What Is The Adrenal Response To Caffeine?

University of Rochester experts say caffeine, a naturally occurring chemical in cocoa beans, tea leaves and kola nuts, for example, is consumed by approximately 90 percent of the people in the world. Doctors classify caffeine as a drug because it stimulates the central nervous system and induces the neurons in the brain to fire more rapidly. The pituitary gland, located at the base of the brain, perceives the increased brain activity as stress, prompting the adrenal glands to increase their production of stress hormones.

Adrenal Function

The adrenal glands, located above the kidneys, produce hormones that regulate a variety of bodily functions. The outer portion of the adrenal gland, known as the adrenal cortex, produces aldosterone, which regulates blood volume and blood pressure; the male sex hormone known as androgen; and cortisol, classified as a stress hormone. The adrenal medulla, the inner portion of the adrenal gland, produces hormones that help you cope with emotional and physical stress, including epinephrine, also called adrenaline, and norepinephrine, or noradrenaline. Consuming large amounts of caffeine each day can cause your adrenal gland to work overtime and lead to adrenal fatigue.

Stress Hormones

Too much caffeine -- or caffeine consumed at the wrong time of day such as in the evening -- disrupts normal adrenal function and stimulates an increase in the production and secretion of three important stress hormones, adrenaline, noradrenaline and cortisol. The release of adrenaline and noradrenaline causes your pupils to dilate, your heart to beat faster, your blood vessels to dilate and your blood pressure to increase. This response readies your body to react to stress, allowing your brain to clear and your muscles to contract. Cortisol increases blood sugar levels to provide energy to deal with the stress, whether real or perceived. Cortisol also suppresses the immune system and aids in the breakdown of fats and carbohydrates.

Caffeine Effects

Dr. Marcelle Pick of the Women to Women Clinic says drinking one to two cups of coffee or other caffeinated beverage per day likely causes no harm, but more than that can stimulate your body's natural "fight or flight" response. The caffeine tricks your adrenal glands into thinking you are in a stressful situation; and although this makes you more aware in the short term, your body becomes more fatigued after the "state of emergency" passes.

Risks

The function of your adrenal glands and your body's ability to deal with stress serve a great purpose when the stressful situation really requires a "fight or flight" response, as when you are confronted with a life-or-death situation. Unfortunately, much of the stress in today's society occurs while people are sitting at a desk or driving a car, causing a sort of false alarm to activate the adrenal response. Caffeine exaggerates the adrenal response to daily stress as shown in a study published in 2002 in "Psychosomatic Medicine" which documented a 32 percent increase in ephinephrine following caffeine consumption. The authors concluded that the amplified adrenal response may contribute to an increased risk for developing coronary heart disease.