Coffee gets a bad rep and is considered tea’s unhealthier cousin. It has more caffeine, fewer antioxidants, and studies suggest that excessive consumption can lead to an early demise.

It’s all pretty scary stuff, but it’s also nonsense, for the most part. For every negative study, there is a positive one that turns that fear-mongering on its head, and for every expert who declares coffee consumption to be an unhealthy habit, there is one who insists it will help you live longer.

The truth is somewhere in the middle: it’s not rotting you from the inside out, but it’s also probably not a life-saving, life-extending elixir. There are many ways in which coffee consumption could improve your health, but there are also some negative effects you need to watch out for.

Benefits and Side Effects of Coffee

Before we get to the benefits, let’s get the bad stuff out of the way.

• Caffeine Overdose: Coffee is high in caffeine, much more so than tea. Excessive caffeine consumption can lead to nervousness, agitation, sleeplessness, and nausea. In extreme cases, caffeine overdose can cause heart attacks and death, although it should be noted that most extreme reactions have resulted from energy drink and caffeine tablet/powder abuse.
• Cholesterol: Consumption of unfiltered coffee can increase the level of LDL cholesterol—a.k.a. “bad cholesterol”—and blood triglycerides, which can increase the risk of coronary heart disease.
• Miscarriage: Coffee is considered “probably safe” during pregnancy, but only in amounts of 2 cups or fewer per day. Anything greater than this may increase the risk of miscarriage and other complications.
• It May Exacerbate Certain Conditions: There are some concerns that coffee consumption can increase the risk of heart disease, anxiety disorders, bleeding disorders, diabetes, and bowel disorders in people who are susceptible to such conditions or already suffering from them. There is no proof that it can lead to such conditions in healthy individuals.

Can Coffee Increase Risk of Death?

A number of studies have found links between coffee consumption and an increased risk of death. One study, conducted by Dr. Carl Lavie on more than 40,000 adults found that 4 or more cups of coffee a day were associated with a higher mortality rate. (1)

But as alarming as this is, it’s important to understand that just because excessive coffee drinkers had a higher rate of death, it doesn’t mean that the coffee itself was at fault. In this study, the causes of death were not recorded and adjustments were not made for dietary habits or lifestyle choices.

It’s correlation versus causation, and while this can be a good tool to measure just how beneficial or harmful a substance is, it doesn’t quite paint a whole picture. However, considering just how much greater the risk of death was in those who consumed significant amounts of coffee a day (between 50% and 55%), it’s a warning to all coffee consumers to avoid drinking to excess.

As we shall discover, there are many studies out there showing coffee consumption to be beneficial, but these studies looked at small to moderate consumption, and once you enter into the “excessive” range, the results change for the worse.

Health Benefits of Coffee

The side effects mentioned above can be alarming if you drink coffee every day, but it seems that moderate consumption can be very good for you, as the following benefits show.

As with the mortality study linked above, many of these lack causation, but they are notable nonetheless.

1. Coffee May Help Reduce Neurological Conditions

Many positive studies name drinks and foods that may have the ability to reduce the risk of Parkinson’s, Alzheimer’s, and other neurodegenerative conditions. Sideritis Scardica is one of them, and one we have discussed extensively, but coffee is another, and one that is far more common in the general population.

One study found that both tea and coffee could help reduce the risk of Parkinson’s considerably, with another suggesting that the caffeine in these drinks could be the determining factor. (2) (3) This stimulant was also found to have a “protective” effect against Alzheimer’s, reducing the risk significantly in both male and female drinkers. (4)

2. Coffee May Help Protect the Liver

A study conducted in 2006 found an inverse association between coffee consumption and liver cirrhosis, which basically means that people who drink several cups of coffee a day were found to have a reduced rate of liver cirrhosis. (5)

They found that it could help offset some of the damage caused by excessive alcohol consumption but not enough to cure or reverse the effects. More research is needed before we know for sure if it has a similar effect on other liver conditions and if it can help support a healthy liver.

3. Coffee Probably Doesn’t Increase the Risk of Coronary Heart Disease

Some believe coffee consumption increases the risk of coronary heart disease. We touched on this above when discussing side effects, suggesting it is the result of drinking unfiltered coffee to excess, but the belief is that all coffee in all amounts can cause heart disease.

The truth is, we can’t say with absolute certainty that it does not, but there are many more studies that say coffee has no effect on CHD than there are studies that suggest it does. One significant meta-analysis found there to be no link between coffee consumption and heart disease and another found that coffee may actually have some preventative benefits. (6) (7)

Of course, you should still avoid drinking it to excess and you should be cautious if you have a history of heart disease, because caffeine is a stimulant. You should also make sure that you filter your coffee.

4. Coffee Consumption May Prolong Your Life

The tabloids love to declare that a popular food or drink may be killing us, almost as much as they love to tell us that it could prolong our lives. They switch between the two quite freely, and during our research, we found one newspaper focusing on a negative study just two weeks before publishing a positive one.

It speaks for how these studies are conducted, but it speaks more for how the tabloids choose to translate them. The good news for coffee drinkers is that there are more “positive” studies than “negative” ones, and when you reduce the parameters to minimal or moderate coffee consumption, the positive far outweighs the negative.

One of the largest studies looked at more than 41,000 men and 86,000 women over an 18-year period and made adjustments for age, smoking, and risk factors associated with cardiovascular disease. (8) It found that regular coffee consumption was not associated with an increased mortality in either sex and was actually connected to reduced rates of heart disease and cancer.

Again, this does not mean that coffee consumption will definitely prolong your life, but it makes for better reading if you are a coffee drinker, and judging by the common consensus, it also seems to have more of a basis in truth.