There is a long-standing debate in the wellness community over whether coffee is “good for you” or “bad for you”. A link between coffee and liver health may help to tip the scales.
The problem with that debate topic is not the coffee. The problem is that “good” and “bad” are nonspecific, while “you” is uniquely specific.
Coffee may be bad for you if you are allergic or highly sensitive to caffeine. Coffee may be bad for you if you are filling it up with sugar, sugar substitutes, or highly processed, chemically-flavored creamers.
But, coffee consumption has also been associated with a reduced incidence of various chronic diseases such as diabetes, cardiovascular diseases, mood disorders, and neurodegenerative diseases [1]. In terms of your body’s favorite detox organ, specifically, it looks like there is a positive link between coffee and liver health.
If you like coffee, this is all good news.
Is coffee good for your liver?
Signs point to “yes”, and this is not new news. Over the last 30 years, several discoveries have been made linking coffee and liver health.
In 1992 a relationship between coffee drinking and a reduced risk of cirrhosis was first reported [2]. Since then, coffee drinking has also been shown to reduce the risk of developing significant chronic liver disease [3]. Other studies have demonstrated that coffee drinkers express lower levels of multiple markers of liver disease, providing a reasonable basis for hypotheses that coffee may provide hepatic protection.
The mechanisms behind the protective effects are still under investigation. Recently, however, a very large study showed that coffee drinking was associated with lower liver stiffness [4]. Liver stiffness is a marker of liver health, as fibrosis (an over-accumulation of structural proteins) causes a stiffening of the liver. Fibrosis is the precursor to cirrhosis and liver failure [4]. If coffee does prevent fibrosis, it would follow that coffee drinkers would have a lower risk for liver disease and cirrhosis.
It is important to note that the same group that published this finding on coffee and liver stiffness, also reported an opposite relationship between sugary-beverage consumption and liver stiffness [5]. Let this be your cue to find a natural, unsweetened creamer you enjoy or practice drinking your coffee black.
Does coffee benefit other aspects of human health?
Brain & Mood
Coffee and liver health is a boon, but coffee (in moderation) may also be good for your brain. Aside from caffeine, coffee is made up of polyphenols and other antioxidants whose jobs are cellular repair and the prevention of oxidative damage.
This may be the reason that regular, habitual coffee drinking has been associated with a lower incidence of dementia and other degenerative diseases [6]. However, there is a limit to its benefit. Data from the UK revealed that the risk of developing dementia rose again for those who drank more than 6 cups a day [7].
There is a sweet spot for coffee’s effect on depression too. There is a significant decrease in the risk of depression for those that consume 68-509 mg of caffeine per day [8]. That means the risk is higher for those that drink less than half a cup, or more than 4 cups, of caffeinated coffee.
A Finnish study showed that the risk of death by suicide also decreased with increased coffee consumption, up to 6 cups of coffee per day [9]. After 6 cups a day, the risk starts to increase again.
What about coffee might be supporting a healthier mood?
If these findings intrigue you, you’re probably curious about how it works.
Caffeine plays a role in the transmission of dopamine, through its antagonistic action on the adenosine A2A receptor in the brain. It may also, through the same mechanism, modulate the release of acetylcholine and serotonin [10].
When ingested in moderation, caffeine has psychostimulant effects, like improved psychomotor performance, increased vigilance, elevated arousal, and an increased sensation of energized wellbeing [10]. While the effects of caffeine are dose-dependent, they are also typically biphasic. This means that low to moderate doses feel pleasant and stimulating, but once an individual’s tolerance threshold has been crossed, they begin to feel opposite effects [10].
While the tolerance point for caffeine may grow over time, it is different and unique in every person. Generally, mood studies show that 1-4 cups is a safe zone for most people. You may want to consider that data when you go to pour cup number 5…
Insulin/Glucose Balance
Antioxidants in coffee may improve glucose metabolism and insulin sensitivity [6]. Interestingly, acute administration of caffeine (e.g. giving coffee to a non-coffee drinker) can induce insulin resistance and impaired glucose tolerance, but when consumption of coffee is regular over a long period of time, it is then associated with improved insulin sensitivity and better control of glucose after a meal in patients with type II diabetes [6].
Apparently, drinking five cups of coffee per day increases adiponectin (which decreases insulin resistance), compared to no coffee [6]. Caffeine can actually activate insulin-sensitive glucose transport in skeletal muscle [6]. This means muscle cells actually get more sugar to make energy when caffeine is present.
An animal model was used to demonstrate that long-term caffeine consumption enhances insulin sensitivity as well as insulin secretion [6].
Does coffee have any negative effects in the body?
Caffeine can have toxic effects if consumed in excessive quantities, but you might have to drink 50-100 cups of coffee in a row to die from it. Ten cups of coffee would likely leave you feeling dehydrated, shaky, and nauseous.
Participants in one recent study, who consumed >400 mg/day of caffeine showed a double-high risk for headaches, feelings of panic, worrying too much, and experiencing feelings of worthlessness [11]. For reference, one 8 ounce cup of coffee contains an average of 150 mg of caffeine, so these participants have three or more cups of coffee daily.
Both caffeine and non-caffeine components of coffee have been shown to temporarily increase blood pressure in non-habitual coffee drinkers [6]. The tolerance for these compounds quickly increases, and they do not affect the blood pressure of those who drink coffee regularly.
If you are pregnant, too much caffeinated coffee can lead to negative gestational outcomes, including pregnancy loss [12]. The mechanism behind this effect is still in question, and again, there is a threshold and it is unique to each mother. Some women are not as sensitive to caffeine as others naturally, and some have built a tolerance prior to pregnancy that provides a protective effect for the fetus [12].
Because of this, some studies question the existence of a “safe” gestational dose currently set at 300 mg/day (approximately 2 cups of coffee) [12]. This may be safe for people who drank more than 2 cups daily before pregnancy. We wouldn’t recommend it to those who were not coffee drinkers before pregnancy. A switch to decaf during pregnancy may be a safer bet.
I don’t like coffee. What else could I do to support my liver health?
There are many healthy choices you can make to boost your liver health without starting a new coffee habit.
Drinking enough water is very important, as the filtration of toxins through the liver and kidneys is dependent on water.
Silymarin is an extract of milk thistle (Silybum marianum), and the most common supplement taken to support healthy liver function [13]. This extract expresses membrane-stabilizing and antioxidant activities, promotes hepatocyte regeneration (growth of new liver cells), reduces inflammatory reactions, and inhibits fibrogenesis [13]. Silymarin extract may also reduce the toxic effects of other drugs [13].
If you are interested in a liver-supportive morning drink to replace coffee (and breakfast), Metabolic Maintenance’s Metabolic Detox Complete provides a daily multivitamin/mineral complex, plus silymarin, in a naturally flavored shake powder.
ALA
Alpha lipoic acid (ALA) and N-acetyl-cysteine (NAC) are two more great nutrients to supplement with for liver health, as they are both naturally occurring thiol antioxidants that play many, diverse biological roles.
ALA is a potent antioxidant, a detoxification agent, and a regulator of inflammation [14]. It also decreases the storage of fat in the liver [15]. ALA is an amphipathic molecule meaning its antioxidant effects can take place both in hydrophilic (inside cells or blood) and lipophilic (inside cell membranes or fat cells) environments and has been shown to provide benefits in liver disease models [16].
NAC
N-acetyl-cysteine (NAC) consistently inhibits apoptosis and interferes with oxidative stress pathways [17]. NAC is also a precursor for glutathione synthesis and plays a role in its regulation.
Glutathione, the body’s “master antioxidant,” is essential for a healthy liver for a variety of reasons. Glutathione scavenges free radicals and other reactive oxygen species; it reacts with various electrophiles, physiological metabolites (e.g. estrogen, melanins, prostaglandins, and leukotrienes), and xenobiotics (e.g. bromobenzene and acetaminophen) to form mercapturates; it regulates cellular lipid, glucose, and amino acid utilization; and aids in the removal of toxins like formaldehyde from cells [18].
Metabolic Maintenance’s Metabolic Detox capsules contain all of the above.
Back to Nutrition AlertA safer bet for pregnancy is switching to decaf