Caffeine: Friend or Foe?

Coffee is amazing. It's honestly the one true nectar of the gods. It is a miracle in a cup and the best pick-me-up when you're feeling bogged down. Coffee has many known health benefits. It is a potent antioxidant and coffee consumption has been found to have an inverse correlation (more coffee, less disease) with diabetes mellitus, Alzheimer's, and some types of cancer [a]. Drinking coffee before exercise can also help increase endurance and help you push out those last few seconds of a high intensity workout [b].

As I've started my new job, I've noticed my coffee intake dramatically increase, and with that, I've also started to notice that it's not so perfect all the time. With every cup I drink, I notice a slight edge of anxiety. It also messes with my sleep and leaves me awake at night staring at the ceiling wondering why I thought a quadruple shot of espresso was a good idea. This got me questioning what the evidence says about the downsides of coffee (if they even exist). So, what did I find out?

One of the negative effects coffee can have on its consumer is insomnia. Caffeine has a half life of about 5 to 6 hours [c], so even if you drink it early in the afternoon, it will still be in your system by the time you need to go to sleep. Here's an example of how to calculate that: if at 4 PM you consume 165 mg of caffeine, the amount in a grande iced coffee from Starbucks, you will still have 82 mg of caffeine in your system at 10 PM. This can leave you tossing and turning and unable to sleep, and lack of sleep of course has its own stack of negative effects on health. So, next time you reach for your venti quad espresso afternoon pick-me-up, you might want to think twice about what time you plan on falling asleep at night.
Not only does coffee have the potential to shake you up all night long like an AC/DC track, but it also can exacerbate anxiety and panic disorders [d]. In addition, people with anxiety and panic disorders have been found to have an increased sensitivity to the effects of caffeine [e]. Coffee consumption may also heighten psychotic symptoms and hostility in individuals with psychosis-related disorders [d]. If you're a health care worker, consider asking your patients about coffee intake so you can appropriately monitor and intervene with caffeine-related side effects [d].

Individuals with or at risk for hypertension should also be aware of the downsides of America's favorite beverage. Coffee raises blood pressure and heart rate, and caffeine consumers have higher blood pressure on average than non-caffeinators [f]. Individuals with hypertension should ask their doctor if it's safe to consume caffeinated beverages and should consider limiting coffee consumption to less than 2 cups per day [f]. Risk factors for hypertension include - but are not limited to - the following: age over 65, race (common amongst Black people even at early ages), family history, obesity, lack of physical activity, tobacco use, high sodium intake, stress, and chronic conditions such as kidney disease [g].
With this information taken into account, coffee should certainly be used in moderation. I say this as I sip my iced coffee at 7 PM, but since it's the weekend I don't quite have a bedtime goal I need to hit for tonight. Spoken like a true coffee addict. Do you think coffee's pros outweigh the cons? Comment below to join in the conversation.