Understand your stress

Acute vs. chronic stress


Close-up on… chronic stress

Cardiovascular Function and Salt

The stress hormone cortisol helps to regulate the balance of salt and water in our body. This is essential because too much or too little salt can affect the normal functioning of our heart. The electrical currents that stimulate our heartbeat and the functioning of our heart are highly dependent upon salt (sodium) levels.

You have surely noticed that your sweat is a little salty. We lose salt when we sweat. This is his why drinks like Gatorade® have salt in them. If our sodium levels become too low, then cortisol stimulates a craving for salt.

i.e.: Pizza after moving day really hits the spot!

Cardiovascular Function and Water

Our body is mostly made of water; the range is between 55% in women to 65% water in men. Our blood is fluid because of this water content. The amount of water present contributes to what is known as blood volume.

Blood volume is directly related to blood pressure. Higher blood volume means higher blood pressure. A lot of water makes the heart work harder. This is why certain blood pressure medications (e.g. diuretics) are designed to reduce the amount of water in the system. Less water means lower blood pressure.

TAKE HOME MESSAGE

A big problem in today’s world is that we often do not use up the energy we consume. When we were mammoth hunters, we ran like crazy and used up the energy. But today, the stress response system secretes stress hormones when we are stuck in traffic or sitting at our desk at work. Why do we speak about mammoth hunters?

If everyday levels of stress hormones are high then the delicate salt/water balance that keeps our heart working normally can be disrupted. In the long-run, this can lead to cardiovascular disease.

Cholesterol

Stress can also indirectly lead to high cholesterol levels. Repeated exposure to stress often leads to unhealthy lifestyles.

i.e.: Eating a diet high in saturated fats, weight gain, increased tobacco and alcohol intake, and decreased physical activity.

These habits all raise the levels of low density lipoprotein (LDL), or bad cholesterol and decrease levels of high density lipoprotein (HDL), or good cholesterol. But lifestyle alone does not explain the whole picture.

The stress hormone cortisol has to be made or synthesized. The first ingredient of cortisol is cholesterol. When exposed to chronic stress, cholesterol levels increase to make more cortisol. But not all cholesterol becomes cortisol! People at risk of developing high cholesterol (e.g. family history) with unhealthy lifestyle and who are chronically stressed are at greatest risk of health problems.

Insulin Resistance and Type II Diabetes

Insulin is a hormone that carries a message that lowers blood sugar levels and helps us to store energy for future use.

The receivers of messages in our body are called receptors. In type II diabetes, the message carried by insulin is not understood by the receptors and blood sugar levels remain high.

Normally, when cortisol levels rise, insulin secretion stops. After all, we need all the energy we can get! Sugar fuels our muscles and brain. So with lower levels of insulin, blood sugar levels can remain high enough to provide us with the energy we need. Our stress response system has a fail-safe just in case we still have insulin kicking around. Stress hormones make sure that our cells do not respond to any remaining insulin in our system.

If we are chronically stressed, then our insulin levels can remain low and our blood sugar levels can remain high. On top of that, our cells can become almost totally resistant to insulin.

Truncal Obesity

Cortisol first and foremost maintains energy balance. When we expend energy (i.e. use up calories), our body needs to replace the energy lost. Cortisol carries this message: refuel!

Now, the brain and cortisol are always out to protect us. When we are chronically stressed they will ‘help us out’ by making it easier to get at our stored fuel (i.e. our fat tissue). So they begin storing energy in easy-access areas, such as our gut or trunk. The end result is truncal obesity or fat around our midsection.

The unfortunate thing is that our brain and stress response system do not know the difference and take for granted that we have used up the energy. Our brains have not changed much since we were hunter-gathers chasing mammoths, so we react similarly to the stressors of the modern world!

These are but a few examples of how stress hormones are vital to our health. The take home message here is that our body and brain maintain their normal functioning (homeostasis) through the delicate and precise interactions between many systems.

The stress response system and its end product cortisol are key players in these interactions. When the cortisol system becomes deregulated, it affects all other systems that depend on its integrity to function.