Evidence map›Paper›PMID 42993332›Full record

Trial reportEuropean journal of nutrition2026

Acute effects of hibiscus tea versus coffee consumption before prolonged sitting on blood pressure and heart rate variability in adults: a randomized crossover trial.

Hadeel Almalki, Muhanad Aljberee, Sarah Marzouq Alotaibi, Hajar Mohammed Alharbi, Abdullah Bandar Alansare

Abstract readRandomized Controlled TrialComparative Study
PubMed Publisher
In one paragraph

Trial report in European journal of nutrition, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Hadeel Almalki *Sports Health Department, College of Sport Sciences and Physical Activity, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia.
Muhanad AljbereeDepartment of Exercise Physiology, College of Sport Sciences and Physical Activity, King Saud University, King Khalid Rd, B69-G1 Building, Riyadh, 80200, Saudi Arabia.
Sarah Marzouq AlotaibiDepartment of Exercise Physiology, College of Sport Sciences and Physical Activity, King Saud University, King Khalid Rd, B69-G1 Building, Riyadh, 80200, Saudi Arabia.
Hajar Mohammed AlharbiDepartment of Exercise Physiology, College of Sport Sciences and Physical Activity, King Saud University, King Khalid Rd, B69-G1 Building, Riyadh, 80200, Saudi Arabia.
Abdullah Bandar Alansare *Department of Exercise Physiology, College of Sport Sciences and Physical Activity, King Saud University, King Khalid Rd, B69-G1 Building, Riyadh, 80200, Saudi Arabia. aalansare@ksu.edu.sa.ORCID https://orcid.org/0000-0003-3814-6243

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeTo compare acute effects of consuming hibiscus tea and coffee before prolonged uninterrupted sitting on blood pressure (BP) and heart rate variability (HRV) in young, healthy adults.

methodsIn a randomized crossover trial, participants (n = 24; 24.9 [4.9] years old; 50% women; 54.2% with overweight/obesity) completed two 3-hour prolonged uninterrupted sitting sessions after consuming hibiscus tea or coffee. A Polar H10 heart rate (HR) strap connected to a Polar V800 monitor evaluated HRV indices, including HR, standard deviation of normal R-R intervals (SDNN), root mean square of successive differences (RMSSD), low-frequency power (LF), and high-frequency power (HF). A sphygmomanometer (Welch Allyn Connex) measured systolic (SBP) and diastolic (DBP) BP, and mean arterial pressure (MAP) was calculated. HRV indices were natural log-transformed (ln) due to skewness. Generalized linear mixed models with random effects examined the influence of both beverages on BP and HRV while adjusting for baseline values.

resultsSBP, DBP, and MAP were significantly lower (β = - 4.2, - 3.3, - 3.6 mmHg, respectively), and lnHF (β = 0.3) was significantly higher in the hibiscus tea condition compared with the coffee condition (p < 0.05 for all). No other significant differences were detected for other HRV indices (p > 0.05 for all). Sex- and BMI-stratified analyses suggested potential variation in cardiovascular responses across subgroups, although these findings should be interpreted cautiously as formal interaction tests were not performed.

conclusionsThese findings suggest that hibiscus tea may have potential to favorably modulate cardiovascular responses to prolonged uninterrupted sitting compared with coffee, although further controlled studies are needed to confirm these effects and establish their long-term implications.

Indexed as

Blood PressureCoffeeHeart RateHibiscusTeaAdultCross-Over StudiesFemaleHumansMaleSedentary BehaviorSitting PositionYoung AdultCoffeeTeaBioactive compoundsCardiovascular healthDrinksNutritionPolyphenol-rich beveragesSedentary behavior

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.