Stress: Cortisol and Insulin Resistance

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It’s understood that a good diet and regular exercise are important ingredients for good health. However, stress management is also an essential component of the good health equation. Stress impacts blood sugar regulation in a way that often leads to insulin resistance which is a precursor to diabetes and a myriad of chronic conditions i.e. cardiovascular disease, Alzheimer’s, hypothyroidism, obesity and cancer. This is why researchers are particularly focused on the impact stress has on weight and insulin resistance in addition to nutrition and physical activity. Understanding how stress and the subsequent release of hormones contribute to disease progression is a big step towards prevention.

Cortisol and the “Fight or Flight” Stress Response

Cortisol is one of the hormones released from the adrenal glands in response to any type of psychological, environmental or physical trigger (i.e. infection). Many people associate cortisol with the “fight or flight” mechanism. Cortisol is also part of the hypothalamus-pituitary-adrenal (HPA) –axis that impacts sex hormones and thyroid function. Research has demonstrated that it isn’t necessarily the stress that is significant but rather how it is “perceived” that is important. When cortisol is released in response to a stressor, all non-essential bodily functions are temporarily put on hold in order to deal with the situation. The body needs to have as much energy as possible available, in the form of blood glucose, so it signals insulin to restrict glucose uptake to the cells. Cortisol also triggers glucagon to release stored glucose from the liver. Some of the ways cortisol release impacts the body in response to a stressor includes:

  • Signals glucagon (which stores glucose in the liver) to release additional glucose into bloodstream
  • Suppresses insulin
  • Suppresses immune function
  • Suppresses reproductive function
  • Weakens gastrointestinal tract
  • Constricts blood vessels

Once the threat has resolved, insulin rebalances blood glucose levels and glucose is welcomed back into the cells. At this point the body is ready to rest and store energy for next time. This evolutionary adaptive response has ensured the survival of humans over time. The problem however, lies in the repetitive and constant activation of the cycle. Ultimately the signaling process becomes impaired and cells become resistance to insulin, which has far reaching consequences.

Signs of Insulin Resistance

  • Inability to maintain or lose weight
  • Headaches
  • Hypothyroidism
  • Reduced memory performance
  • Poor sleep
  • High cholesterol and triglycerides
  • Poor results on blood glucose levels

Most individuals that develop insulin resistance actually have normal or close to normal blood glucose levels. Levels are able stay low due to the excessive release of insulin, which is trying to maintain the balance in the bloodstream. Just over a decade ago it was estimated that 60 to 70 million people fell into this category. Approximately 25% of this group progressed to having type 2 diabetes as their bodies couldn’t sustain the insulin resistant state. Today, the numbers are even higher.

What is Insulin?

Insulin is a hormone that acts as a regulator of blood glucose levels by controlling glucose uptake into the cells (and out of circulation). As described, with repeated acute stress the pancreas is suppressing insulin and repeatedly flooding the bloodstream with glucose both by not allowing it into the cells (resisting insulin) and releasing more from the liver as well. As this process becomes chronic, it becomes more difficult to manage. The body continually requires more insulin to reduce glucose levels, and eventually cells end up insensitive to the insulin. The effects of high insulin also include disrupted cellular metabolism and increased inflammation. A person’s susceptibility to impaired insulin signaling has a genetic component that is more pronounced in certain ethnic groups, i.e. Latinos and Asian Indians. For these groups the lifetime risk of developing diabetes is estimated to be as high as 50% and it’s emerging in youth. One research study identified a clear relationship between disrupted cortisol levels and insulin resistance in Latino children as young as eight years old.

Ways to Restore Balance

Some ways to reduce stress and bring your body into balance include:

  • Sleep– sufficient and regular routine
  • A balanced diet that includes a variety of vegetables, low glycemic foods, minimal processed food, moderate protein, and essential fatty acids.
  • Dietary fiber (30-50g/day)
  • Regular exercise
  • Quit smoking
  • Weight loss, if overweight
  • Meditation, yoga, or Thai-chi
  • Regular use of herbs and spices
  • Herbs to balance HPA axis, i.e. Ashwaganda, Rhodiola, Licorice root, etc.
  • Magnesium, alpha-lipoic acid, vitamins C, E, B6, B12 and D.

For many people with insulin resistance, the condition often goes unnoticed in routine bloodwork because insulin drives the glucose levels down to a normal or near normal levels. This masks the problem, which can readily be identified with the simultaneous analysis of blood insulin and glucose levels. Unfortunately, doctors don’t usually order both tests, relying primarily on blood glucose and A1c. If a problem is suspected it is prudent to request both tests. As with most chronic illnesses, risk factors can be modified even if you do fall into a susceptible population. A comprehensive management plan that incorporates diet and lifestyle modifications along with supplemental support can be effective in turning the tide. It is always important to remember that it took time to create the condition and it will take time to reverse it as well.




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