I was never much of a coffee drinker in years past. Much of my hesitation stemmed from the negative — and often unproven — claims linking coffee consumption to poor health. Over time, however, as the research evolved, so did my perspective. Today, coffee has earned a modest place among my preferred hot beverages, enjoyed in moderation and with intention.

Botanically, coffee belongs to the Rubiaceae family and the genus Coffea (Eira et al., 2006). Plants within this family are known for their physiological effects, particularly on the nervous system. This is largely due to caffeine — one of coffee’s primary bioactive compounds — which acts as a central nervous system stimulant (Sciencedirect.com; Belitz et al., 2009).

More than 70 species exist within the Coffea genus, yet only two are widely cultivated for global consumption: Coffea arabica (Arabica) and Coffea canephora (commonly known as Robusta). Arabica accounts for the majority of worldwide consumption and is prized for its smoother flavour profile. Robusta, on the other hand, contains significantly more caffeine and is frequently used in blends and instant coffee production (Davis et al., 2019).

Despite its widespread popularity, coffee remains controversial — primarily because of its caffeine content. However, the narrative surrounding coffee is shifting. A growing body of scientific evidence suggests that moderate coffee consumption may offer several health benefits, particularly in relation to cardiovascular health.  Let’s discuss!

What is Coffee?

Coffee is a brewed beverage made from the roasted and ground seeds (commonly called beans) of the Coffea plant. These seeds develop inside the fruit of the plant, known as coffee cherries. The coffee fruit consists of a smooth yet firm outer skin that changes from green to deep red or red-violet when ripe (Belitz et al., 2009; Purseglove, 1974).

Internationally, coffee is typically traded as green coffee, referring to the raw, unroasted beans. These beans may still contain the thin protective layer known as the silver skin, which covers the endosperm and is largely removed during roasting (Belitz et al., 2009; Klingel et al., 2020).

Globally, coffee is consumed by millions of people daily and is often described as a functional beverage because of its potential role in reducing the risk of certain chronic diseases (Esquivel & Jiménez, 2012). However, its health effects depend significantly on the composition of the beans and the degree of roasting, both of which influence its bioactive compounds (Belitz et al., 2009).

Most of the coffee consumed globally reportedly comes from two (2) primary species – Coffea arabica (Arabica) species and Coffea canephora (Robusta) (Patay et al. 2016).  Arabica coffee generally has less caffeine than Robusta and is traded more expensively on the international market due to its more distinct properties (Barone and Roberts, 1996; Bertrand et al., 2003).

When coffee is brewed, it is described as a stimulant, which is due mainly to its caffeine content. However, other compounds have caused it to garner the name of being a functional beverage.  Some of the other profound compounds of coffee include its polyphenols (i.e. chlorogenic acid, flavonols and anthocyanidins (George and Ramalakshmi, 2008), anthocyanidins (Ramírez-Coronel et al., 2004), as well as antioxidants, phytonutrients, and key enzymes (Heimbach et al., 2010).  Coffee has also been shown to have antiviral activity (Utsunomiya et al. 2008).

These and many other compounds have contributed to the beneficial effects of coffee on the body, such as having a positive effect on the cardiovascular system, diabetes risk, and liver disease risk, among others (Nieber, 2017).

Some of the purported nutrients in coffee include niacin (vitamin B3), magnesium, potassium, and vitamin E (USDA Nutrient Database, 2004).  Additionally, according to the same nutrient database, an 8-oz cup of brewed coffee provides about seven (7) mg of magnesium and one hundred and sixteen (116) mg of potassium (http://www.nal.usda.gov/fnic/foodcomp), which can help contribute to our daily intake of these nutrients.  Coffee reportedly also has many functional properties such as flavonoids, ferulic acid and caffeic acid (Meletis, 2006).  It also possesses antioxidant properties (Rufian-Henares et al 2007, etc.).

In this article, we will be exploring five (5) proven health benefits of consuming coffee as well as its main bioactive compound – caffeine.  The five benefits to be discussed are – its effects on the cardiovascular system, diabetes risk, and its protective effects on the liver.  We will also look at its benefits to the neurological system, especially as it relates to nervous system disorders.  The post will also explore some of the reported side effects of consuming coffee.

 Five (5) Health Benefits of Consuming Coffee:

• Caffeine Properties
• Cardiovascular Health
• Diabetes Risk
• Liver Health Risk
• Parkinson’s Disease Risk

Coffee and Caffeine Properties

Caffeine is one of the most investigated and controversial compounds of coffee.  But is it a bad thing? Well, many reports would indicate – No!  Caffeine is the main alkaloid that naturally occurs in coffee beans (James, 2004).  It accounts for up to four (4%) percent of the dry beans.  However, the percentage will vary depending on the agricultural practices (Belitz et al. 2009; Dessalegn et al. 2008, etc.). It is also what contributes to the bitterness of coffee (Farah et al. 2006).

When an individual consumes coffee, it first goes to the stomach and then the small intestines, ending up in the brain and other tissues of the body (Higdon and Frei, 2006).  Additionally, because coffee is a stimulant, its consumption may lead to general alertness, stimulation of the central nervous system, a rise in blood pressure and increased urination (diuretic) (Carrillo and Benitez, 2000; Belitz et al., 2009; Reich et al., 2008).

Caffeine may also enhance one’s mood and exercise routine. Reports also purport that it may reduce some of the symptoms associated with Parkinson’s disease (Heckman et al. 2010).  Caffeine has also been associated with some negative effects, such as causing one to feel drowsy (sleepiness) as well as being addictive (DuFrene and Rubinstein, 2010).

However, most of the controversial side effects of coffee have been associated with high doses of caffeine, which can cause anxiety, restlessness, nervousness, etc. (Daly and Fredholm, 1998). Further, some research purports that long-term consumption may increase one’s risk of cardiovascular disease (Yang et al. 2010).   Nonetheless, other studies have denoted otherwise.

High consumption of coffee, based on most research, is anywhere from six (6) cups or more per day. However, research has shown that this was not associated with a higher or lower risk of cardiovascular disease (Ding et al. 2014).   Additionally, four (4) cups per day were purportedly associated with an increased risk of mortality, but only for persons under fifty-five (55) years old (Liu et al. 2013).  Nonetheless, these effects cannot be denoted as definitive due to many purported factors such as brewing methods, individual genetics and even the diet and lifestyle of people in general.

It must be noted that coffee is not the only beverage that contains caffeine.  As such, one must be aware of the others which have proliferated our grocery aisles.  For example, teas may have upwards of twenty-eight (28) mg depending on where they are sourced or grown, sodas (soft drinks) may have around forty (40) mg, energy drinks (80 mg), and beverages made with cocoa powder (6 mg) (International Food Information Council Foundation, IFIC review, 2017).

Coffee and Cardiovascular Health

As indicated earlier, there are mixed reviews as it relates to coffee and cardiovascular disease. However, most research purports that moderate consumption of coffee was associated with positive outcomes for cardiovascular health (Lepper MH. et al. 1963).  Several meta-analyses did not support the arguments of coffee consumption and higher incidences or risk of cardiovascular disease.  As such, the conclusion then was uncertain (Conti et al. 2007; Mostofsky et al. 2012).

On the other hand, a large study conducted in 2014 by Ding and Colleagues purported that moderate daily consumption of coffee was associated with a reduced risk of cardiovascular disease (Ding et al. 2014).  Moderate consumption of coffee, as per this study, refers to 3-5 cups per day. Interestingly, consuming more than six (6) cups of coffee per day was neutral, as it did not show a higher or lower risk of cardiovascular disease (Ding et al. 2014).  However, a cap was not mentioned as per the upper limit of coffee consumption daily.

Further studies also confirmed the findings of the 2014 study by Ding and colleagues. These studies did not find any association between heavy coffee consumption and cardiovascular risk (Malerba et al. 2013).  However, a study by Liu et al (2013) found that four (4) cups or more per day was more associated with mortality (death), but only for persons under fifty-five (55) years of age.

Nonetheless, the findings of some research remain contradictory, which has prompted researchers to note that no definitive results may be ascertained, as several factors must be taken into consideration when it comes to studies of this nature.  Factors such as brewing methods and dietary assessment.

  Further, research contends that currently, no clinical basis exists for the association between moderate coffee consumption and an increased risk of cardiovascular disease, including incidences of stroke (Kim et al. 2012).  To this extent, research purports that caffeine, as well as other compounds of coffee, may have a positive effect on the cardiovascular system, instead of a negative one.  Especially when it is consumed moderately.

Coffee and Diabetes Risk

Research has purported health benefits when it comes to the consumption of coffee and metabolic disorders such as type-2 diabetes. However, like cardiovascular disease risk, which in some research remains controversial, the same holds for diabetes.  This is because some studies have shown an inverse association between coffee consumption and metabolic disorders.  An inverse association means that when the value of one variable is high, then the other is low and vis-à-vis.

The major study in 2014 by Ding and colleagues with participants who had type-2 diabetes showed an inverse relationship between coffee consumption and the risk of type-2 diabetes when compared with no coffee consumption.  The number of cups mentioned in this study was six (6) cups per day.  The results showed a lower risk of developing type-2 diabetes, even with up to six (6) cups per day. These findings applied to both men and women.  However, the findings suggested that coffee had a more protective effect for women than men.  Nonetheless, these findings were based solely on self-reported dietary questionnaires and, as such, may have some biases and limitations.

Interestingly, further studies by Ding et al. (2014) also showed similar results with decaffeinated coffee. This is because it was shown to have the same protective effect against type-2 diabetes as caffeinated coffee.  These results differ somewhat from those of a European-based study, which purported lower incidences of type-2 diabetes for caffeinated coffee than decaffeinated coffee of four (4) or more cups per day (Floegel et al. 2012).

Therefore, the evidence is profound in these studies for an increase in insulin sensitivity for coffee consumption, whether it be caffeinated or decaffeinated (Loopstra-Masters et al. 2011).  The studies also purported that other compounds of coffee, for example, polyphenols, which are high in antioxidants, may also be a contributing factor to the positive effect of coffee consumption and the risk of type-2 diabetes (Bhupathiraju et al. 2013; Ong et. al. 2012).  As such, coffee has been mostly shown to have a protective effect against type-2 diabetes, not only due to the caffeine but also other active compounds.

Coffee and Liver Health

Coffee consumption may also have a positive effect on the liver, especially in persons suffering from liver diseases such as fibrosis, etc.  This was purported by several studies, one major one being a 2016 study by Wadhawan and Colleagues (Wadhawan et al. 2016).

The researchers concluded that the consumption of two (2) or more cups of coffee per day by people with preexisting liver disease showed a lower incidence of fibrosis and cirrhosis as well as decreased mortality from cirrhosis due to alcohol consumption (Klatsky and Armstrong, 1992; Tverdal and Skurtveit, 2003).  It must be noted that this result was also the conclusion for the meta-analysis by Liu et al. (2015), whose study was based on coffee consumption and hepatic fibrosis and cirrhosis.

This was also the finding of other studies, which concurred that the consumption of two (2) or more cups of coffee per day was associated with a lower risk of chronic liver disease when compared to people who did not consume coffee (Liu et al. 2013; Shim et al. 2013, etc.).  This may be due to the findings that the consumption of coffee was able to reduce the hardening of the liver, which would indicate a reduction in inflammation and fibrosis in persons with nonalcoholic fatty liver disease, as well as hepatitis B and C (Hodge et al. 2014).   

Hepatitis B and C reportedly cause inflammation of the liver (yalemedicine.org).  Further research also showed an inverse association between coffee consumption of more than four (4) cups per day and elevated levels of serum enzymes (Klatsky et al. 2006), especially in persons who were heavy alcohol drinkers.

However, some researchers have argued that these results may not only be due to the caffeine in coffee but also to other compounds, in this case, chlorogenic acid, cafestol and Kahweol (Xu et al. 2014; Shimamoto et al. 2013, etc.).   Nonetheless, in the case of liver disease, especially liver fibrosis and cirrhosis, chlorogenic acid, cafestol and kahweol have been highlighted as possible contributors to coffee’s positive effects on the liver.

According to research, chlorogenic acid reportedly has a hepatoprotective (prevents damage) effect on the liver (Wan et al. 2013).  In fact, in a study by Xu et al. (2014), it was found that chlorogenic acid was effective in suppressing induced oxidative stress and thus provides a hepatoprotective effect on the body.  The other two (2) highlighted compounds, cafestol and kahweol, may also provide a protective effect on certain factors that may cause liver damage (Furtado et al. 2012; Shim et al. 2013).  

Additionally, the researchers theorized that these compounds may also play a role in the detoxification and prevention of liver damage. To this extent, consistent research has shown a positive effect of coffee consumption on liver disease. Nonetheless, no concrete evidence has been presented as to the growth or progression of liver disease/s.

Coffee and Parkinson’s Disease Risk

Parkinson’s disease is a disorder that mainly affects the nervous system.  Research has shown that caffeine, not only from coffee but from other sources, has an inverse relationship with the risk of Parkinson’s disease (Hernan et al. 2002).  The positive effect of coffee and caffeine consumption was shown for both men and women.

In a study conducted in 2000, it was found that men who did not drink coffee were at a higher risk of developing Parkinson’s disease over the next Twenty-four to Thirty (24 -30) years than those who consume at least three (3) cups (28oz) daily (Ross et al. 2000).  However, in another study conducted in 2001, it was found that men who consume at least one cup of coffee regularly were at risk of developing Parkinson’s disease over the next ten (10) years than those who did not (Ascherio et al. 2001).

On the other hand, the risk of developing Parkinson’s disease for women was dependent on whether they had estrogen replacement therapy. In that, studies only found an inverse relationship for women who never had postmenopausal estrogen therapy. However, a heightened risk was observed for women who did have this therapy and had drunk at least six (6) cups of coffee per day (Ascherio et al. 2003).

As such, the researchers purport that estrogen may have a modifying effect on caffeine, especially as it relates to the risk of Parkinson’s disease.  Therefore, estrogen may work to prevent particular metabolism of caffeine, resulting in a higher risk threshold for post-menopausal women who have used estrogen (Pollock et al. 1999).

How much coffee can I drink daily?

A definite verdict is still out on the number of cups of coffee per day that may have absolute beneficial results, especially when it comes to disease prevention or progression.  However, most research has indicated moderate consumption is beneficial.  Moderate consumption in most cases was 3 – 5 cups per day.  Even up to six (6) cups per day was proven beneficial in some studies. 

Moderate consumption apparently may have a positive effect on the cardiovascular system and diabetes risk, among other diseases discussed in this article.  Nonetheless, most of these studies did not take factors such as brewing methods, cultivars, and dietary assessments, among others.  As such, like with all other foods that may have a positive effect on our health, moderation remains key.

Side Effects of Consuming Coffee

Some research has indicated controversial results as it relates to the mentioned diseases of this post – cardiovascular, liver, diabetes, and Parkinson’s, but not all of them.  Further, some people may benefit more than others when it comes to coffee consumption due to several factors such as gut bacteria, how they metabolize coffee, lifestyle (i.e. physically active or not) and overall diet.  Also, there is no definite amount that may prevent or slow the progression of any disease.

Further, the side effects of consuming coffee will vary from person to person. However, not all people will experience side effects from coffee, especially when consumed moderately. Nonetheless, reports have indicated anxiety, restiveness, nervousness, etc. (Daly and Fredholm, 1998).

Illustrative Summary

Here is an illustrative summary of the five (5) HEALTH BENEFITS of  CONSUMING COFFEE

Let’s Sum Up!

Coffee has been getting some good reviews over the last few years.  However, the controversy still exists, especially when it comes to its effects on some diseases, for example, cardiovascular disease and diabetes, among others.

Nonetheless, research has shown that it may have a protective effect on the cardiovascular system, the liver, and diabetes.  It may also have a positive effect where Parkinson’s disease is concerned, especially in moderate consumption, coupled with a healthy and active lifestyle. 

Notably, though, the development of some diseases may far exceed that of even a healthy diet or the consumption of coffee or other foods that may provide profound benefits to the body.  This is because other complex scenarios may play a role, such as one’s genetics, etc.  Nonetheless, the best we can do is practice a healthy diet and seek to incorporate foods that can positively impact our health while removing those that will hinder it.  As such, coffee might be a worthwhile addition.

However, in all things, moderation is the key, especially in the case of caffeine consumption, whether it be coffee or other caffeinated beverages.

So, now that we have explored coffee and some of its major compounds, is it a beverage that you consume? How many cups do you consume per day?  Share it nuh!

You can read more on caffeine and other nutrients in general in these articles:

• Iced Coffee – Dairy Free!
• It’s teatime – Here are four (4) ‘to know’ benefits of teas and a great way to store them.
• Burdock Root – another priceless gift of Nature – Here are Six (6) Reasons why!
• Let’s Talk Oolong Tea
• Pycnogenol and Diabetes – Is There a Positive Link?
• Video: Let’s Talk Coffee

This article was last updated by a Research Consultant and Certified Nutrition Coach on February 26, 2026.

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