Wednesday, August 25, 2010

Coffee Break

We are surrounded by coffee! In our commutes to work (many of us are drinking it), post lunch in the work place, in our lectures, etc. I mean there is literally a Starbucks on every corner. The majority of us are reliant on this caffeinated brew but are the physiologic effects beneficial, negative or does it remain unclear? Well, as is true of much scientific research, it is controversial but it seems that the upside may win out.

Multiple organ systems are effected by caffeine; no wonder it successfully helps us function in the face of fatigue, boredom, after a large meal...The second we start sipping a Cup of Joe the widespread response is initiated. The major systems triggered are cardiovascular, neurological, and metabolic (pretty much the most important systems). Think about the sensations that arise over the course of a cup of coffee-maybe a little hot, jittery, energetic and focused just to name a few.

Since society these days is focused on weight loss (primarily since we dug ourselves a hole in the last few decades) one of the main questions surrounding coffee is does it help us lose weight? In addition, will it help us prevent diabetes? The answer is possibly. Evidence from studies (there have been almost 20,000 in the last few decades) indicate that caffeine induces thermogenesis, basically induces more energy expenditure. However, in these studies patients drank up to 6 cups/day for only 100 kcal burned that day. I don't know about you all but 6 cups sounds like a tremendous amount. The possible etiology of this increase in energy expenditure via thermogenesis may be via an induction of lipolysis (increased fat metabolism). Part of this increased metabolic rate is likely secondary to increased peripheral resistance which leads to increased cardiovascular work and higher blood pressure. This is the reason that those with high blood pressure should only consume coffee moderately if at all. People with diabetes should also be cognizant that the beverage most of us rely on may actually impair sugar metabolism.

I have alluded to stress hormones in previous posts, specifically epinephrine. It turns out that epinephrine (one of the fight or flight hormones) is increased in the circulation with coffee consumption. As we discussed previously, when we are stressed our body wants to keep a lot of sugar in the blood stream so we have a readily accessible source of energy. Well, this surge in epinephrine causes a temporary, or possibly long-term, insulin resistance which can be detrimental to diabetics. For non-diabetics it may make sense to hold off on that afternoon coffee until we have a chance to digest in order for the blood sugar to return to its baseline level. However, I understand the clock is ticking once lunch is over till the afternoon fatigue and loss of focus hits (a low carb. meal is one of the best preventions). I am with you all!

How exactly does coffee fight off that fatigue? Basically it works to overcome the activity of adenosine (a major compound involved in energy) which when bound to specific receptors slows the body down. The amount of adenosine increases throughout the day in order to prepare us for bedtime. When caffeine is consumed it competes with adenosine and usually wins by binding to its specific receptors and the result is an increase in energy. If we are going to have an increase in energy we certainly want to be able to maximize it for its full potential.

We have all heard an extensive amount about Alzheimer's disease and Parkinson's disease in the media the last few years. Studies have indicated that inhibiting adenosine (the bodies chill pill) may actually slow the build up of amyloid plaque which is associated with Alzheimer's disease. Additionally, dopamine levels may also be preserved with caffeine and thereby delaying or preventing the onset of Parkinson's disease. All good news but yet to be concluded and it seems like we need a high amount of coffee daily to reach these benefits. Who knows maybe caffeine pills will become the new Omega 3 fatty acids craze.

For awhile I was on a big green tea kick (see previous post, "It's Good to be Green") but now I am just confused. Maybe I will alternate days or weeks between green tea and coffee.

Good news (or maybe not) I am now on twitter. You can follow my daily health related tips at www.twitter.com/dodellmd (or just click on the upper right corner of this page to be linked). I was resistant to get involved in this whole other world (thought Facebook was enough) but it is a great way to get all your news and other daily information in one place.

Hope you learned something from this post!

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