Stress: Cortisol, Blood Sugar & Disease

I know I promised this stress information last week, but I had too much going on and could not find the time to post. Normally I’d try to squeeze it in, but given the topic, I figured it was better to let it go and revisit it this week when I have more time.

We experience stress when life’s demands exceed our ability to meet those demands. Each of us has a different capacity to handle stress – this is an important thing to remember. One person may be able to juggle a full-time job, family, cleaning the house, volunteering, and cooking meals all without issue, while another may experience severe stress and fatigue with a full-time job and no family to worry about. Another important point: stress can be physical (such as a knee surgery), emotional, psychological, or social; short-term or long-term; and real or imaginary/perceived.

Acute stress is the body’s initial response to stress, otherwise known as the “fight-or-flight” response. Remember, fight-or-flight refers to a series of changes that rapidly occur inside the body when we encounter a stressful situation. These specific changes actually prepare the body for quick thinking and fast-acting behavior so we can optimize our response to the stressful encounter. Energy reserves of fat, protein and carbs are rapidly mobilized through tissue breakdown, and this energy is transferred to our arms and legs so we can move quickly. Adrenaline levels increase, heart rate increases, blood pressure rises, body temperature increases, and we become very alert. The idea is that we will deal with the situation and then our body will quickly return to its normal balanced state.

Chronic stress, however, interferes with the natural fight-or-flight response. When someone is under chronic stress (and I think it’s safe to say we’ve all experienced chronic stress), cortisol levels increase. Cortisol is a hormone that helps the body respond to stress. It is useful in small amounts but very damaging in large amounts. The chronically high cortisol levels contribute to muscle loss, fat gain, and accelerated breakdown of bones and tissues. Symptoms of too much cortisol include weight gain, fatigue, blood sugar fluctuations, increased appetite, carbohydrate cravings, muscle weakness, low immunity, anxiety and depression, and low sex drive. Eventually, chronically high cortisol levels lead to inflammatory diseases such as diabetes, obesity, heart disease and arthritis.

Research has made it clear that there is a strong relationship between chronically elevated cortisol levels due to chronic stress, and long-term health. One of cortisol’s original roles is to encourage the body to refuel after responding to stress. However, when we have chronically high levels of cortisol, we are always hungry and craving certain foods, because our body thinks we need to refuel. This can lead to over-eating, and the fat tends to accumulate in the midsection – so it is readily available for the next stress response. This type of abdominal fat is associated with heart disease, diabetes and cancer.

Finally, I want to share the connection between chronic stress, elevated cortisol levels, and blood sugar imbalance. Insulin is another hormone I’ve talked about occasionally. Insulin’s primary role is to regulate our blood sugar levels. Other roles of insulin are to store fat in our cells, store sugar in our liver and muscle cells, and instruct proteins to build muscle. Someone with healthy insulin levels and insulin responses will optimally utilize the hormone and have internal balance.

During the stress response (fight-or-flight), all of our cells are instructed to ignore insulin, so as to keep the energy (fat, proteins and carbs) in the blood for rapid mobilization and use as our body responds to the stressor. Cortisol sends a message to the cells that rather than storing energy, they should break down their stored energy and send it into the blood. This is quite effective when we are actually facing a stressful situation, because we suddenly feel a surge of energy and can move quickly.

However, with chronic stress and chronically high cortisol, the body is continuously told to ignore insulin, which leads to insulin resistance. This is when our body becomes desensitized to insulin and therefore we have too much sugar in our blood, leading to weight gain, increased appetite, carbohydrate cravings, and diabetes.

Later this week I will talk about some important nutrients for someone who is under a lot of stress.