Drinking Coffee & Stress On The Adrenals

Coffee drinking is a pleasurable habit indulged in by over half the adult population in the United States, according to the website CoffeeResearch.org., with the average coffee drinker downing a little over three cups per day. However, caffeine in coffee may exert stress on your adrenal glands that has a cumulative effect on your overall health.

Norepinephrine and Cortisol

If you think back to when you first started drinking coffee you might recall its considerable stimulant effects. Perhaps you experienced a slightly pounding heart or heightened alertness that lasted for much of the day. That first cup of coffee likely doubled your levels of norepinephrine, a neurotransmitter that increases alertness, and also increased your adrenal glands' output of the stress hormone cortisol, which speeds up your heart rate and increases your blood pressure, according to Dr. Norman Shealy, author of the book "Life Beyond 100: Secrets of the Fountain of Youth."

Accommodation

Caffeine is a stimulant drug that is slightly toxic and must be processed by your liver before it can be safely exported from your body. Another characteristic of caffeine's physiological effects is your body's ability to adapt to the stress it causes, a process known as tolerance. Tolerance to caffeine occurs relatively quickly. Just one week after you began a regular coffee drinking habit your cortisol level accommodated to the caffeine, barely budging with that first morning cup. After a few years of coffee drinking your first cup may simply give you a slight lift that gets you out the door to work, where a few more cups will fuel you through your morning and afternoon. Over time, the repetitive slight drain on your adrenal glands accumulates, draining your reserves and depleting your ability to adapt to stress, according to Shealy.

Gender

Your gender may influence your response to caffeine, according to a study published in the November 2009 issue of the journal "Pharmacology, Biochemistry and Behavior." The laboratory animal study found that caffeine increased anxiety-like behavior in males but not in females. Caffeine also damaged a part of the brain known as the hippocampus, which is involved in memory and learning, an effect that was also only observed in males, in this study. Researchers theorized that the lack of these effects in females may be due to the effects of estrogen, which exerts anti-anxiety and nerve-protective benefits. Further human trials are needed to verify these preliminary results.

Weight Control

A study published in the June 2008 issue of the journal "Physiology and Behavior" found that caffeine causes a stress response that influences food choices and body weight. Caffeine-treated laboratory animals showed decreased consumption of salty and sweet foods, with a more pronounced effect in females than in males. One explanation for the appetite-suppressing effects may be increased levels of adrenal hormone, which causes the brain to produce signals of satiety. Researchers conclude that caffeine's mild adrenal stress effect may be a useful therapy in treatment of obesity, in some cases. Further human trials are needed to more clearly define the effects of caffeine-induced stress on appetite and food selection. Consult your doctor before using coffee or any other stimulants for weight loss or to treat a medical condition.