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Cited by 60Coffee research and impactsGastrointestinal motility and disordersStress Responses and Cortisol

Acute Effects of Coffee Consumption on Self-Reported Gastrointestinal Symptoms, Blood Pressure and Stress Indices in Healthy Individuals

Open access
Papakonstantinou, Emilia, Kechribari, Ioanna, Sotirakoglou, Κyriaki, Tarantilis, Petros, Gourdomichali, Theodora, Michas, George, Kravvariti, Vassiliki, Voumvourakis, Konstantinos +1 more·2015·Nutrition Journal
DOI 10.1186/s12937-016-0146-0PMC PMC4791892
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Abstract

BACKGROUND: It has been suggested that coffee may affect the gut-brain axis with conflicting outcomes. Moreover, there is insufficient evidence to determine whether the type or temperature of coffee consumed will have a different impact on the gut-brain axis. The purpose of this study was to investigate the effects of acute coffee consumption on the following: 1. self-reported GI symptoms and salivary gastrin, 2. stress indices [salivary cortisol and alpha-amylase (sAA)] and psychometric measures, and 3. blood pressure (BP), in healthy, daily coffee consuming individuals in non-stressful conditions. METHODS: This was a randomized, double blind, crossover clinical trial, in which 40 healthy individuals (20 men, 20 women), 20-55 years of age, randomly consumed four 200 ml coffee beverages containing 160 mg caffeine (hot and cold instant coffee, cold espresso, hot filtered coffee), 1 week apart. Salivary samples and psychometric questionnaires were collected at baseline and post-coffee consumption at 15,30, and 60 min for salivary gastrin and sAA measurements and at 60,120, and 180 min for cortisol measurements. BP was measured at beginning and end of each intervention. ClinicalTrials.gov ID: NCT02253628 RESULTS: Coffee consumption significantly increased sAA activity (P = 0.041), with significant differences only between cold instant and filter coffee at 15 and 30 min post-consumption (P < 0.05). Coffee temporarily increased salivary gastrin, without differences between coffee types. Coffee did not affect salivary cortisol or self-reported anxiety levels. Coffee consumption significantly increased BP, within the healthy physiological levels, in a gender specific manner at the end of the experimental periods, without differences between coffee types. CONCLUSION: Acute coffee consumption in non-stressful conditions activated sAA and BP but not salivary cortisol, indicating activation of the sympathetic nervous system. Post-coffee sAA increase without a concomitant cortisol increase may also indicate that coffee may have some anti-stress properties.

AI snapshot

Written from the paper’s full text.

TL;DR

In a randomized, double-blind crossover trial of 40 healthy daily coffee consumers, acute consumption of four 200-mL coffees containing 160 mg caffeine increased salivary alpha-amylase and blood pressure but did not raise salivary cortisol or self-reported anxiety. The authors interpret this as sympathetic nervous system activation with possible anti-stress properties, while salivary gastrin rose only temporarily and coffee-type differences were limited.

Key findings

  • Salivary alpha-amylase (sAA) increased after all coffees (main effect of coffee P < 0.001; coffee × time P = 0.003; time P < 0.001), peaked at 30 min, and cold instant coffee produced higher sAA than filter coffee at 15, 30, and 60 min (P < 0.05); cold instant coffee also had higher iAUC than filter coffee (P < 0.001) and hot instant coffee (P = 0.007).
  • Salivary gastrin increased temporarily after coffee (time effect P < 0.001 for each coffee type) with no differences between coffee types, and coffee had no effect on self-reported GI symptoms or other psychometric measures.
  • Salivary cortisol did not increase; it declined over time (P < 0.001 for each coffee type) with no coffee-type differences, and self-reported anxiety levels did not change.
  • Blood pressure increased within healthy physiological levels at the end of the experimental periods, without differences between coffee types; total-sample systolic BP rose from about 116.7–118.5 mmHg at baseline to 120.0–122.6 mmHg at end, and diastolic BP from about 75.3–78.2 mmHg to 79.1–80.2 mmHg, with a main effect of gender for systolic BP (P < 0.001).

Methods

  • Randomized, double-blind, crossover clinical trial in 40 healthy volunteers (20 men, 20 women), 20–55 years old, BMI ≥18.5 and <27 kg/m², daily coffee consumers, studied under non-stressful conditions.
  • Participants consumed four 200-mL coffee beverages containing 160 mg caffeine and 7.5 g white sugar—hot instant, cold instant, cold espresso, and hot filtered coffee—1 week apart; salivary samples were collected at baseline and 15, 30, and 60 min for gastrin and sAA and at 60, 120, and 180 min for cortisol, with BP measured at the beginning and end.
  • Main analysis used repeated-measures ANOVA with coffee type and time as within-subject factors and gender as a between-subject factor where relevant; AUC was calculated by the trapezoid rule, multiple comparisons used Tukey tests, and P < 0.05 was considered significant.

Limitations

  • The paper states that salivary gastrin measurement relies on only one study showing a positive plasma–saliva gastrin correlation (rho = 0.899, P < 0.001), so further confirmation is needed; it also states that long-term clinical trials are needed to confirm the results.
  • The study is acute, conducted in non-stressful conditions, and includes only healthy daily coffee consumers with no non-coffee or placebo control, so it cannot isolate caffeine from other coffee components or assess long-term effects.
  • Evident from the text: the sample is small (n = 40), mostly young and of high socioeconomic/education status, limiting generalizability; additionally, Table 3 appears inconsistent with the text for men’s systolic BP, showing lower end values than baseline despite the reported overall BP increase.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1186/s12937-016-0146-0

Cites

76 of 76 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 18 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Acute coffee consumption significantly increased salivary alpha-amylase (sAA) activity in healthy daily coffee-consuming individuals under non-stressful conditions.

    “Coffee consumption significantly increased sAA activity (P = 0.041), with significant differences only between cold instant and filter coffee at 15 and 30 min post-consumption (P < 0.05).”
    • Also stated in: § Results · plain
      “We found a significant main effect of coffee (P = <0.001), a significant coffee x time interaction (P = 0.003) and a significant time interaction (P < 0.001) for sAA.”
    • Also stated in: § Results · plain
      “sAA concentrations increased significantly after consumption of all test coffees (P < 0.001; Table 2, Fig 2b), peaked at 30 min, and did not significantly differ between 30 and 60 min post-coffee consumption (Table 2).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Volunteers complied with the pre-test restrictions (no caffeine, alcohol, exercise, adequate sleep, fasting, same foods).
    • Rests on an assumption: The experimental sessions were conducted under non-stressful conditions.
  • Findingown data

    Coffee consumption did not affect self-reported anxiety levels.

    “Coffee did not affect salivary cortisol or self-reported anxiety levels.”
    • Also stated in: § Results · plain
      “There was no main effect of coffee or coffee x time or time interactions for self-reported anxiety levels (Table 2).”
    Quote in the paperSubstantial claim
  • Findingown data

    Acute consumption of instant coffee, espresso, and filter coffee did not increase salivary cortisol concentrations in men or women.

    “without a concomitant increase in salivary cortisol”
    • Also stated in: § Discussion · plain
      “In our study, coffee consumption did not affect salivary cortisol concentrations in men or in women, which is in agreement with some studies [60–62], but not all [25–27, 29, 63].”
    • Also stated in: § Conclusion · plain
      “without effects on salivary cortisol or self-reported anxiety levels.”
    Quote in the paperSubstantial claim
  • Findingown data

    At 15, 30, and 60 min post-consumption, sAA concentrations were significantly higher after cold instant coffee than after filter coffee.

    “At 15, 30, and 60 min post-coffee consumption, the sAA concentrations were significantly higher after the consumption of cold instant coffee compared to filter coffee (P < 0.05; Table 2)”
    Quote in the paperSubstantial claim
  • Findingown data

    In normotensive healthy individuals, coffee consumption significantly increased blood pressure 3 h post-consumption.

    “In our study, we found that coffee consumption significantly increased BP, within the healthy physiological levels, in a gender specific manner in normotensive healthy individuals 3 h post-consumption, without differences between coffee types”
    • Also stated in: § Conclusion · plain
      “increased significantly BP, within the healthy physiological levels, without differences between coffee types.”
    Quote in the paperSubstantial claim
  • May combine two claims. 20
  • Classified as probably not a substantial claim. 12

  • May combine two claims.

    Findingown data

    Acute coffee consumption temporarily increased salivary gastrin concentrations, without differences between coffee types.

    “Coffee temporarily increased salivary gastrin, without differences between coffee types.”
    • Also stated in: § Results · plain
      “We found no significant main effect of coffee or coffee x time interaction, but did find a significant time interaction (P < 0.01) for salivary gastrin.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Volunteers complied with the pre-test restrictions (no caffeine, alcohol, exercise, adequate sleep, fasting, same foods).

  • May combine two claims.

    Findingown data

    Coffee consumption significantly increased blood pressure within healthy physiological levels at the end of the experimental periods, without differences between coffee types.

    “Coffee consumption significantly increased BP, within the healthy physiological levels, in a gender specific manner at the end of the experimental periods, without differences between coffee types.”
    • Also stated in: § Results · plain
      “Coffee consumption increased BP within the healthy physiological levels at the end of the experimental periods (Table 3), but without differences between coffee types.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Volunteers complied with the pre-test restrictions (no caffeine, alcohol, exercise, adequate sleep, fasting, same foods).

  • May combine two claims.

    Findingown data

    Cold instant coffee did not differ from hot instant coffee, and filter coffee did not differ from cold espresso in sAA concentrations.

    “cold instant coffee did not differ from hot instant coffee, and filter coffee did not differ from cold espresso (Table 2; Fig 2b).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    The scores on psychometric questionnaires imply that participants had moderately high perceived stress but normal self-reported anxiety and depression levels.

    “The scores on the psychometric questionnaires imply that our participants had moderately high perceived stress but normal self-reported anxiety and depression levels (Table 1).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    There were no differences in iAUC for sAA between cold instant coffee and cold espresso, between filter coffee and hot instant coffee, or between filter coffee and cold espresso.

    “without differences between cold instant coffee and cold espresso or between filter coffee and hot instant coffee or cold espresso.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In this study, salivary gastrin concentrations were only temporarily increased after coffee consumption, independent of coffee temperature.

    “In our study, we found that salivary gastrin concentrations were only temporarily increased after coffee consumption, independent of coffee temperature [22]”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    All coffee types, independently of gender, increased sAA activity with a significant main effect of coffee, coffee by time and time interactions.

    “In our study, all coffee types, independently of gender, increased sAA activity with a significant main effect of coffee, coffee by time and time interactions.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    sAA concentrations peaked at 30 min and did not significantly differ between 30 and 60 min post-coffee consumption.

    “sAA concentrations increased significantly after consumption of all test coffees (P < 0.001; Table 2, Fig 2b), peaked at 30 min, and did not significantly differ between 30 and 60 min post-coffee consumption (Table 2).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Volunteers reported an average score of 1.0 out of 10 for all questions pertaining to negative GI symptoms and a score of 9.0 out of 10 for all questions pertaining to positive feelings.

    “Volunteers reported an average score of 1.0 out of 10 for all the questions pertaining to negative GI symptoms (i.e., abdominal discomfort, bloating, dyspepsia, and heartburn), chronic stress and negative feelings and a score of 9.0 out of 10 for all the questions pertaining to positive feelings (Data not shown).”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The self-reported scale questionnaire developed by the clinical psychologist validly measures GI symptoms and psychological state.

  • May combine two claims.

    Findingown data

    There was a main effect of gender (P<0.001) and time (P<0.001) only for systolic BP, but without significant interactions.

    “There was a main effect of gender (P < 0.001) and time (P < 0.001) only for systolic BP (Table 3), but without a significant main effect of coffee, coffee x time, coffee x gender or gender x time interactions.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The subjects in this study were in non-stressful conditions with minimal anxiety levels, as explored during pre-enrolment screening.

    “Our results on the lack of a coffee effect on salivary cortisol may also be because of the non-stressful conditions and minimal anxiety levels of our subjects, as explored during the pre-enrolment screening of our study.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    The study had 80% power (α=0.05) to detect differences of 12.6 pg/ml in gastrin and 0.2 μg/ml in cortisol.

    “The study had 80 % power (α = 0.05) to detect differences between dietary groups of 12.6 pg/ml in gastrin and 0.2 μg/ml in cortisol.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given

    Neither participants nor investigators were aware of the sequence or content of paper cups.

    “neither the participants nor the investigators were aware of the sequence or the content of paper cups.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Acute coffee consumption in non-stressful conditions activated sAA and BP but not salivary cortisol, indicating activation of the sympathetic nervous system.

    “Acute coffee consumption in non-stressful conditions activated sAA and BP but not salivary cortisol, indicating activation of the sympathetic nervous system.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The experimental sessions were conducted under non-stressful conditions.

  • Classified as probably not a substantial claim.

    Study design and conductown data

    Allocation of participants used a computer-generated list of random numbers.

    “For allocation of the participants, a computer-generated list of random numbers was used (http://www.random.org/sequences/).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductcitation

    Reporting of the study conforms to CONSORT-revised and EQUATOR guidelines.

    “Reporting of the study conforms to CONSORT-revised along with references to CONSORT-revised and the broader EQUATOR guidelines [56].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [56] Simera I, Moher D, Hoey J, Schulz KF, Altman DG. A catalogue of reporting guidelines for health research. Eur J Clin Invest. 2010;40(1):35–53. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductown data

    The study was a randomized, double blind, crossover clinical trial.

    “This was a randomized, double blind, crossover clinical trial, in which 40 healthy individuals (20 men, 20 women), 20–55 years of age, randomly consumed four 200 ml coffee beverages containing 160 mg caffeine (hot and cold instant coffee, cold espresso, hot filtered coffee), 1 week apart.”
    • Also stated in: § Subjects · plain
      “participated in this randomized, double blind, crossover study.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    sAA is a convenient marker, easily collected and measured in saliva, and is recognized as both a soothing/relaxation index and a stress response marker.

    “sAA is a convenient marker and is easily collected and measured in saliva [36, 42–44]; it is recognized as both a soothing/relaxation index [45] and a stress response marker [36].”
    Quote in the paperSubstantial claim0 of 5 sources checked
    • cites [36] Nater UM, Rohleder N. Salivary alpha-amylase as a non-invasive biomarker for the sympathetic nervous system: current state of research. Psychoneuroendocrinology. 2009;34(4):486–96. source

      Not checked in the free run.

    • cites [42] Granger DA, Kivlighan KT, el-Sheikh M, Gordis EB, Stroud LR. Salivary alpha-amylase in biobehavioral research: recent developments and applications. Ann N Y Acad Sci. 2007;1098:122–44. source

      Not checked in the free run.

    • cites [43] Nater UM, Rohleder N, Schlotz W, Ehlert U, Kirschbaum C. Determinants of the diurnal course of salivary alpha-amylase. Psychoneuroendocrinology. 2007;32(4):392–401. source

      Not checked in the free run.

    • cites [44] Rohleder N, Nater UM. Determinants of salivary alpha-amylase in humans and methodological considerations. Psychoneuroendocrinology. 2009;34(4):469–85. source

      Not checked in the free run.

    • cites [45] Takai N, Yamaguchi M, Aragaki T, Eto K, Uchihashi K, Nishikawa Y. Effect of psychological stress on the salivary cortisol and amylase levels in healthy young adults. Arch Oral Biol. 2004;49(12):963–8. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    GI disturbances are not coffee or gastrin related, but possibly associated with medium to intense physiological and/or psychological stress.

    “this finding indicates that GI disturbances are not coffee or gastrin related, but possibly associated with medium to intense physiological and/or psychological stress, as has been reported in both clinical trials and population studies [2, 9–11].”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [2] Konturek PC, Brzozowski T, Konturek SJ. Stress and the gut: pathophysiology, clinical consequences, diagnostic approach and treatment options. J Physiol Pharmacol. 2011;62(6):591–9.

      Not checked in the free run.

    • cites [9] De Giorgi F, Sarnelli G, Cirillo C, Savino IG, Turco F, Nardone G, et al. Increased severity of dyspeptic symptoms related to mental stress is associated with sympathetic hyperactivity and enhanced endocrine response in patients with postprandial distress syndrome. Neurogastroenterol Motil. 2013;25(1):31–8. e2-3. source

      Not checked in the free run.

    • cites [10] Stanghellini V. Relationship between upper gastrointestinal symptoms and lifestyle, psychosocial factors and comorbidity in the general population: results from the Domestic/International Gastroenterology Surveillance Study (DIGEST). Scand J Gastroenterol Suppl. 1999;231:29–37.

      Not checked in the free run.

    • cites [11] Wang JH, Luo JY, Dong L, Gong J, Tong M. Epidemiology of gastroesophageal reflux disease: a general population-based study in Xi'an of Northwest China. World J Gastroenterol. 2004;10(11):1647–51. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    One person not involved in data handling and analysis was responsible for the test coffee allocation.

    “One person, not involved in data handling and analysis, was responsible for the test coffee allocation.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Body weight remained stable throughout the study.

    “Body weight remained stable throughout the study.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductown data

    There was no significant main effect of gender and no gender x coffee interaction for salivary gastrin, salivary cortisol, sAA and psychometric evaluations.

    “There was no significant main effect of gender and no gender x coffee interaction for salivary gastrin, salivary cortisol, sAA and psychometric evaluations, and therefore, our results are presented for the entire sample.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Gastrin is secreted in response to a meal and can be measured in saliva.

    “Gastrin, which is secreted in response to a meal [12] and can be measured in saliva [13], thus allowing it to be evaluated in non-stressful conditions, is one of the hormones regulating the rhythm of gastric acid secretion [14].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [12] Power ML, Schulkin J. Anticipatory physiological regulation in feeding biology: cephalic phase responses. Appetite. 2008;50(2–3):194–206. source

      Not checked in the free run.

    • cites [13] Ingenito A, Catelani C, Mercaldo A, d'Agata A, Cappelli G, Andreoli F. Radioimmunoassay of gastrin in human saliva. European surgical research Europaische chirurgische Forschung Recherches chirurgicales europeennes. 1986;18(2):129–32. source

      Not checked in the free run.

    • cites [14] Richardson CT, Walsh JH, Hicks MI, Fordtran JS. Studies on the mechanisms of food-stimulated gastric acid secretion in normal human subjects. J Clin Invest. 1976;58(3):623–31. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationcitation

    When there is no parallel activation of cortisol, increased sAA activity may also indicate that the enzyme is a soothing or relaxation index.

    “However, when there is no parallel activation of cortisol, increased sAA activity may also indicate that the enzyme is a soothing or relaxation index [45].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [45] Takai N, Yamaguchi M, Aragaki T, Eto K, Uchihashi K, Nishikawa Y. Effect of psychological stress on the salivary cortisol and amylase levels in healthy young adults. Arch Oral Biol. 2004;49(12):963–8. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationnone given

    sAA activity may indicate the activation of the sympathetic nervous system to a challenge.

    “sAA activity may indicate the activation of the SNS to a challenge.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    sAA activity shows a distinct diurnal profile pattern with a pronounced decrease within 60 min after awakening and a steady increase of activity during the course of the day.

    “It has been shown that sAA activity shows a distinct diurnal profile pattern with a pronounced decrease within 60 min after awakening and a steady increase of activity during the course of the day [43].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [43] Nater UM, Rohleder N, Schlotz W, Ehlert U, Kirschbaum C. Determinants of the diurnal course of salivary alpha-amylase. Psychoneuroendocrinology. 2007;32(4):392–401. source

      Not checked in the free run.

26 of 26

  • The paper relies on this without support.

    The self-reported scale questionnaire developed by the clinical psychologist validly measures GI symptoms and psychological state.

    “The self-reported scale questionnaire was developed by the clinical psychologist of our team and was used to assess GI symptoms and the psychological state of participants.”

  • The paper relies on this without support.

    Volunteers complied with the pre-test restrictions (no caffeine, alcohol, exercise, adequate sleep, fasting, same foods).

    “The day preceding the test coffee, the volunteers were required to a) not consume anything containing caffeine, thus ruling out additive results if the previous day’s caffeine had been not fully metabolized, b) not consume alcohol, thus limiting the possibility of dehydration status effects [47], c) avoid exercise, thus reducing the possibility of dehydration status effects [48]”

  • The paper relies on this without support.

    The experimental sessions were conducted under non-stressful conditions.

    “in healthy, daily coffee consuming individuals in non-stressful conditions.”

  • The authors state this as an assumption.

    This study is the first to investigate the effects of different types of coffee on self-reported GI symptoms, salivary gastrin, stress indices such as salivary cortisol and sAA, self-reported anxiety levels, and blood pressure in healthy individuals (men and women) in non-stressful conditions.

    “This study is the first, to our knowledge, to investigate the effects of different types of coffee on self-reported GI symptoms, salivary gastrin, stress indices such as salivary cortisol and sAA, self-reported anxiety levels, and BP in healthy individuals (men and women) in non-stressful conditions.”

  • The authors state this as an assumption.

    The temperature of the coffee beverage has not been reported previously to affect sAA activity.

    “These findings indicate that the temperature of the coffee beverage may affect sAA activity, but this has not been reported previously in the literature.”
5 of 5

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Coffee consumption significantly increased salivary α-amylase activity, with significant differences only between cold instant and filtered coffee at 15 and 30 min after intake.

    “Coffee consumption significantly increased salivary α-amylase activity, with significant differences only between cold instant and filtered coffee at 15 and 30 min after intake.”

    From Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain–Gut Axis (2020) · cites this paper as [199]

    The Results report that salivary α-amylase increased significantly after all test coffees and was higher after cold instant than filter coffee at 15 and 30 minutes. They also report that this difference was significant at 60 minutes, so the claim's restriction to 15 and 30 minutes is not supported. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

  • The activation of sympathetic nervous system by coffee was interpreted as due to a possible anti-stress effect of coffee, possibly contributed by a coffee compound other than caffeine.

    “which was interpreted as due to a possible anti-stress effect of coffee [199], possibly contributed by a coffee compound other than caffeine.”

    From Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain–Gut Axis (2020) · cites this paper as [199]

    The Discussion and Conclusion (page not specified) say coffee increased salivary alpha-amylase without increasing cortisol, indicating sympathetic nervous system activation and possibly anti-stress properties. They do not say the activation was caused by an anti-stress effect or attribute it to a coffee compound other than caffeine. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

  • Participants reported very low scores for negative gastrointestinal symptoms, chronic stress, and negative feelings, and high scores for positive feelings.

    “the participants reported a very low score (1 out of 10) for all the questions pertaining to negative gastrointestinal symptoms (i.e., abdominal discomfort, bloating, dyspepsia, and heartburn), chronic stress, and negative feelings, whereas the score was high (9 out of 10) for all the questions pertaining to positive feelings.”

    From Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain–Gut Axis (2020) · cites this paper as [199]

    The Discussion (page unavailable) reports a lack of self-reported gastrointestinal disturbances in the healthy volunteers, supporting the gastrointestinal portion. Methods > Psychometric evaluations describes a 1–10 questionnaire covering symptoms and mood, but the cited passages do not report scores of 1/10 for every negative item or 9/10 for every positive item. Results > Table 1 gives a baseline perceived-stress score of 31.8/56, not the claimed very low chronic-stress score. (LLM, conf=0.82)

    Experimental — accuracy not yet measured

  • Irrespective of coffee type, salivary gastrin was temporarily increased, whereas salivary cortisol and self-reported anxiety levels were not affected.

    “Irrespective of coffee type, salivary gastrin was temporarily increased, whereas salivary cortisol or self-reported anxiety levels were not affected.”

    From Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain–Gut Axis (2020) · cites this paper as [199]

  • In a randomized, double-blind, crossover clinical trial with 40 healthy young individuals, coffee consumption had no effect on self-reported anxiety levels.

    “There was no effect of coffee on self-reported anxiety levels.”

    From Effects of Coffee and Its Components on the Gastrointestinal Tract and the Brain–Gut Axis (2020) · cites this paper as [199]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Overall systolic BP cannot equal the reported subgroup means

    Major

    For cold espresso, both the men's and women's end-of-session systolic BP means are 115.95 mmHg. With 20 participants in each group, the overall mean must also be 115.95, not 120.03 mmHg. The same issue occurs for the other three coffees.

    Reported 120.03 · recomputed 115.95

  • Claimed 60-minute cold-instant/filter difference conflicts with table notation

    Minor

    The results state that cold instant coffee produced significantly higher sAA than filter coffee at 60 minutes. In Table 2, those values have uppercase superscripts AB and A, which share A; the table note says means with no superscript in common are significantly different.

  • Abstract omits a reported 60-minute sAA difference

    Minor

    The abstract says significant differences occurred only between cold instant and filter coffee at 15 and 30 minutes. Table 2 marks cold espresso and filter coffee as significantly different at 60 minutes: their uppercase superscripts, B and A, have no letter in common.

  • Claimed absence of a filter/espresso difference conflicts with table notation

    Minor

    The results say filter coffee did not differ from cold espresso. At 60 minutes, Table 2 assigns them uppercase superscripts A and B, respectively, indicating a significant difference under the table's stated convention.

4 of 4

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Kollia M, Gioxari A, Maraki M, Kavouras SAA, Greece:, 2006. Development, validity and reliability of the Harokopio Physical Activity Questionnaire in Greek adults. Proceedings of the 8th Panhellenic Congress on Nutrition and Dietetics Beta Medical Publishing. 2006.

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Related

Authors
Papakonstantinou, E., Kechribari, I., Sotirakoglou, Κ., Tarantilis, P., Gourdomichali, T., Michas, G., Kravvariti, V., Voumvourakis, K., & Zampelas, A.
Affiliations
  • Agricultural University of Athens (GR)
  • National and Kapodistrian University of Athens (GR)
Corresponding author
Papakonstantinou, Emilia
ORCID
Venue
Nutrition Journal
Publisher
Springer Science and Business Media LLC
Published
2015-12
Volume
15
Issue
1
Pages
26-26
ISSN
1475-2891 (ISSN-L)
DOI
10.1186/s12937-016-0146-0
PMC
PMC4791892
OpenAlex
W2300199772
Semantic Scholar
a261aeee4f174ea1c3066ebbbaba02b99ad1b7c9
Cited by
59
References
76
Citations by year
2026: 6 · 2025: 3 · 2024: 11 · 2023: 3 · 2022: 8 · 2021: 6 · 2020: 6 · 2019: 3 · 2018: 7 · 2017: 5 · 2016: 1
FWCI
3.13
Type
journal article
Language
en
Open access
Licence
cc-by
Locations
  • Nutrition Journal (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
Funders
Nestlé Hellas
Topics
  • Health Sciences › Medicine › Pharmacology › Coffee research and impacts
  • Health Sciences › Medicine › Gastroenterology › Gastrointestinal motility and disorders
  • Life Sciences › Neuroscience › Behavioral Neuroscience › Stress Responses and Cortisol
Keywords
coffee consumption, caffeine, gut-brain axis, gastrointestinal symptoms, salivary amylase, salivary cortisol, blood pressure, sympathetic nervous system, anxiety, instant coffee, espresso, filtered coffee
MeSH terms
Adult, alpha-Amylases, Blood Pressure, Caffeine, Coffee, Double-Blind Method, Female, Gastrins, Humans, Hydrocortisone, Male, Middle Aged, Motor Activity, Psychometrics, Surveys and Questionnaires, Saliva, Stress, Physiological, Cross-Over Studies, Gastrointestinal Tract, Young Adult, Self Report

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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