.73 (0.53-0.99)], particularly among men [HR (95% CI) = 0.67 (0.47-0.95)], compared to less-than-weekly black tea drinkers, although the interaction by sex was not statistically significant.

CONCLUSIONS

Coffee beverage consumption was associated with higher risk of developing lung cancer. On the other hand, black tea intake was associated with lower risk of lung cancer among men in our cohort, and further studies are needed to confirm this association.

Mother-Infant Bonding and Emotional Availability at 12-Months of Age: The Role of Early Postnatal Bonding, Maternal Substance Use and Mental Health

INTRODUCTION

The quality of the mother-child relationship in the first year of life has far reaching implications across the life course (Bornstein in Annu Rev Psychol 65:121-158, 2014). Yet little is known about predictors of maternal bonding and emotional availability in early infancy. In this study we examined the extent to which postnatal bonding, maternal mental health, and substance use at 8-weeks postpartum predicted mother-infant bonding (self-report) and mother emotional availability (observational) at 12-months of age.

METHODS

Data were obtained from an Australian longitudinal cohort study of pregnancy (n = 308). Data were collected during pregnancy, at birth, and postnatally at 8-weeks and 12-months.

RESULTS

The results show strong continuity between postnatal bonding at 8-weeks and 12-months. Early postpartum stress and depression were associated with bonding at 12-months; however, the effect did not persist after adjustment for bonding at 8-weeks. Tobacco use at 8-weeks, but no other indicators of mental health, predicted lower emotional availability scores at 12-months.

DISCUSSION

Results suggest that the mother's felt bond to her child is stable across the first year of life and that early bonding is a more robust indicator of bonding at 12-months than a mother's mental health or substance use. These findings point to the importance of clinical and public health investments in establishing a strong bond between mother and child in the early postpartum period.

Pharmacogenomic Variants and Drug Interactions Identified Through the Genetic Analysis of Clozapine Metabolism

OBJECTIVE

Clozapine is the only effective medication for treatment-resistant schizophrenia, but its worldwide use is still limited because of its complex titration protocols. While the discovery of pharmacogenomic variants of clozapine metabolism may improve clinical management, no robust findings have yet been reported. This study is the first to adopt the framework of genome-wide association studies (GWASs) to discover genetic markers of clozapine plasma concentrations in a large sample of patients with treatment-resistant schizophrenia.

METHODS

The authors used mixed-model regression to combine data from multiple assays of clozapine metabolite plasma concentrations from a clozapine monitoring service and carried out a genome-wide analysis of clozapine, norclozapine, and their ratio on 10,353 assays from 2,989 individuals. These analyses were adjusted for demographic factors known to influence clozapine metabolism, although it was not possible to adjust for all potential mediators given the available data. GWAS results were used to pinpoint specific enzymes and metabolic pathways and compounds that might interact with clozapine pharmacokinetics.

RESULTS

The authors identified four distinct genome-wide significant loci that harbor common variants affecting the metabolism of clozapine or its metabolites. Detailed examination pointed to coding and regulatory variants at several CYP* and UGT* genes as well as corroborative evidence for interactions between the metabolism of clozapine, coffee, and tobacco. Individual effects of single single-nucleotide polymorphisms (SNPs) fine-mapped from these loci were large, such as the minor allele of rs2472297, which was associated with a reduction in clozapine concentrations roughly equivalent to a decrease of 50 mg/day in clozapine dosage. On their own, these single SNPs explained from 1.15% to 9.48% of the variance in the plasma concentration data.

CONCLUSIONS

Common genetic variants with large effects on clozapine metabolism exist and can be found via genome-wide approaches. Their identification opens the way for clinical studies assessing the use of pharmacogenomics in the clinical management of patients with treatment-resistant schizophrenia.

Risk factors associated to tobacco and alcohol use in a large French cohort of pregnant women

Tobacco and/or alcohol use during pregnancy is a major public health concern. The aim of our study was to identify risk factors associated to maternal alcohol and tobacco use assessed by maternal self-reports combined with biological measurements in meconium samples of cotinine and ethylglucuronide which reflect fetal exposure to tobacco and alcohol, respectively, during the 3rd trimester of pregnancy. We conducted a prospective study in three maternity hospitals in a large urban area during consecutive weeks (2010 and 2011). Maternal sociodemographic and clinical characteristics were assessed after delivery, using the French version of the Addiction Severity Index. Cotinine and ethylglucuronide were measured in meconium samples. Seven hundred and twenty-four women were included, and 645 meconium samples collected. Using multivariate analyses, we found that not being married or having a smoking partner predicts maternal tobacco use. In contrast, a decreased risk was associated with higher education level and wanted pregnancy. The risk for alcohol use increased when the mother had been in conflict with any relative or her partner for a long time throughout her life, as well as in case of previous treatment for any mental or emotional disorder. Using multivariate analyses and cotinine presence in meconium samples, the risks were similar except for marital status, which was not associated to cotinine presence. Community education and prevention programs should urgently be improved for all women of childbearing age with a special focus on those with past histories of mental or emotional disorders and addictive disorders. Smoking cessation should be recommended to both parents.

Daily Patterns of Caffeine Intake and the Association of Intake with Multiple Sociodemographic and Lifestyle Factors in US Adults Based on the NHANES 2007-2012 Surveys

BACKGROUND

Caffeine increases alertness when consumed in single servings of various products including coffee, tea, soft drinks, and energy drinks. Although not a nutrient, caffeine is consumed by 90% of the adult population in the United States.

OBJECTIVE

This study examined the daily pattern of caffeine intake and its relationship to multiple demographic variables.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) 2007-2012 (adults aged 19+ years; n=16,173) were used to determine the time of day at which caffeine is consumed and demographic factors associated with intake. Regression analyses characterized factors associated with caffeine intake including sex, age, ethnicity, education, smoking status, physical activity, employment status, total work hours, alcohol, and energy intake.

RESULTS

Mean adult per capita caffeine intake was 169±4 mg/d (mean±standard error). Most caffeine (70%) was consumed before noon, often at breakfast, and intake decreased progressively over the day, with little consumed after 9:00 pm. Intake was associated with age, ethnicity, smoking status, total calorie intake, and work hours (P<0.01) but not physical activity, economic status, education level, or employment status. Variables with the largest associations with intake were, respectively, ethnicity and age. Non-Hispanic black individuals consumed the smallest amounts (80±2 mg/d), non-Hispanic white individuals consumed the greatest amounts (194±3 mg/d), and Asian individuals (126±7 mg/d) and Hispanic individuals consumed intermediate amounts (127±3 mg/d). Middle-aged individuals (aged 50 to 54 years) consumed more caffeine (211±6 mg/d) than younger (107±4 mg/d, aged 20 to 24 years) and older individuals (153±4 mg/d, aged 75 to 79 years).

CONCLUSION

Most caffeine is consumed in the morning, when alertness is lowest, and very little in the evening before sleep. Ethnicity and age were the variables most strongly associated with intake; work hours, occupation, energy and alcohol intake, and smoking were also associated with intake. Because caffeine increases alertness, it is not surprising that its pattern of consumption and factors associated with its intake vary from those of most other food constituents.

The impact of maternal lifestyle factors on periconception outcomes: a systematic review of observational studies

The main risk factors for important reproductive health issues such as subfertility and perinatal mortality largely originate in the periconception period. To evaluate associations between modifiable maternal lifestyle factors and periconception outcomes, a systematic search was conducted for relevant studies published from 1990 to February 2017 on Embase, Medline, Web of Science, Cochrane database, PubMed and Google Scholar. The initial search identified 6166 articles, of which 49 studies were eligible for inclusion. Fecundity (the capacity to have a live birth) showed significant inverse associations with smoking, alcohol use and poor diet. Studies regarding time to pregnancy showed a decline in fecundity ratios (the monthly conception rate among exposed relative to unexposed couples) with increasing body mass index (BMI). Furthermore, risk of first-trimester miscarriage was found to be increased in smokers, alcohol and caffeine consumers, and with increasing BMI. Vitamin supplement use showed a decrease in this risk. This review demonstrates that maternal modifiable lifestyle factors affect periconception outcomes. If couples planning a pregnancy are more aware and supported to adopt healthy lifestyles during the periconceptional 'window of opportunity', short-term reproductive health as well as health in later life and even of future generations can be further improved.