Otherwise known as the “nectar of the gods”, black coffee has long been associated with improved energy, sharpened focus, and increased performance. After all, when you’re tired or experiencing a mid-day slump, a cup of joe may be just the thing you need to power through. Yet evidence suggests that coffee’s health benefits go far beyond a boost of energy; it may even reduce your risk of chronic disease and positively impact your lifespan.
Before we examine what science has to say about coffee and longevity, let’s first understand caffeine’s impact on the body and how much you should consume each day.
What is caffeine?
Caffeine is a powerful stimulant that has been shown to increase alertness and wakefulness, decrease fatigue, and boost cognitive performance [1,2]. It works by blocking adenosine, a neurotransmitter that causes drowsiness. When caffeine binds to adenosine receptors, neuron firing and alertness increase along with adrenaline production. This cascade of effects is what helps you feel more energized, awake, and alert.
You can find caffeine in coffee, tea, energy drinks, and supplements, with coffee being the most popular choice. Recent survey data shows that coffee consumption has hit a two-decade high, with 66% of Americans drinking the brew each day [3].
How much is 200 mg of caffeine?
While you can find caffeine in a variety of sources, the highest content includes coffee. An 8-ounce cup of coffee provides 95-200 mg of caffeine. However, caffeine content in beverages can vary significantly from cup to cup depending on the variety, roast, and brewing technique [4].
Caffeine can also be consumed in certain food and beverage products--including energy drinks, gels, chews, gum, and bars--and is naturally present in kola nuts (used to flavor cola soft drinks) and cacao pods (used to make chocolate). Here are some other examples of caffeinated foods and beverages:
8-ounce black tea: 25-110 mg
12-ounce can of cola: 35-47 mg
12-ounce energy drink: 100-115 mg
1-ounce of dark or milk chocolate: 12-24 mg
Caffeine supplements: 2 mg/kg of body weight
Up to 400 mg of caffeine/day (roughly about 3-5 cups of coffee) is considered safe. However, caffeine is a stimulant and ideally, should be consumed earlier in the day to minimize potential sleep disturbances.
Caffeine's most common side effects include restlessness and shakiness, insomnia, headaches, dizziness, rapid heart rate, dehydration, anxiety, and dependency [31]. Additionally, studies show that regularly consuming more than 600 mg of caffeine/day may lead to stomach problems and high blood pressure [31].

Coffee and longevity
Studies show that your morning cup of joe may do more for your health than just getting you out of bed.
Not only does coffee tantalize your taste buds, but it’s also teeming with antioxidants, which have been shown to help neutralize free radicals, prevent oxidative stress, and protect against aging and other diseases [5]. As such, research suggests that a moderate consumption of black coffee can reduce the risk of chronic disease, delay age-associated pathology, and even extend your life [6]. Let’s examine these health benefits in more detail.
Reduced risk of type 2 diabetes.
Coffee’s antioxidant and caffeine content has been found to positively affect insulin sensitivity, inflammation, and metabolism [7,8,9]. Furthermore, each additional cup of coffee per day may reduce the risk of developing type 2 diabetes by 6% [7,8,9].
Supports brain health.
Coffee has been linked with a lower risk of dementia and cognitive decline, and could help protect against Alzheimer’s and Parkinson’s [10]. Additionally, studies have shown that regular caffeine consumption may slow the progression of Parkinson’s disease [11].
Promotes weight management.
Consuming up to 4 cups of coffee per day may positively impact the number on the scale. In addition, research indicates that it could decrease body fat and support gut health, both of which play a role in weight management [12,13]. Studies have also found that those who consumed up to 2 cups of coffee/day were 17% more likely to meet their physical activity and lose weight compared to those who had less than 1 cup of coffee/day [14].
Supports heart health.
Studies suggest that coffee has a positive effect on heart health. People who drink 3 - 5 cups of coffee/day have been shown to have 15% and 21% reduced risk of heart disease and stroke, respectively [15,16].
Improved mental health.
Coffee has been associated with improved mental health. Research indicates that people who drink at least 4 cups of coffee/day have a 20% and 53% lower risk of depression and suicide, respectively, compared to people who consume only one cup of coffee/day [17,18,19].
Reduced risk of early death.
Several studies have shown that people who drank 4-5 cups of black coffee/day had a 12% - 16% reduced risk of an early death, compared to the 6% lowered mortality risk of drinking one cup/day [20,21].
However, you can have too much of a good thing. Consuming more than 6 cups of coffee/day is associated with an increased risk of mortality [28].

Genetics and caffeine metabolism
Moderate coffee consumption has been inversely associated with mortality, but do your genetics also play a role?
Research indicates that the CYP1A2 gene is responsible for caffeine metabolism in the liver, with a single nucleotide polymorphism (SNP) from this gene helping to determine how quickly you metabolize caffeine [22]. For instance, studies show that the C allele of this SNP is responsible for slow caffeine metabolism, so if you have this variant, then your body will metabolize caffeine at a slower rate compared to people without the C allele.
If you’re wondering what camp you fall into, research shows you have a 50/50 chance of having a variant in the CYP1A2 gene [32]. To determine this, go based on how you feel after drinking coffee. Those who slowly metabolize caffeine often experience jitters and can be alert for up to nine hours. Conversely, fast metabolizers simply feel energetic for a few hours before needing another hit.
Interestingly, there has been an association between slower caffeine metabolism rate and an increased risk of impaired fasting glucose, hypertension and myocardial infarction (heart attack) compared to those who metabolize caffeine at a faster rate [22,23,24]. However, more research is needed to determine overall mortality rates based on caffeine metabolism.
Can coffee decrease your lifespan?
Despite the many health benefits of coffee, this well-loved beverage can come with some warning labels if you’re not careful.
Many specialty drinks are high in calories and refined sugar, both of which significantly outrank coffee’s antioxidant benefits and can quickly turn it into a nutrition bomb. For instance, a regular medium-sized mocha contains 35 g of added sugar, whereas a white chocolate mocha of the same size boasts a whopping 53 g of added sugar [25]. This sugar content quickly adds up, and even exceeds the added sugar guidelines from the American Heart Association, which recommend no more than 36 g and 25 g/day for men and women, respectively [26].
This surplus is a risk factor for many chronic diseases (such as heart disease, dementia, cancer, obesity, and type 2 diabetes), all of which can negatively impact your health and may even take a few years off your life [27].
That said, consuming a small to moderate amount of unsweetened coffee appears to have a positive impact on chronic disease risk for many and in doing so, may help improve longevity.
Decaf vs. regular coffee
Even though many people enjoy their morning cup of joe, there may be reasons that you decide to cut back on the caffeine and try decaf instead. But, other than the caffeine content, is there a difference in health benefits with decaf vs. regular coffee?
Science says no. A 6-ounce mug of decaf coffee provides 0-7 mg/caffeine, but without sacrificing any of the important antioxidants that come with regular coffee [29]. As such, you can still enjoy the taste of coffee and reap the benefits without any of the jitters.
Who shouldn’t drink coffee?
Caffeine can increase the risk of certain health complications, so lower intakes are recommended for pregnant women (0-200 mg/day) and individuals with anxiety, heart disease, diabetes, and seizures [30].
If you fall into any of these categories, talk with your healthcare provider to see if caffeine is right for you, and how much (if any) is recommended.
Summary
Coffee is a well-loved beverage that has long been associated with improved energy, sharpened focus, and increased performance, but emerging research shows that it can also extend your life. From improved brain health to a reduced risk of heart disease and type 2 diabetes, black coffee has numerous antioxidant benefits that greatly benefit health and reduce the risk of all-cause mortality. However, caffeine does have some negative side effects and is not recommended for everyone, so if you’re pregnant, have anxiety, or metabolize caffeine at a slower rate, it’s recommended to talk with your healthcare provider to see how much (if any) is right for you. Furthermore, the benefits seem to top out around 400 mg of caffeine per day, so there’s no need to go overboard to reap benefits.
Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose or replace personalized medical care.
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