How moderate coffee consumption reduces cardiovascular disease risk

A comprehensive review highlights the complex relationship between coffee consumption and cardiovascular disease, exploring potential health benefits, bioactive compounds, and the need for further research.

Study: Coffee and cardiovascular health: a review of the literature. Image Credit: Natasha Kovtun / Shutterstock.com

In a recent review published in Nutrients, researchers examine the impact of coffee intake on cardiovascular disease (CVD).

Rises in cardiovascular disease

CVD is the leading cause of mortality globally, as it is responsible for over 17 million deaths each year. By 2030, researchers estimate that up to 23.6 million deaths will be attributed to CVDs.

CVDs comprise numerous conditions, some of which include aortic disease, stroke, and coronary heart disease. Several factors may increase the risk of developing CVDs, some of which include lifestyle factors like an unhealthy diet, smoking, and sedentary behavior, as well as health conditions like hypertension, dyslipidemia, obesity, and high cholesterol.

Diet plays a significant role in preventing and managing CVDs. Healthy eating patterns, like the Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets, both of which involve the high intake of fruits, vegetables, whole grains, healthy fats, and lean proteins, have been shown to improve lipid profiles, lower blood pressure, reduce inflammation, and reduce the risk of CVDs.

Benefits of coffee

Recent research has indicated that coffee is associated with numerous health benefits, of which include a reduced risk of mortality and developing CVDs, as well as improved cardiovascular health. Despite these observations, it remains unclear whether these effects are provided by both caffeinated and decaffeinated coffee.

Several studies have also reported that coffee intake can lower blood pressure; however, this relationship is complex. For example, certain studies have identified non-linear effects, with moderate intake of three to five cups every day appearing to provide the most benefits, whereas very low or high intake may have no benefit or even harmful effects.

Previous randomized control trials (RCTs) have investigated the impacts of coffee on CVDs; however, many of these studies have focused on individual components like caffeine. Additional limitations of these studies include their small sample sizes and varying methods, thus preventing researchers from determining definitive conclusions. Furthermore, whereas some trials showed no impact, others have observed increased blood pressure or reductions in blood lipids.

Potential underlying mechanisms

Coffee is a complex beverage containing various bioactive compounds, which can affect health in multiple ways. Although most studies have focused on the cardiovascular effects of caffeine in coffee, many other compounds, such as chlorogenic acids (CGAs), diterpenes, and trigonelline, may also be involved in this activity.

CGAs are polyphenols with potential cardiovascular benefits, including reduced blood pressure and improved arterial function. Although CGAs have low bioavailability, their effects may be mediated through nitric oxide pathways or gut microbiota modulation.

Diterpenes such as Cafestol and Kahweol are primarily found in unfiltered coffee and can raise cholesterol levels. For example, Cafestol may influence cholesterol metabolism by affecting the activity of low-density lipoprotein (LDL) receptors. Trigonelline, which is present in lower quantities, has antioxidant properties and may positively impact heart health.

The concentration of bioactive compounds in coffee varies based on factors like the coffee bean variety, the most common of which include arabica or robusta, growing conditions such as altitude and sunlight, as well as preparation methods such as brewing time, temperature, and filtration. For example, robusta beans contain more caffeine and CGAs than arabica beans, whereas coffee grown at higher altitudes generally has more CGAs.

Commercial processes such as roasting and decaffeination also influence the levels of bioactive compounds. Roasting reduces CGAs and trigonelline, though caffeine levels remain stable. The method of brewing, such as using espresso or boiling coffee, can also affect the extraction of compounds like diterpenes and caffeine.

Caffeine, the most studied bioactive in coffee, is metabolized in the liver, and its effects on cardiovascular health are debated. Although moderate caffeine consumption is generally considered safe and may not increase the risk of heart disease, it can raise blood pressure levels in the short term, especially in sensitive individuals. However, regular consumption may not have sustained effects on blood pressure or cardiovascular risk.

Conclusions

Overall, the health effects of coffee are complex and depend on various factors, thus making it challenging to draw definitive conclusions about its impact on cardiovascular health. Although observational evidence supports moderate coffee intake for maintaining cardiovascular health, more rigorous and well-designed RCTs are needed to confirm causality, as well as clarify the effects of coffee on CVDs and the underlying mechanisms.