In a large middle-aged UK cohort without cardiovascular disease, moderate to heavy coffee consumption — up to 25 cups a day — was not associated with significant changes in arterial stiffness, contradicting previous research.
The research from Queen Mary University of London, led by Professor Steffen Petersen from Queen Mary’s William Harvey Research Institute, was presented at the British Cardiovascular Society (BCS) Conference in Manchester and part-funded by the British Heart Foundation (BHF).
Arteries carry blood containing oxygen and nutrients from your heart to the rest of your body. If they become stiff, it can increase the workload on the heart and increase a person’s chance of having a heart attack or stroke.
The study of over 8,000 people in the UK debunks previous studies that claimed drinking coffee increases arterial stiffness. Previous suggestions that drinking coffee leads to stiffer arteries are inconsistent and could be limited by lower participant numbers, according to the team behind this new research. Coffee consumption was categorised into three groups for the study. Those who drink less than one cup a day, those who drink between one and three cups a day and those who drink more than three. People who consumed more than 25 cups of coffee a day were excluded, but no increased stiffening of arteries was associated with those who drank up to this high limit when compared with those who drank less than one cup a day.
The associations between drinking coffee and artery stiffness measures were corrected for contributing factors like age, gender, ethnicity, smoking status, height, weight, how much alcohol someone drank, what they ate and high blood pressure.
Of the 8,412 participants who underwent MRI heart scans and infrared pulse wave tests, the research showed that moderate and heavy coffee drinkers were most likely to be male, smoke, and consume alcohol regularly.
Dr Kenneth Fung, who led the data analysis for the research at Queen Mary University of London, said: “Despite the huge popularity of coffee worldwide, different reports could put people off from enjoying it. Whilst we can’t prove a causal link in this study, our research indicates coffee isn’t as bad for the arteries as previous studies would suggest.
“Although our study included individuals who drink up to 25 cups a day, the average intake amongst the highest coffee consumption group was 5 cups a day. We would like to study these people more closely in our future work so that we can help to advise safe limits.”
Professor Metin Avkiran, associate medical director at the British Heart Foundation, said: “Understanding the impact that coffee has on our heart and circulatory system is something that researchers and the media have had brewing for some time.
“There are several conflicting studies saying different things about coffee, and it can be difficult to filter what we should believe and what we shouldn’t. This research will hopefully put some of the media reports in perspective, as it rules out one of the potential detrimental effects of coffee on our arteries.”
Introduction: Coffee is widely reported to be the world’s most popular drink and previous studies revealed acute increases in arterial stiffness with its consumption. But, the reported chronic effects of coffee on arterial stiffness are inconsistent and limited by modest number of studied subjects.
This study aims to evaluate the association of coffee consumption on arterial stiffness using two forms of stiffness measures in a large population cohort. Aortic distensibility (AoD) is a local measure of arterial stiffness whilst arterial stiffness index (ASI) is a measure of wave reflection. Both measures have been shown to be predictors of cardiovascular events.
Methods: This cross-sectional cohort analysis comprised of 17,932 participants in the UK Biobank Imaging Study who underwent both cardiovascular magnetic resonance (CMR) imaging and pulse waveform measurements via finger probes. Participants with known cardiovascular disease were excluded. Coffee consumption habits were self-reported at the time of imaging and those who drink >25 cups/day were excluded. Coffee consumption was categorised into 3 groups (≤1, 1–3, >3 cups/day) with the lowest group used as the reference in the analyses.
AoD was derived using an automated method to obtain the maximum and minimum luminal areas in the ascending (AA) and descending aorta (DA) from cine CMR images. ASI was calculated by dividing the participant’s height by the time interval between the peaks of the waveform recorded. AoD and ASI outliers (1.5x inter-quartile range rule) were excluded. Log transformation of AoD values was performed prior to regression analyses.
Associations between coffee consumption and stiffness measures were assessed separately using univariate linear regression models adjusting for age, sex, ethnicity, Townsend deprivation index, current smoking, higher levels of education, height, weight, regular alcohol consumption (≥3 times/week), systolic blood pressure, resting heart rate, presence of hypertension, hypercholesterolaemia or diabetes, intake of vegetable, meat, water and tea consumption.
Results: Baseline characteristics of the 8,412 participants included in the final analyses are summarised in table 1. Moderate and heavy coffee drinkers were more likely to be male, smoke and consumed alcohol regularly. No significant differences were observed in the systolic blood pressures and heart rates between the groups.
The unadjusted distributions of AoD in AA and DA were similar across the 3 groups (figure 1). Our regression models found no statistically significant differences in all three arterial stiffness measures for individuals who drink 1–3 cups or >3 cups of coffee/day compared with the reference group (table 2).
Conclusion: In this large middle-aged cohort without cardiovascular disease, moderate to heavy coffee consumption was not associated with significant changes in arterial stiffness measured by AoD and ASI compared with individuals who drink ≤1 cups of coffee/day.
Kenneth Fung, Luca Biasiolli, Evan Hann, Nay Aung, Jose Paiva, Elena Lukaschuk, Mihir Sanghvi, Valentina Carapella, Jennifer Rayner, Konrad Werys, Henrike Puchta, Katharine Thomas, Niall Moon, Mohammed Khanji, Stefan Neubauer, Stefan Piechnik, Patricia B Munroe, Steffen Petersen
[link url="https://www.qmul.ac.uk/media/news/2019/smd/coffee-not-as-bad-for-heart-and-circulatory-system-as-previously-thought.html"]Queen Mary University of London material[/link]
[link url="https://heart.bmj.com/content/105/Suppl_6/A8.2"]Heart journal abstract[/link]