Is Coffee Bad For You? Four Surprising Research Findings

Is Coffee Bad For You? Four Surprising Research Findings

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There’s a significant amount of misinformation online about the healthiness (or lack thereof) of coffee. One day a study will come out suggesting that coffee is healthy, and the next day a conflicting study may come out suggesting the opposite.

But is coffee healthy or not based on clinical studies? What's the healthiest way to prepare coffee? Are popular coffee drinks like Starbucks lattes unhealthy? And is coffee bad for people with health conditions like high blood pressure?

In this article we’ll answer all of these questions and more, as we review clinical studies to share four surprising research findings on the health effects of coffee.

We'll explain the healthiest way to prepare coffee, feature an animated video highlighting some of the health benefits of coffee, and discuss why instant coffee may be the worst option available.

We'll also discuss whether coffee may be bad for certain individuals with pre-existing health conditions.

Four Surprising Research Findings

1) Coffee consumption is associated with longevity 

A 2013 medical review analyzed data from clinical trials on coffee and mortality, and concluded that coffee drinkers experienced reduced mortality from all causes and reduced incidence of cardiovascular disease.

2) Coffee consumption may reduce risk of developing diabetes

A 2008 medical review reported that coffee consumption modulates levels of gut peptides which regulate insulin levels.

Insulin regulates blood sugar levels, and the study authors proposed that for this reason, coffee may help prevent the development of type 2 diabetes.

3) Coffee consumption can improve workout performance

A meta-study published in the Sports Medicine journal found that caffeine, which is the predominant chemical compound in coffee, improves both power and muscular endurance during resistance training exercise.

4) Coffee consumption may reduce risk of depression

The potential health benefits of coffee are not limited to physical benefits, but also include mental benefits.

meta-study published in the Molecular Nutrition & Food Research journal analyzed data from over 300,000 individuals and found that those with higher coffee intakes were 24% less likely to suffer from depression.

What's the Healthiest Way to Drink Coffee?

We consider black coffee, which just means coffee brewed and prepared without anything added, to be the healthiest way to drink coffee.

Black coffee contains all of the antioxidants and phenolic compounds that give coffee its health benefits, including chlorogenic acid which is clinically shown to have anti-inflammatory and anti-obesity effects.

Black coffee also contains polyphenols which may have a neuroprotective effect and reduce the risk of stroke according to a 2020 medical review.

Essentially, black coffee contains all of the compounds which give coffee its health benefits, while commercial coffee products contain a number of questionable additive ingredients that may negate the health benefits of coffee and make the drink unhealthy overall.

We’ll provide an example in the next section of this article to highlight this distiction.

Starbucks Latte Ingredient Analysis

Starbucks Pumpkin Spice Latte ingredients

The ingredients in a Starbucks Pumpkin Spice Latte are shown above.

Sulfiting agents and potassium sorbate are synthetic preservatives, the latter of which has been clinically shown to negatively alter gene expression and contribute to inflammation as we documented in our review of Bang Energy drink.

Citric acid is a flavor enhancer shown to cause whole-body inflammatory reactions in some individuals, according to a report in the Toxicology Reports journal.

Natural flavors is an ingredient we recommend avoiding because it fails to describe the specific flavoring agents used, and there are documented toxicity concerns with some food flavoring agents and their metabolites.

This Starbucks latte is also high in calories and added sugar, as shown below:

Starbucks Pumpkin Spice Latte Nutrition Facts

Added sugar is positively associated with increased risk of cardiovascular disease according to a 2014 medical review, and this Starbucks drink provides 100% of the Daily Value (DV) of added sugar in one single serving.

We consider drinks like Starbucks Pumpkin Spice Latte to be bad for you, but not black coffee.

Coffee Benefits Animated

One of the most popular videos on the health benefits of black coffee has over 800,000 views, is only four minutes long, and comes from a YouTube creator named "TheHealthNerd":

Is Instant Coffee Unhealthy?

Acrylamide is a chemical compound produced when food products are heated at very high temperatures. Nearly all types of coffee contain acrylamide, but its levels are much higher in instant coffee than in regular roasted coffee.

A 2013 clinical trial documented that instant coffee has acrylamide levels twice as high as regular coffee. The same trial reports that acrylamide is neurotoxic and carcinogenic (cancer-causing), according to animal studies.

The health benefits of coffee likely outweigh the potential downsides of acrylamide intake, even for those consuming instant coffee, but it seems logical to choose regular roasted coffee (or whole beans) instead of instant coffee to reduce this risk.

Instant coffee is often considered to be cheaper, but when purchased in bulk, prices can be nearly equivalent.

Is Coffee Bad for Some People?

While coffee appears to be a net-positive choice for already healthy people, there are some conditions that may make its intake a riskier choice.

Caffeine is known to increase blood pressure, and can increase systolic blood pressure by an average of 8.1 mm Hg according to a clinical trial.

This may make decaffeinated coffee, or tea, a better choice for individuals with high blood pressure.

Coffee may also be inadvisable for people prone to anxiety because it can increase adrenaline and stress.

A 2004 medical review found that coffee can cause anxiety symptoms even in individuals without anxiety, but especially in those with anxiety disorders.

Caffeine is a stimulant that can trigger the “fight or flight” response due to the release of adrenaline, so it may be best for those prone to anxiety to avoid coffee altogether.

We would recommend that individuals with high blood pressure or anxiety speak with their doctor about whether coffee is safe for them or not.

Our Clean Coffee Picks

MBG Clean Coffee+ is our top coffee product, because it’s ground for convenience, organic certified, and third-party lab tested for purity (which is highly uncommon for coffee).

Four Sigmatic Think is our top nootropic coffee brand, because it contains organic Lion's Mane which is clinically shown to enhance cognitive function.

Both of the products recommended in this section are entirely free of additive ingredients that we consider to be unhealthy.

Stay up-to-date on our research reviews


Coffee is not bad for you if it’s consumed as black coffee. We consider black coffee to be healthy for most people based on research studies.

In this article, we cited research suggesting that coffee consumption may increase longevity, reduce the risk of developing diabetes, improve exercise performance, and reduce the risk of depression.

We consider popular, sweetened coffee drinks like Starbucks Pumpkin Spice Latte  to be unhealthy due to the inclusion of preservatives, significant quantities of added sugar and other questionable additive ingredients.

Regular roasted coffee is a healthier choice than instant coffee due to the lower acrylamide levels, though we would not consider black coffee made from instant coffee bad for you overall.

Individuals with high blood pressure or anxiety should speak with their doctor about whether or not coffee consumption is safe for them.