Coffee and Caffeine Consumption and Risk of Cardiovascular Disease

Written by Joyce Smith, BS. Study reveals that drinking more than six cups of coffee per day is associated with an increased risk of cardiovascular disease.

Coffee drinking is a worldwide experience, ¹ with an estimated 3 billion cups of coffee consumed daily ². While its benefits and risks have been studied and debated for decades, caffeine, the most prominent and active component in coffee, has been linked to increased blood pressure (BP) in randomized controlled trials ³, yet observational studies have implied no risk. A recent meta-analysis of 36 prospective studies (1,279,804 participants and 36,352 cases of CVD) has concluded that 3-5 cups of coffee per day is most beneficial ⁴ and suggested a U-shaped association between habitual coffee intake and CVD risk. However, heavy consumption is not associated with elevated risk possibly due to coffees  antioxidant  and anti-inflammatory  components ⁵ including  phenolic compounds, diterpenes, trigonelline, and melanoidins ⁶.

Coffee drinkers who carry the functional variant (CYP1A2) at cytochrome 450 1A2, may be less effective at metabolizing caffeine ⁷ and at  greater risk of myocardial infarction and  hypertension ⁸. Zhou et al, in a current 2019 study, ⁹ explored the ability of the CYP1A2 caffeine-metabolizing gene to better process caffeine, and identified increased risks of hypertension and cardiovascular disease relative to coffee consumption and genetic variations. The UK Biobank is a large prospective cohort study of half a million 37-73 year old participants from 22 centers across the United Kingdom whose objective is to explore better disease prevention, diagnosis, and treatment for middle age and  older individuals ¹⁰. Zhou’s team utilized the available genetic data and information on habitual coffee drinkers and their relevant covariates for 347,077people in the UK Biobank, including 8368 cases of cardiovascular disease. Using logistic regression, they investigated a possible association between coffee intake and risk of CVD, and whether the CYP1A2 genotype or caffeine metabolism might affect the association.

They found that, in line with earlier meta-analysis of prospective studies ⁴, nondrinkers, drinkers of  decaffeinated coffee and those who reported drinking less than 6 cups of coffee/day had an increased risk of CVD (11%, 7%, and 22% respectively, P=0.013) compared to those who drank 1-2 cups per day.

There was no association of CYP1A2 genotype and caffeine metabolism with CVD (P≥0.53 for all comparisons). There was also no evidence to support an interaction between the CYP1A2 genotype or caffeine-GS and coffee intake with respect to CVD risk (P≥0.53).

Among coffee drinkers, researchers found a strong inverse association between habitual coffee drinking and systolic and diastolic blood pressures. Compared to participants who drank 1-2 cups of caffeinated coffee per day, those drinking decaffeinated coffee had on average lower blood pressure.

In conclusion, heavy coffee consumption was associated with a modest increase in CVD risk. Researchers found no evidence that this association is modified by genetic variants affecting caffeine metabolism.

Source: Ang Zhou, and Elina Hyppönen. “Long-term coffee consumption, caffeine metabolism genetics, and risk of cardiovascular disease: a prospective analysis of up to 347,077 individuals and 8368 cases.” The American journal of clinical nutrition 109, no. 3 (2019): 509-516.

© 2019 American Society for Nutrition. All rights reserved.

Click here to read the full text study.

Posted October 21, 2019.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

1. Fredholm BB, Battig K, Holmen J, Nehlig A, Zvartau EE. Actions of caffeine in the brain with special reference to factors that contribute to its widespread use. Pharmacol Rev. 1999;51(1):83-133.
2. Organization IC. Interntional Coffee Organization Annual Review. 2015-2016.
3. Mesas AE, Leon-Munoz LM, Rodriguez-Artalejo F, Lopez-Garcia E. The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis. Am J Clin Nutr. 2011;94(4):1113-1126.
4. Ding M, Bhupathiraju SN, Satija A, van Dam RM, Hu FB. Long-term coffee consumption and risk of cardiovascular disease: a systematic review and a dose-response meta-analysis of prospective cohort studies. Circulation. 2014;129(6):643-659.
5. Grosso G, Godos J, Galvano F, Giovannucci EL. Coffee, Caffeine, and Health Outcomes: An Umbrella Review. Annual review of nutrition. 2017;37:131-156.
6. Chuang YH, Quach A, Absher D, Assimes T, Horvath S, Ritz B. Coffee consumption is associated with DNA methylation levels of human blood. European journal of human genetics : EJHG. 2017;25(5):608-616.
7. Cornelis MC, El-Sohemy A, Kabagambe EK, Campos H. Coffee, CYP1A2 genotype, and risk of myocardial infarction. Jama. 2006;295(10):1135-1141.
8. Soares RN, Schneider A, Valle SC, Schenkel PC. The influence of CYP1A2 genotype in the blood pressure response to caffeine ingestion is affected by physical activity status and caffeine consumption level. Vascul Pharmacol. 2018;106:67-73.
9. Zhou A, Hypponen E. Long-term coffee consumption, caffeine metabolism genetics, and risk of cardiovascular disease: a prospective analysis of up to 347,077 individuals and 8368 cases. Am J Clin Nutr. 2019;109(3):509-516.
10. Sudlow C, Gallacher J, Allen N, et al. UK biobank: an open access resource for identifying the causes of a wide range of complex diseases of middle and old age. PLoS Med. 2015;12(3):e1001779.