STRESS FAT: The Effects of Cortisol
The human body is a sophisticated machine that utilizes a series of hormonal reactions to alter the balance of the cellular functions. Cortisol is a hormone that helps regulate the balance of storing and releasing fat. It stores fat by increasing the activity of lipoprotein lipase (LPL) a fat storing enzyme. It helps burn fat by increasing the release of hormone sensitive lipase (HSL) a primary fat releasing enzyme. It assists in releasing fat from stored fat cells; however, the fat still needs to be burned via other metabolic avenues in the body, otherwise the fat will be re-stored in fat cells.
Not all cortisol release is a bad thing. In fact, acute elevations in cortisol can help promote fat burning. Chronic levels of cortisol production become problematic causing fat storage and muscle wasting. This is due to the fact that high a level of stress activates sympathetic neuron sensitivity increasing the production of neuropeptide-Y (NPY) production.
The danger of cortisol is when it is paired with insulin. Insulin is an anabolic hormone that is responsible for maintaining blood sugar levels. When insulin is released it opens up fat cells to allow the excess sugar to enter. When the body is under a sympathetic episode blood sugar rises alerting insulin to release to clear the sugar from the bloodstream. Cortisol is used to turn off cellular metabolism and is known as the antagonist to insulin. When both hormones are released at the same time they increase the activity of lipoprotein lipase; while at the same time insulin inhibits cortisol’s influence on hormone sensitive lipase. The end result of this polarizing union is ultimately fat storage. When a person is cognitively stressed out they activate the sympathetic neurons (neuropeptide Y) forcing a heightened blood sugar response. The brain will then begin losing glucose and will activate the craving response to force the person to eat carbohydrates. High levels of carbohydrates will accentuate the production of insulin. This cycle will continue suppressing HSL resulting in increased fat storage
In addition, high levels of insulin also suppresses another major fat burning enzyme known as CPT-1. Without these fat burning enzymes the body has a difficult time shrinking fat cells. To make matters worse, the polarizing relationship of insulin and cortisol causes the body to become more insulin resistant. More insulin is required to counteract the effect of cortisol. This can lead to even greater fat storage, making the fat burning factor reduced to a minimum.
It is often speculated that cortisol causes belly fat this is not the case; however, when insulin is released to combat the effects of cortisol that is when belly fat increases.
There is a positive aspect to cortisol to help enhance the burning of fat. During events when the body is under an acute controlled sympathetic response where there is an increase in human growth hormone (HGH), and the catecholamines epinephrine, and norepinephrine, with lower levels of insulin fat burning is increased. This is because insulin’s effect is dampened allowing the other hormones to initiate a greater anabolic response in the muscle cells enhancing the sensitivity of the muscle cells aerobic and anaerobic enzymes. When the aerobic pathways are activated fat is needed to fuel the muscle via the mitochrondria. The end product of aerobic metabolism is the production of ATP. ATP is the primary phosphate energy compound of the body.
Keep in mind that this accentuation of fat burning via cortisol release only occurs during short term, high intensity events. For example, resistance training with high intensity for 20-30 minutes is all that is needed to activate the benefit of cortisol fat burning effect. Events that go beyond this time period will be counterproductive and cause cortisol levels to increase too much, which will then increase the release of insulin resulting in the fat storage sequence.
When cortisol levels spike from a stressful event it is best to reduce cortisol as fast as possible. Meditating and consuming amino acid enriched foods will help reduce the negative effects of cortisol allowing the restoration of muscle tissue. Consuming protein or branched chain amino acids following exercise is a great way of stopping the lingering effect of cortisol production.
Another function of cortisol is the effect it has on thyroid function. The thyroid is the body’s regulator gland. It stores and produces hormones that affect the function of virtually every organ in the body. Cortisol is necessary to stimulate the release of thyroxine, a thyroid hormone. Low levels of cortisol interfere with the production of thyroxine resulting in a condition known as hypothyroidism. High levels of cortisol has the opposite effect, this condition is known as hyperthyroidism. A healthy thyroid converts thyroxine (T4) into triiodothyronine (T3). Cortisol inhibits the conversion sequence and causes an increases levels of revers thyroid hormone (rT3). Proper thyroid function depends on a balanced cortisol levels.
Insomnia, drinking alcohol, coffee, prolonged exercise bouts, skipping meals, chronic cognitive and physical stress are all responsible for increasing cortisol above the appropriate levels.
Proper sleep, massage, relaxation techniques, protein, eating nutrient dense low glycemic foods, BCAA’s, physical affection, de-stressing, saunas, hot baths, spa modalities, herbal teas, magnesium supplements are some ways to naturally reduce high levels of cortisol.
If you are over-fat, sluggish, and feel over stressed you could be suffering from high levels of cortisol. If you feel that you do, I recommend that you see a health care professional to help test your cortisol levels to confirm your feelings.
Daryl Conant, M.Ed.