Mmm…coffee. I will be honest, I can’t imagine starting a day without it. Despite its stimulant properties, I find it oddly relaxing to enjoy a piping hot mug of coffee before the sun peeks over the horizon, in that quiet hour before my day gets started. I’m not alone in this — caffeine is, after all, the world’s most-consumed drug. Of course, the presumption is that it’s highly addictive and we’re all hooked, but that’s not actually true. Even better, it seems that coffee provides more health benefits than we knew about in decades past. I can’t help but ask: Could coffee actually be good for you?

Wait…not addictive?

If you’ve ever stopped coffee cold-turkey, you probably know the smashing headache and mind-numbing fatigue that takes over your life for a day or two, especially if you habitually drink four or more cups each day. The assumption has always been that this was a clear sign of your addiction to caffeine. But that’s not the case. It’s listed in the pharmacopeia as a stimulant, but not an addictive substance.

So why the withdrawal symptoms?

Caffeine blocks a neurotransmitter called adenosine, a naturally calming hormone. As the day progresses, adenosine increases, helping us to feel tired, but caffeine will inhibit that. If you suddenly withdraw your daily dose of caffeine, adenosine spikes back up with a vengeance, making us feel dopey, and takes a few days to return to normal. 

And the headache? Caffeine also acts as a potent diuretic, so that sudden withdrawal disrupts your body’s ability to adjust. A big part of that blinding headache is dehydration. But this also rebalances in a few days, provided that you drink extra water while your system recalibrates.

What else contains caffeine?

Caffeine is naturally found in over 60 plants, including tea, cacao (chocolate), some herbs like yerba maté and guarana (often found in fat-burning formulas), and kola nut. It’s artificially added to soft drinks, energy drinks and even some skin-care products. 

Is tea better or worse?

Black tea often has more caffeine than coffee, per cup, but it depends on preparation and brewing time. Tea leaves (just like coffee beans) need to be roasted to release the caffeine when it comes time to brew. The longer tea is brewed, the more concentrated it becomes. Green tea, however, is not roasted, so while the leaves technically contain the same amount of caffeine as their roasted counterparts, the caffeine is not easily released into water, no matter how long you brew it. It’s why you can drink green tea ‘til the cows come home, and not feel over-stimulated. You do, however, get most of the good stuff, including catechins (anti-inflammatory polyphenols) and L-theanine. 

What’s the science of coffee?

Besides caffeine, coffee also contains antioxidants, mostly in the oils. The caffeine is metabolized in the liver and broken down into 3 metabolic compounds called dimethylxanthines (paraxanthine, theobromine, and theophylline). These are responsible for fat-burning, blood vessel dilation, diuretic activity, and airway dilation. If you’re a migraine-sufferer, you’ll know that a strong espresso will help alleviate the headache.

On the downside, methylxanthines are also estrogen disruptors, which is why coffee has been linked to fibroids, endometriosis, and fibrocystic breasts. But, it seems that this correlation is only seen at 4-5 cups or more per day. For women consuming 2-3 cups of coffee per day, the research suggests that they actually do better, hormonally speaking. So interesting. The major caution here, however, is pregnancy. More on that in a moment.

So… what are those health benefits?

In general terms, coffee has been shown to:

• Enhance physical performance, especially muscle endurance
• Sharpen cognitive focus and increase mental alertness
• Inhibit drowsiness effects of antihistamines
• Lengthen life, especially in women
• Improve how the body processes sugar
• Protect the liver
• Decrease the breakage of DNA

Let’s talk about dosage — where’s the benefit, and what’s “too much”?

The amount of coffee associated with all those health benefits, and generally considered safe, is around 200-400mg of caffeine daily. The number of cups to get that amount depends on the type of bean, how finely the beans are ground, and the brewing method. But generally speaking, one cup of coffee contains around 200mg of caffeine.

But consider the size of your “cup” — a Grande at Starbucks contains about 330mg of caffeine, so two of those every day can put you over the healthy limit.

When is it too late to drink coffee?

It’s all about the half-life of caffeine.

Put simply, “half-life” is the amount of time it takes for a drug to decrease by half, in the bloodstream. This depends on age, gender, weight, genetics, diet, and your overall health, of course. But it’s a good starting point.

For caffeine, the half-life is 5 hours.

Let’s use the 330mg Grande coffee as an example:

• If consumed at 7 a.m., the caffeine in your body will be down to 165mg by noon
• By 5 p.m., it will 82.5mg 
• If you’re heading to bed at 10 p.m., you’ll still have 41.25mg of caffeine in your system

So, who needs to be careful of coffee, or avoid it entirely?

• Anyone with sleep issues should probably avoid caffeine in all its forms
• Anyone with an anxiety disorder, according to the National Institutes of Health guidelines
• Pregnant women & women trying to conceive 
• Women who are breastfeeding — caffeine is easily absorbed into breast milk, and can lead to increased agitation and sleep challenges in a newborn
• Women over 65 with low bone density — risk of hip fracture increases 3x with more than 3 cups of coffee per day

LAST THOUGHTS

Like many things that are natural, coffee can be both good and bad. It’s up to us to make smart choices with how we consume it. But for now, it’s good to know there’s less reason for alarm if you enjoy one or two delicious cups of coffee in the morning.