|No Caffeine for Me!
Cortisol is a hormone that is related to stress. At a very basic level, cortisol is created as a response to stressors in our environment. Back when we were still chucking spears at deer and chasing down antelope, cortisol was helping to preserve our lives by giving us quick energy by signalling to our livers that it was time to engage in a process known as gluconeogenesis. This process is basically the breakdown of amino acids, the building blocks of protein, into glucose - one of the two monosaccharides (the healthy one) that our bodies use for fuel.
Picture this - you're walking across the street, enjoying the day, when suddenly some inattentive driver tries to turn and doesn't see you. Your heart rate speeds up, and you get a little burst of speed to quickly sprint out of the way of that hazard to your bodily health. That was the release of cortisol (and a host of other hormones, but we're focusing on cortisol for now), spurring the creation of glucose and the quick energy needed to make that sprint. It's similar to what might have happened in the wild if your paleolithic ancestor came upon a wolf or bear while foraging and hunting. And it's a great bodily response for a very specific cause.
The problem arises in this modern age, where we have lots less specific stressors like that, but a virtual plethora of general stressors. Traffic. Bad sleep. Job worries. A constant barrage of bad news from the media. The list goes on and on. And that constant barrage has the effect of keeping cortisol hanging around in our bodies instead of just releasing it when we really need it.
The negative effects of this constant presence of cortisol are many. One of them is decreased cognitive performance. One of the effects of the constant presence of cortisol and other stress hormones is to injure or even kill hippocampus cells. The hippocampus is the section of the brain that contains learning and memory centers. Another is the creation of more abdominal fat. Among its effects, Cortisol causes excess fat to be stored at a higher rate than normal, mostly in the abdomen. Abdominal fat can take the form of both subcutaneous fat, which is the fat you can see around your midsection, and visceral fat, a much more serious condition where the fat is located surrounding abdominal organs and can lead to insulin resistance (which is the cause of a number of effects in the human body such as heart disease, some cancers, and more).
All in all, not a good situation in which to find yourself.
So what does caffeine have to do with all this? As a stimulant, caffeine increases stress in the body - creating conditions via its very nature that emulate the effects of sudden stress, and causing the release of more cortisol.
I don't have a huge problem with belly fat, but I have more than I'd like - I'd like to see a little more improvement in the visibility of my abs (what's the point of doing all these planks if you can't see the improvement?) in the all-important looking-good-naked category. And as the link from Harvard said above, there are other concerns there as well.
So it's time to drop the caffeine from my diet, I think. Being a father of two young kids, my sleep's not likely to get any better, as hard as I try. But caffeine is something I can control a little more. Either I take it in, or I don't. So I won't, for 30 days, and I'll report back to you on how I'm feeling and looking.
Questions? Comments? What has your experience been with caffeine and these issues? Post below!