Ask Miranda Entry For 30 August 2008

Adrenaline, Cortisol and the Insulin Connection

Adrenaline, Cortisol and the Insulin Connection

Our built-in “fight-or-flight” response releases the stress hormones adrenaline and cortisol from the Adrenal Glands. The role of these two hormones is to make sugars readily available for your muscles for quick response (cortisol) and for your brain for quick thinking (adrenaline). A good thing when you are being chased by a lion or in a comparable scenario. Not so good when you are stressed out, sedentary and eating sugar. Let’s see how this all links together.

Here is the process (over)simplified:

- Our brain perceives a threatening event or stressful situation

- Our sympathetic nervous system is called into action (fight-or-flight response)

- The adrenals, which are two glands that sit on top of the kidney’s, are activated to release large amounts of adrenaline (epinephrine) and cortisol into the bloodstream

- Adrenaline increases the body's metabolic rate and acts with our sympathetic nervous system to divert blood (and thus nutrients) from areas not required for fighting and fleeing (such as from our digestive system, skin and kidneys) to areas that require blood for fighting or fleeing (muscles, heart, lungs and brain).

- Cortisol works with adrenaline and other nervous system hormones to mobilize fats, sugars, and proteins from tissues so that we have the energy to sustain our "running or fighting" (our adaptation to stress). It also shuts down our immune system in order to conserve energy for fleeing*.

- When mobilized sugars enter the bloodstream ready to be pulled into action, insulin is released.

- The role of insulin is to notify the liver of the amount of sugar in the blood and to transport insulin into the body’s cells.

- Cell receptors detect insulin and allows for sugar to be unloaded from the bloodstream into the cells

- Long-term stress (also high sugar diets, lack of exercise, and other insulin stimulants) lead to periods of high insulin in the bloodstream, which results in cells full of sugar

- With the cells full, cell receptors no longer allow for insulin to transport sugar from the blood into the cells

- The pancreas in turn, releases more insulin to try and get the cell receptors to “open up”, but the cells cannot take in the sugar from the bloodstream. At some point the pancreas starts to fail, leading to the death of insulin producing cells.

- Further exasperating the problem, cells reduce the number of insulin receptors.

- Full-blown insulin resistance has occurred.

- Extra sugar in the bloodstream is stored as fat in fat cells**

- Fat cells are filled up and high sugar levels remain in the bloodstream. Welcome to Type II diabetes.

*Elevated cortisol and elevated insulin levels creates an insatiable appetite for carbohydrates and fat.

**Accumulation of excess 'stress fat', the layer of fat around the abdomen, is the only type of fat on the body associated with death. This type of fat has been linked to heart disease, high blood pressure, stroke, cancer and diabetes.

Highest Return-on-Investment Stress-reducing Applications

-ER4YT (that should be a no-brainer)

-Exercise, exercise, exercise (in addition to relieving stress, exercise increases the effectiveness of insulin. Also, building lean body mass will increase your number of insulin receptors)

-Avoid man-made sugars

-Avoid artificial sweeteners (they break down into methane during digestion and are damaging on a cellular level)

-Eat plenty of BTD-compliant non-starchy vegetables, proteins and fats

-Limit high-glycemic fruits/foods or consume moderate amounts within 30 minutes after exercise (when the cells are primed to take in and utilize the natural sugars)

-Limit caffeine. Caffeine decreases the effectiveness of insulin in much the same way as obesity does. Caffeine also increases the levels of the stress hormone adrenaline, which may also impair the action of insulin. I am a proponent, though, of a having a cup of coffee before strenuous activity. The theory behind this is that glycogen, or sugars, are the primary source of energy in the muscles, whereas fat is used as a ‘back-up’ fuel. Once glycogen supplies are exhausted (after 2 hours of vigorous activity) fat comes more into play, but this is not as easily accessible. Caffeine before a race may release fat into the blood stream quicker and help ‘save’ glycogen so this does not run out suddenly, leaving a feeling of ‘hitting a wall’ (Vinson & Dabbagh; Nut Research 1998; 18 (6): 1067-75)).

-Don’t smoke. Smoking greatly increases free radicals, which are looking to do some cellular destruction. (Free radicals are molecules with an odd, unpaired electron. Free radicals are very unstable and react quickly with other compounds, trying to capture the needed electron to gain stability. Generally, free radicals attack the nearest stable molecule, "stealing" its electron. When the "attacked" molecule loses its electron, it becomes a free radical itself, beginning a chain reaction. Once the process is started, it can cascade, finally resulting in the disruption of a living cell.)

-Last but not least, Relax! 8-)