Simply googling "is coffee good for you?" will present you with enough info and confliction to wanna blow your brains out (or "toss your computer out the window"), or just give up on your search for the answer.
Luckily, I'm here to save you and keep your sanity in check.
There's a lot to cover on this subject but I'm literally going to make it as straight up as possible for ya. You've got questions, I've got simple answers based on research (as always). I'd throw in anecdotal discoveries as well BUT everyone knows the clear acute effects of coffee consumption.
Here's what I'm going over:
Is coffee good/bad for you?
Potential Health Benefits
Proven Performance Benefits
Potential Negative Side Effects
Cautionary Measures and Dosages
5 Quick Points to learn all the basics of coffee and if YOU should be drinking it or not.
Is Coffee Good or Bad for You?
Many studies have cited potential positive benefits in terms of decease prevention. Specifically: heart disease, stroke, diabetes. Let's tell you how as opposed to just shouting out random things or resorting to massive meta-analysis studies where the issue of "correlation isn't causation" is far too abundant.
Diabetes: It may help reduce risk of diabetes due to coffee's antioxidants and minerals (such as magnesium and chromium) which have an effect on blood sugar control and insulin secretion. On the other end of the spectrum, more than enough research has shown that caffeine on its own can NEGATIVELY effect glucose uptake. So who's to say if coffee consumption really helps diabetes? Don't you think there are FAR better things you can do to manage (or even reverse) diabetes apart from simply drinking coffee?
Did anyone say "Healthy Diet And Exercise!"?
Heart Disease: The reasons for this are unknown but research shows that people who drink 1-3 cups of coffee a day have a (up to) 20% lower risk of heart disease. Specifically heart atttacks and heart abonormalities. This could have something to do with the caffeine in coffee which in some tissues act as a vasodilator (expands the veins) and others a vasoconstrictor (tightens the veins).
At the same time, people who suffer from heartbeat abnormalities and or anxiety may experience opposite effects with coffee. Find out more in the "Potential Negative Side Effects" paragraph.
Dementia and Parkinson's
Drinking coffee long term can be protective of the brain (probably due to antioxidants and caffeine) thus slightly reducing the risk of Dementia, Parkinson's and Alzheimer's.
Coffee has been shown to slightly decrease inflammation in the body. Having said that, I wouldn't ditch the fish oils for coffee, it's just a potential minor health benefit.
The Good Stuff
Let's get real for a second. Most of you want to hear 2 things in this article:
Is it going to help me lose fat or get jacked?
Please tell me something really good to justify my coffee addiction
Proven Performance Benefits
It's your lucky day, coffee consumption has been proven to improve performance in pretty much every quality of fitness you can think of!
Strength Gain (anaerobic): Like I stated above, the caffeine in coffee stimulates your nervous system and adrenaline. When that happens, your nervous system is awake, aware (maybe a bit on the edge) but ready to go and use the mind-muscle connection to its full potential. This means you'll be able to produce more force in an acute setting.
In other words: drink coffee = lift heavier, probably
Endurance Gains (aerobic): Coffee consumption pre long distance endurance training has improved trial time and mental focus.
Muscle Gain: Similar to the strength gains, you're able to produce more force therefore can create more muscular damage which can help stimulate muscle growth. Take a note from the endurance side as well, better endurance through longer sets can lead to more metabolic stress which is one of the main drivers of muscle growth!
Fat Loss: Coffee intake has been shown to increase the rate of metabolism pretty much ONLY after a bout of physical activity. To make myself clear, that means: no drinking 3 coffees a day with sugar is NOT going to start burning fat off your abdomen. But, if you drink coffee (or just caffeine) without adding too many calories, it can have a positive effect on burning more energy after a workout.
On top of that, Caffeine itself has been shown consistently to promote fat burn during exercise and inhibit carbohydrate usage.
Potential Negative Side Effects and Doses
Coffee has some potential negative side effects as well. Due to caffeine's stimulatory effect on the nervous system, coffee it can promote things like insomnia, nervousness, anxiety, restlessness and other crappy side effects if you drink too much! Caffeine can accumulate in the body for around 5hrs so it only takes a few cups of coffee to potentially get you to that point. The good news is that once people weened off coffee, the side effects subsided.
As previously noted, coffee can have a negative effect with people who already suffer from heart issues. It's highly recommended to avoid coffee consumption or keep it to a minimum.
Adrenal fatigue can occur in people who consume higher than average amounts of coffee (2+ per day).
Over-consumption of coffee can also cause your body to adapt to the stimulus and eventually, coffee might lose its awakening effects. This causes some to drink more in a day to try to achieve the same effect. This can become like an addiction, which makes it difficult to slow down or stop drinking. Withdrawal symptoms can occur when you do stop as well.
So how much is going to stimulate you and how much is going to F you up?
Everyone has different tolerance levels but most humans are within a ballpark range.
One 8oz cup of coffee (regular size) can contain between 100-200mg of caffeine. That's the same proven amount to improve performance in ANY activity. Don't forget about espresso shots. One shot of espresso has a higher caffeine content per ounce than a cup of regular slow drip. My go to drink is a black iced americano. Usually 2 shots of espresso (sometimes 3 if I realy need to get shit goin). A single shot of espresso has roughly 65mg of caffeine, meaning my 2 shots would have about 130mg and my triple shot contains 195mg.
Human Performance has actually been shown to improve between 100-400mg depending on the person but more isn't infinitely better.
On the other hand, 500mg+ daily caffeine is all you need to push you over the edge. That's more than 2 coffees a day. So if that's you, take a step back and re-evaluate your situation.
Are you relying on coffee to get you through the day? Do you have trouble sleeping? Do you suffer from anxiety? Has coffee lost its stimulating effect? You may want to consider chilling out and lowering your intake to 1-2 per day.
Coffee isn't the cause of or solution to all the world's problems (that would be alcohol to those Simpson fans).
The truth of the matter is that caffeine is a drug, and it's hard to not mix up coffee with caffeine because most of the effects (good or bad) or coffee are due to caffeine, other than some additional micronutrients you'll get through coffee.
It's got it's pros and cons, we all love to drink it, we all love getting fired up (mentally or physically) so we say drink coffee, be happy, don't drink too much or you might turn into a jittery coffee-crack-addict with a heart arrhythmia.