The Truth About Caffeine
People have a love affair with their coffee. I can relate. I used to be quite committed to coffee, too. And tea. It was not easy to give up caffeine completely, even after I learned how detrimental it was for my personal health at the time. It was like a bad relationship habit that I kept finding my way back to time and again, only to be reminded why I’d left in the first place. Flash forward twenty years, and I can understand why many of my patients are reluctant to give it up. While caffeine has more than one upside, I often say that it takes more than it gives. Certainly individuals vary, and caffeine might be ok if you don’t struggle with hormone-related issues such as hot flashes, sleep, fatigue, low hormone levels, osteoporosis, or adrenal insufficiency. That’s pretty broad! Let’s elaborate on what’s behind it.
Caffeine gives a false sense of energy. If used regularly, it not only masks your true energy levels, but keeps you cranking through at times when your body actually needs a rest, leading to an even more depleted state. If you’re craving caffeine or sugar stimulants on a regular basis and have a hard time getting through the day without them, it’s a good sign your adrenals are in overdrive—that you’re spending too much time stuck in the “on” position and would benefit from taking a break. Caffeine gives a boost in part because it increases blood sugar levels, which lead to sugar cravings and in turn to cortisol spikes, both of which are highly inflammatory. If consumed regularly, this not only taxes the adrenals but also dysregulates the immune system. Cortisol is a stress response hormone that has an antagonistic relationship with DHEA, which is a steroidal hormone that is critical for the body’s synthesis of estrogens and testosterone. So a disrupted cortisol rhythm can put a strain on reproductive functions.
If cortisol levels rise with your favorite cup of joe, understand that the average half-life of caffeine is about 5 hours, although it varies to some degree depending on body size and how quickly your liver can metabolize it. For the average person, drinking 200mg of caffeine—which is about mid-range for most big chain 12oz coffee beverages—means approximately 100mg of caffeine is still in your system 5 hours later, and then another 5 hours later, 50mg will remain, and so on. So at the very least, it’s important to put limits on the amount, timing, and regularity of caffeine consumption.
Let’s skip over to melatonin, which is the hormone that triggers your body’s sleep response. Melatonin and cortisol are in opposition, with the onset of melatonin happening when cortisol levels are low. Without intervention, a normal circadian rhythm for cortisol consists of a rise after midnight, peaking around 7am and slowly falling throughout the day. When cortisol hits a certain low, melatonin is able to take over and initiate the sleep response. However if cortisol levels remain high late in the day, it will inhibit the release of melatonin. So the more stimulated you get with chronically elevated cortisol levels, or with adrenaline which then stimulates cortisol, the more likely you are to have a hard time getting good quality sleep, and if it’s habitual, the adrenals will begin to tire and slack in cortisol production. This disrupts the internal hormonal regulatory orchestration that happens among the major glands, including the hypothalamus, pituitary, thyroid, adrenals and gonads (HPA axis). Within a short amount of time, a caffeine addiction will re-train this system so that it is dependent on the artificial stimulation. The longer this persists, the longer it can take for the hormonal system to return to a healthy, self-regulated state. On the flip side, the longer you can maintain a well-established, healthy hormonal rhythm, the more resilient your hormones will be at rolling with the occasional disruption.
That’s a pretty simplified overview. Remember that the body is a sophisticated organism and that hormones pretty much never act alone or as single-function bio signals. Thus melatonin is part of a whole host of anabolic hormones that are more dominant at night, and which regulate growth, healing and repair. If you interfere with your melatonin signals because you’re drinking too much caffeine or consuming caffeine too late in the day, these necessary repair activities are hampered.