Coffee Consumption among Adults in the United States by Demographic Variables and Purchase Location: Analyses of NHANES 2011-2016 Data

Polyphenols vs. Caffeine in Coffee from Franchise Coffee Shops: Which Serving of Coffee Provides the Optimal Amount of This Compounds to the Body

The scientific literature indicates that there is a limited number of data on the content of bioactive components in coffees consumed "on the go". Therefore, this study examined the polyphenol and caffeine content of different types of coffee from franchise coffee shops, and the caffeine/total polyphenol ratio. The five most popular types of coffee purchased in six franchise coffee shops in Warsaw were analysed. A total of 120 coffee samples were tested. A significant positive (r = 0.7407, p < 0.001) correlation was found between the total polyphenol and caffeine content in all coffee types tested. Per unit volume, espresso coffee had the highest significant (p < 0.005) average total polyphenol and caffeine contents (232.9 ± 63.9 mg/100 mL and 198.6 ± 68.3 mg/100 mL, respectively). After taking into account the coffee's serving size, a serving of Americano provided significantly (p < 0.05) the most total polyphenol (average 223.5 ± 81.5 mg), while the highest caffeine content was provided by a serving of ice latte/latte frappe (average 136 ± 57.0 mg). The most favourable ratio of caffeine to total polyphenols (0.56) was found in a serving of Americano coffee; therefore, it seems that this coffee can be considered optimal in terms of the content of both compounds. These findings demonstrate that the polyphenol and caffeine contents of coffees offered in franchise coffee shops are closely related to the serving size.

Association of daily sitting time and coffee consumption with the risk of all-cause and cardiovascular disease mortality among US adults

BACKGROUND

Sedentary behavior has been demonstrated to be a modifiable factor for several chronic diseases, while coffee consumption is believed to be beneficial for health. However, the joint associations of daily sitting time and coffee consumption with mortality remains poorly understood. This study aimed to evaluate the independent and joint associations of daily sitting time and coffee intakes with mortality from all-cause and cardiovascular disease (CVD) among US adults.

METHODS

An analysis of a prospective cohort from the 2007-2018 National Health and Nutrition Examination Survey of US adults (n = 10,639). Data on mortality were compiled from interview and physical examination data until December 31, 2019. Daily sitting time was self-reported. Coffee beverages were from the 24-hour diet recall interview. The main outcomes of the study were all-cause and cardiovascular disease mortality. The adjusted hazard ratios [HRs] and 95% confidence intervals [CI] were imputed by Cox proportional hazards regression.

RESULTS

Among 10,639 participants in the study cohort, there were 945 deaths, 284 of whom died of CVD during the follow-up period of up to 13 years. Multivariable models showed that sitting more than 8 h/d was associated with higher risks of all-cause (HR, 1.46; 95% CI, 1.17-1.81) and CVD (HR, 1.79; 95% CI, 1.21-2.66) mortality, compared with those sitting for less than 4 h/d. People with the highest quartile of coffee consumption were observed for the reduced risks of both all-cause (HR, 0.67; 95% CI, 0.54-0.84) and CVD (HR, 0.46; 95% CI, 0.30-0.69) mortality compared with non-coffee consumers. Notably, joint analyses firstly showed that non-coffee drinkers who sat six hours or more per day were 1.58 (95% CI, 1.25-1.99) times more likely to die of all causes than coffee drinkers sitting for less than six hours per day, indicating that the association of sedentary with increased mortality was only observed among adults with no coffee consumption but not among those who had coffee intake.

CONCLUSIONS

This study identified that sedentary behavior for more than 6 h/d accompanied with non-coffee consumption, were strongly associated with the increased risk of mortality from all-cause and CVD.

Habitual caffeinated beverage consumption and headaches among adults with episodic migraine: A prospective cohort study

OBJECTIVE

To examine the relationship between habitual caffeinated beverage consumption and headache frequency, duration, and intensity in a prospective cohort of adults with episodic migraine.

BACKGROUND

Caffeine is a commonly ascribed headache trigger in adults with migraine and clinicians may counsel patients to avoid caffeinated beverages; however, few studies have examined this association.

METHODS

From March 2016 to August 2017, 101 adults with physician-confirmed episodic migraine completed baseline questionnaires, including information about caffeinated beverage consumption. For 6 weeks, they reported headache onset, duration, and pain intensity (scale 0-100) on twice-daily electronic diaries. Ninety-seven participants completed data collection. We examined associations between self-reported habitual caffeinated beverage consumption at baseline and headache outcomes prospectively captured over the following 6 weeks, adjusting for age, sex, and oral contraceptive use.

RESULTS

The adjusted mean headache days per month was similar among the 20 participants reporting no habitual intake (7.1 days, 95% confidence interval [CI] 5.1-9.2), the 65 participants reporting 1-2 servings/day (7.4 days, 95% CI 6.1-8.7), and the 12 participants reporting 3-4 servings/day (5.9 days, 95% CI 3.3-8.4). Similarly, mean headache duration (no servings/day: 8.6 h, 95% CI 3.8-13.3; 1-2 servings/day: 8.5 h, 95% CI 5.5-11.5; 3-4 servings/day: 8.8 h, 95% CI 2.3-14.9) and intensity (no servings/day: 43.8, 95% CI 37.0-50.5; 1-2 servings/day: 43.1, 95% CI 38.9-47.4; 3-4 servings/day: 46.5, 95% CI 37.8-55.3) did not differ across levels of caffeinated beverage intake, though estimates were imprecise.

CONCLUSIONS

We found no association between habitual caffeinated beverage intake and headache frequency, duration, or intensity. These data do not support a recommendation that patients with episodic migraine should avoid consuming caffeine. Further research is needed to understand whether deviating from usual caffeine intake may trigger migraine attacks.

Caffeine Consumption in Polish Adults: Development and Validation of a Polish Questionnaire for Assessing Caffeine Intake

Objective: Caffeine is one of the oldest natural substances consumed by people. Its consumption in Poland has not been well described. The aim of this study was to design and validate an online food frequency questionnaire (FFQ) on caffeine intake and to use it to estimate caffeine consumption in Polish adults.Method: The FFQ was prepared and validated in a pilot study. The intake assessment was conducted in 2019-2020 on 372 respondents, aged 18 to 60 years. The FFQ included products such as coffee, tea, energy drinks, and carbonated drinks, as well as supplements and chocolate.Results: We showed good repeatability of the FFQ and it was considered a valid tool. The mean total caffeine intake among all participants was 426.7 mg ± 283.4 mg/day of all sources; in women, it was 446.4 mg ± 306.2 mg/day, while in men, it was 394.1 ± 236.4 mg/day. Forty-three percent of the respondents consumed more than 400 mg of caffeine/day. Coffee was the main source of caffeine and contributed to 65% of total caffeine consumption. Women consumed 90% more green tea than men (p < 0.01). Overweight and obese people have 20% greater total caffeine intake (p = 0.01) and consumed 20% more coffee (p = 0.02) and 30% more black tea (p = 0.01) than people of normal weight.Conclusions: Average caffeine consumption among Polish adults slightly exceeds the safe consumption dose established by the European Food Safety Authority. Body weight status can differentiate caffeine intake.

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.

Appraisal of the causal effect of plasma caffeine on adiposity, type 2 diabetes, and cardiovascular disease: two sample mendelian randomisation study

Objective

To investigate the potential causal effects of long term plasma caffeine concentrations on adiposity, type 2 diabetes, and major cardiovascular diseases.

Design

Two sample mendelian randomisation study.

Setting

Genome-wide association study summary data for associations of two single nucleotide polymorphisms associated with plasma caffeine at the genome-wide significance threshold (rs2472297 near the CYP1A2 gene and rs4410790 near the AHR gene) and their association with the outcomes.

Participants

Primarily individuals of European ancestry participating in cohorts contributing to genome-wide association study consortia.

Main outcome measures

Outcomes studied were body mass index, whole body fat mass, whole body fat-free mass, type 2 diabetes, ischaemic heart disease, atrial fibrillation, heart failure, and stroke.

Results

Higher genetically predicted plasma caffeine concentrations were associated with lower body mass index (beta -0.08 standard deviation (SD) (95% confidence interval -0.10 to -0.06), where 1 SD equals about 4.8 kg/m² in body mass index, for every standard deviation increase in plasma caffeine) and whole body fat mass (beta -0.06 SD (-0.08 to -0.04), 1 SD equals about 9.5 kg; P<0.001) but not fat-free mass (beta -0.01 SD (-0.02 to -0.00), 1 SD equals about 11.5 kg; P=0.17). Higher genetically predicted plasma caffeine concentrations were associated with a lower risk of type 2 diabetes in two consortia (FinnGen and DIAMANTE), with a combined odds ratio of 0.81 ((95% confidence interval 0.74 to 0.89); P<0.001). Approximately half (43%; 95% confidence interval 30% to 61%) of the effect of caffeine on type 2 diabetes was estimated to be mediated through body mass index reduction. No strong associations were reported between genetically predicted plasma caffeine concentrations and a risk of any of the studied cardiovascular diseases.

Conclusions

Higher plasma caffeine concentrations might reduce adiposity and risk of type 2 diabetes. Further clinical study is warranted to investigate the translational potential of these findings towards reducing the burden of metabolic disease.

Caffeine levels and dietary intake in smokers with schizophrenia and bipolar disorder

Caffeine is one of the most widely used psychoactive drugs in the United States. High rates of caffeine use have been observed in adult smokers as well as those with serious mental illness. The current secondary analysis aimed to extend previous findings demonstrating high caffeine intake in schizophrenia by examining dietary intake of caffeine and serum caffeine levels in outpatient smokers with schizophrenia (SCZ), bipolar disorder (BP) and control smokers with no psychiatric diagnoses (CON). Two hundred forty-eight adult smokers (SCZ=80; BP=80; CON=88) were included in the current study. Adult smokers with schizophrenia, bipolar disorder, and no psychiatric diagnoses were 40.85 (SD = 11.90) years old on average and all participants were current smokers (∼20 cigarettes per day). Twenty-four hour self-reported caffeine intake (in mg) was highest among individuals with bipolar disorder (median=195.3), followed by adults with schizophrenia (median=155.0) and controls (median=131.7). Participants with bipolar disorder also had the highest serum caffeine levels (in ng/ml; median=1725), followed by those with schizophrenia (median=1194) and controls (median=613.2).  These results provide additional evidence of high caffeine intake among adults with schizophrenia and extend findings by identifying even higher rates of caffeine use in those with bipolar disorder. The current study suggests that caffeine intake is higher among subgroups of patients with serious mental illness.

Coffee and tea consumption, patient-reported, and clinical outcomes in a longitudinal study of patients with breast cancer

Background

Higher consumption of coffee and tea has been associated with improved health outcomes in the general population and improved breast cancer (BC) prognosis. This study investigated patterns of coffee and tea consumption and association with patient‐reported outcomes (PROs) and clinical outcomes among survivors of BC.

Methods

The authors included survivors of stage I–III BC enrolled in the CANTO cohort (NCT01993498) that provided post‐treatment assessment of coffee and tea consumption from years 1 to 4 after diagnosis. Group‐based trajectory modeling clustered patients according to daily consumption of coffee and tea. Multivariable mixed models and Cox models examined associations between consumption, PROs and clinical outcomes.

Results

Among 3788 patients, the authors identified four stable patterns of consumption: “Low” (25.8%), “Moderate” (37.6%), “High” (25.3%), and “Very high” (11.3%), corresponding to <1, 2, 3, and ≥ 4 cups of coffee and/or tea per day. Patients in the “Very high” group (vs. “Low”), were more likely to be younger, smokers, with higher monthly income and education. PROs and survival outcomes were similar across the four groups.

Conclusions

Over one in three survivors of BC reported high or very high consumption of coffee and/or tea. The authors found no association between higher consumption of coffee and/or tea, worse PROs and clinical outcomes.

More than 30% of survivors of breast cancer report high post‐diagnostic consumption of coffee and tea. In this study, the authors did not find any detrimental association between higher consumption of coffee and tea and patient‐reported or clinical outcomes.

The Examination of the Influence of Caffeinated Coffee Consumption on the Concentrations of Serum Prolactin and Selected Parameters of the Oxidative-Antioxidant Balance in Young Adults: A Preliminary Report

We verified whether caffeinated coffee consumption influenced the concentrations of prolactin (PRL) and oxidative stress parameters: total antioxidant status (TAS), ferric reducing antioxidant power (FRAP), total oxidant status (TOS), oxidative stress index (OSI), advanced oxidation protein products (AOPP), uric acid (UA), total bilirubin (T-Bil), albumin (ALB), iron (Fe), calcium (Ca), magnesium (Mg), and inflammatory marker C-reactive protein (CRP)—in blood sera obtained at 15, 60, and 120 minutes after caffeinated coffee intake, in relation to the fasting point. The study participants were 33 young, healthy, nonsmoking volunteers (15 men, 18 women) aged 19-29 years. PRL concentrations significantly decreased ( $p<0.05$ ) after consumption, except at time point 15’ in men ( $p>0.05$ ). In women, FRAP levels significantly increased over time, and significant changes were also observed for UA at 120’ and ALB at 15’. In men, significant changes were found for levels of AOPP at 15’, T-Bil and ALB at 15’, iron at 60’ and 120’, and calcium at 120’. There were no significant differences in the levels of other examined parameters between the defined time points. In conclusion, the substances contained in caffeinated coffee decrease the level of prolactin and may also have an impact on selected parameters of oxidative stress, which could be the basis of future research focused on the identification of new therapeutic targets.

Caffeine, Paraxanthine, Theophylline, and Theobromine Content in Human Milk

This study aimed to assess the content of caffeine and its metabolites—paraxanthine, theophylline, and theobromine—in breast milk according to selected factors. Samples of human milk were collected from 100 women living in the east–northeast region of Poland. Information on the consumption of beverages and foods containing caffeine was collected using a 3 day food record. The determination of caffeine and its metabolite content was performed using liquid chromatography–mass spectrometry (LC–MS/MS). This study research showed that more caffeine was found in the milk of women living in cities, with secondary education, aged 34–43, and also in milk from the 3rd and 4th lactation periods (p ≤ 0.05). Factors such as place of residence, level of education, age, and stage of lactation influenced the nutritional choices of breastfeeding women, which had an impact on the level of caffeine and its metabolites in breast milk. A positive correlation was found between the consumption of caffeine with food and drinks and its level in human milk.

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.

Prevalence and Amounts of Common Ingredients Found in Energy Drinks and Shots

BACKGROUND

Energy drinks are one of the most popular packaged beverage products consumed within the United States (US). Energy drinks are considered a functional beverage, a category that also includes sports drinks and nutraceutical beverages.

PURPOSE

The focus of the current study was to examine the nutrition fact panels of the top selling commercially available energy drink and energy shot products within the US to characterize common ingredient profiles to help establish a standard definition and ingredient profile of energy drinks and energy shots for consumers, health care practitioners, and researchers.

METHODS

The top 75 commercially available energy drinks and shots were identified and compiled from multiple commercial retail websites as of September 2021. For the purpose of this study, an energy drink must have met the following criteria: (A) marketed as an energy drink; (B) purported to improve energy, focus, or alertness; (C) not sold as a dietary supplement (no supplement fact panels); (D) manufactured as a pre-packaged and ready-to-drink beverage; and (E) contains at least three of (1) caffeine, (2) B-vitamins, (3) sugar, (4) taurine, (5) creatine, (6) quercetin, (7) guarana, (8) ginseng, (9) coenzyme Q10, or (10) branched chain amino acids. Energy shots must have met similar criteria to be included: (A) marketed as an energy shot; (B) purported to improve energy, focus, or alertness; (C) sold as a dietary supplement; (D) manufactured as a pre-packaged beverage with a small volume (<3.5 mL); and (E) contains at least three of the ingredients stated above.

RESULTS

Twenty energy shots and fifty-five energy drinks were included in this analysis. The number of ingredients per product (mean ± SD) was 18.2 ± 5.7, with 15 products containing proprietary blends with undisclosed ingredient amounts. The relative prevalence and average amounts of the top ingredients were as follows: caffeine (100%; 174.4 ± 81.1 mg), vitamin B6 (72%; 366.9 ± 648.1 percent daily value (%DV)), vitamin B3 (67%; 121.44 ± 69.9% DV), vitamin B12 (67%; 5244.5 ± 10,474.6% DV), vitamin B5 (37.3%; 113.6 ± 76.6% DV), and taurine (37.3%; amounts undisclosed).

CONCLUSIONS

Our findings suggest a high prevalence of caffeine and B-vitamins in these energy products, with many of the formulations containing well above the recommended daily value of B-vitamins.

Maternal caffeine intake and DNA methylation in newborn cord blood

BACKGROUND

Epigenetic mechanisms may underlie associations between maternal caffeine consumption and adverse childhood metabolic outcomes. However, limited studies have examined neonate DNA methylation (DNAm) patterns in the context of preconception or prenatal exposure to caffeine metabolites.

OBJECTIVES

We examined preconception and pregnancy caffeine exposure with DNAm alterations in neonate cord blood (n = 378).

METHODS

In a secondary analysis of the Effects of Aspirin in Gestation and Reproduction Trial (EAGeR), we measured maternal caffeine, paraxanthine, and theobromine concentrations from stored serum collected preconception (on average 2 months before pregnancy) and at 8 weeks of gestation. In parallel, self-reported caffeinated beverage intake was captured via administration of questionnaires and daily diaries. We profiled DNAm from the cord blood buffy coat of singletons using the MethylationEPIC BeadChip. We assessed associations of maternal caffeine exposure and methylation β values using multivariable robust linear regression. A false discovery rate (FDR) correction was applied using the Benjamini-Hochberg method.

RESULTS

In preconception, the majority of women reported consuming 1 or fewer servings/day of caffeine on average, and caffeine and paraxanthine metabolite levels were 88 and 36 µmol/L, respectively. Preconception serum caffeine metabolites were not associated with individual cytosine-guanine (CpG) sites (FDR >5%), though pregnancy theobromine was associated with DNAm at cg09460369 near RAB2A (β = 0.028; SE = 0.005; FDR P = 0.012). Preconception self-reported caffeinated beverage intake compared to no intake was associated with DNAm at cg09002832 near GLIS3 (β = -0.013; SE = 0.002; FDR P = 0.036). No associations with self-reported intake during pregnancy were found.

CONCLUSIONS

Few effects of maternal caffeine exposure on neonate methylation differences in leukocytes were identified in this population with relatively low caffeine consumption.

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.

The Relationship Between Caffeine and Caffeinated Drinks in Causing Intracranial Hemorrhage in the Elderly Aspirin-Taking Population: A Systematic Review

Caffeinated drinks are the most widely consumed beverages globally and their intake has increased in the elderly. Caffeine exhibits dose-dependent adverse effects. Low to moderate doses cause anxiety, restlessness, irritability, and nausea. High doses of 3-5g can affect different physiological systems and lead to detrimental effects like palpitations, hypertension, agitation, seizures, and coma. Low-dose aspirin is the most used anticoagulant in preventing ischemic vascular events. An increased risk of intracranial hemorrhage is associated with low-dose aspirin with an intensified intracerebral hemorrhage risk. The aim of this research is to explore the association between caffeine and aspirin in causing lethal intracranial hemorrhage in the older population. Because of the devastating nature of intracranial hemorrhages and the inconsistent published data on the risk of intracranial hemorrhage in individuals taking both aspirin and caffeine, we conducted a systematic review considering the elderly population. We conducted the study following the reporting guidelines for systematic review and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist. Inclusion and exclusion criteria were determined. Data was collected from PubMed, PubMed Central® (PMC), National Library of Medicine (MEDLINE), Google Scholar, Multidisciplinary Digital Publishing Institute (MDPI), and Web of Science by applying keywords and Medical Subject Headings (MeSH) terms individually. Our initial search yielded 155,270 articles, which were scrutinized, and duplicates were removed for accuracy. Of these, a total of 13 research papers were finally extracted using the PRISMA recommendations and applying other inclusion and exclusion criteria. With the help of our systematic review, we could determine that both aspirin and caffeine portrayed a role in causing intracranial hemorrhage independently, but further studies are recommended to evaluate if both could lead to similar adverse effects when taken collectively.

Correlations between Coffee Consumption and Metabolic Phenotypes, Plasma Folate, and Vitamin B12: NHANES 2003 to 2006

Metabolic syndrome (MetS) is prevalent not only among the overweight and obese but also normal weight individuals, and the phenotype is referred to as a metabolically unhealthy phenotype (MUHP). Besides normal weight individuals, overweight/obese individuals are also protected from MetS, and the phenotype is known as a metabolically healthy phenotype (MHP). Epidemiological studies indicate that coffee and micronutrients such as plasma folate or vitamin B12 (vit. B12) are inversely associated with MetS. However, correlations among coffee consumption metabolic phenotypes, plasma folate, and vit. B12 remain unknown. Our objective was to investigate the correlation between coffee consumption, metabolic phenotypes, plasma folate, and vit. B12 as well as to understand associations between plasma folate, vit. B12, and metabolic phenotypes. Associations among coffee consumption metabolic phenotypes, plasma folate, and vit. B12 were assessed in a cross-sectional study of 2201 participants, 18 years or older, from 2003-2004 and 2005-2006 National Health and Nutrition Examination Surveys (NHANES). MUHP was classified as having > three metabolic abnormalities. Coffee consumption was not associated with metabolic phenotypes, but negatively correlated with several metabolic variables, including BMI (p < 0.001). Plasma folate was positively associated with MUHP (p < 0.004), while vit. B12 was inversely associated with MUHP (p < 0.035). Our results suggest the potential protective impact of coffee on individual components of MetS and indicate a positive correlation between coffee consumption and MUHP among overweight individuals. Identifying possible dietary factors may provide practical and low-cost dietary intervention targets, specifically for early intervention. Larger and randomized intervention studies and prospective longitudinal studies are required to further evaluate these associations.

The effect of black coffee on fasting metabolic markers and an abbreviated fat tolerance test

BACKGROUND & AIMS

Coffee is typically prohibited prior to metabolic assessment in clinical and research settings. However, whether coffee meaningfully alters fasted metabolic testing or the results of a fat tolerance test is unclear. We investigated whether allowing black coffee intake within a fast prior to blood work affected fasting triglycerides (TG) and glucose, as well as the postprandial lipemic and glycemic response following an abbreviated fat tolerance test (AFTT).

METHODS

Participants completed two randomized AFTTs separated by at least 1 week. For each AFTT, participants arrived into the laboratory following a 10 h overnight fast and consumed either 8 oz of water or black coffee. Thirty minutes later, a baseline blood draw was collected. Immediately following, participants consumed a standardized high-fat shake (70% fat; 9 kcal/kg body mass), vacated the laboratory, and returned 4 h later for a follow-up blood draw.

RESULTS

Ten healthy individuals (5M, 5F; age: 22.9 ± 3.8 years; BMI: 24.3 ± 2.6 kg/m²) completed the study. There was no difference between trials with regard to baseline TG (MD = 1.7 mg/dL; p = 0.74), 4 h TG (MD = 2.7 mg/dL; p = 0.75), Δ TG (MD = 4.4 mg/dL; p = 0.52), or % change TG (MD = 7.7%; p = 0.99). Similarly, following coffee consumption, baseline glucose was unchanged relative to water (MD = 0.4 mg/dL; p = 0.84) and there were no differences in postprandial glucose measures, including 4 h (MD = 0.9 mg/dL; p = 0.58), Δ (MD = 1.3 mg/dL; p = 0.31), and % change in glucose (MD = 1.6%; p = 0.29).

CONCLUSION

In our small study sample, coffee intake prior to an AFTT did not affect baseline or postprandial TG and glucose. Therefore, coffee intake prior to an AFTT may not affect its validity.