Cortisol - don't blame me for the fat!

Here's a quick blog post about cortisol, that has every right to be stressed!

Cortisol is often blamed for an increase in stomach adipose tissue – fat around our stomachs. But, cortisol does NOT store fat. It has been wrongly accused. Cortisol actually releases fatty acids from our adipocytes (releases fat for energy from our fat stores) so we can use them as energy. Contrary to popular belief cortisol doesn’t store fat – it actually releases it!

Cortisol joins lactic acid and cholesterol as being wrongly accused. Jokingly, on my Facebook feed my friend Tom Barbieri has suggested they should form their own support group for the wrongly hated.

So what is cortisol, and why does it get wrongly accused?

Cortisol is a stress hormone, released into the blood by the adrenal glands. Cortisol can act on nearly every cell in the body. Cortisol acts to raise our metabolic rate, acts as an anti-inflammatory, controls salt and water balance, and influences blood pressure. It also releases energy sources into our blood for use.

These energy sources are glucose and fatty acids. Glucose is released from the liver. Muscle is also broken down into amino acids, and these are converted again to glucose. Fatty acids (fat) become released from adipocytes (fat cells). All of these energy substrates enter our blood stream. This energy allows us to act in the face of a stressor.

With the stressor removed, cortisol falls, and the energy release (from cortisol) stops. Yet, if we don’t use the energy floating around our blood it still has to go somewhere. The muscle and liver stores become replenished with the excess glucose. If these stores are full the glucose is converted and stored in our adipocytes, our fat cells. Any excess fatty acids become absorbed and stored once more in our adipocytes. This may result in more ‘fat’ being stored than before, due to the increase in glucose thanks to the breaking down of the muscles. The effect of this however is nominal, and this is in the absence of cortisol, not because of it.

Cortisol is naturally released in the morning, when we are in a fasted state, at times of stress, and during exercise. But cortisol is most commonly discussed in respect to stress.

Stress affects us psychologically and physiologically. Stress is a major causation of an increase in fat storage. But that isn’t down to cortisol. Cortisol does a good job, ensuring we have energy to respond to threats. It doesn’t deserve the bad press.