Impact of Coffee Consumption on Physiological Markers of Cardiovascular Risk: A Systematic Review

Daneschvar HL, Smetana GW, Brindamour L, Bain PA, Mukamal KJ · The American Journal of Medicine · 2021 May

DOI 10.1016/j.amjmed.2020.09.036

Objective

To systematically review randomized controlled trials investigating the impact of coffee consumption on selected cardiovascular biomarkers, particularly focusing on its potential anti-inflammatory effects as a mechanistic basis for the observed inverse relationship between coffee consumption and the risk for cardiovascular disease.

Conclusions

The review concludes that, based on the analyzed randomized controlled studies, there is insufficient evidence to confidently assert that an anti-inflammatory effect of coffee is a major contributing factor to the lower all-cause mortality reported in observational studies. Boiled coffee, in particular, appeared to raise total and low-density lipoprotein cholesterol and apolipoprotein B, while no similar effects were observed for filtered coffee. One study indicated a significant increase in blood interleukin 6 levels among individuals who consumed caffeinated coffee compared to those consuming no coffee.

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Insights

Coffee consumption, particularly boiled coffee, may increase levels of certain cardiovascular risk markers, but no strong link was found to anti-inflammatory effects.

Methodically considering pre-selected databases such as PubMed, Embase, CINAHL and more, this study rigorously searched for randomized controlled trials to analyse the impacts of coffee consumption on inflammatory indicators of cardiovascular risk. Duplicate data and trials that did not meet the study's criteria were removed. The remaining 17 studies that passed scrutiny were included in the analysis, looking particularly at effects of coffee on cholesterol levels, apolipoprotein B levels and interleukin 6 levels. This comprehensive review resulted in interesting findings. Boiled coffee emerged as a potential culprit for increased levels of total and low-density lipoprotein cholesterol along with apolipoprotein B. Filtered coffee, on the other hand, did not show similar trends. In one trial, caffeinated coffee showed a noteworthy increase in blood interleukin 6 levels compared to participants who did not consume coffee. However, no robust anti-inflammatory effects connected to coffee consumption could be confidently ascertained to be a significant factor in reducing mortality rates related to cardiovascular disease.