Why you should know about Insulin

Insulin plays an important part of metabolic processes in your body. It's a hormone released by the pancreas' beta cells to utilise blood glucose (sugar) into energy for your body, or to be stored as glycogen in your muscles and liver. You need insulin for protein synthesis in your muscles for repair and recovery. It also regulates your blood sugar level when it's too high (hyperglycemia) by stimulating Glycolysis (utilising Glucose for energy) and Glycogenesis (storing glucose into the muscle and liver as glycogen).

Insulin can be taken to help with Type 1 and Type 2 diabetes, where not enough insulin may be produced to draw glucose from the blood to your cells (Type 1), or the already made insulin isn't effective enough to transport glucose into your cells (known as Insulin resistance).

Insulin Resistance

Insulin Resistance occurs when the cells can't absorb glucose from the blood, and a build up of blood glucose occurs. If the pancreas isn't able to produce enough Insulin to overcome this excess, then this increases the risk of type 2 diabetes. Obesity, high blood pressure and smoking can all lead to Insulin Resistance. Keeping an active lifestyle and increasing physical activity reverses the effects of Insulin Resistance.

What is Glucagon

Now we can't talk about Insulin without talking about Glucagon as they are so closely related. Also produced in the pancreas, Glucagon is a hormone produced in the alpha cells which surrounds the beta cells that produce insulin. Glucagon prevents blood sugar levels dropping too low (hypoglycemia) by stimulating Glycogenolysis (converting stored glycogen in the liver into glucose into the blood stream) and Gluconeogenesis (generating glucose from protein). Glucagon release is stimulated not only by low blood sugar levels, but also by meals high in protein and Adrenaline.

To optimise blood sugar levels, there has to be a balance of Insulin and Glucagon levels. When you are well fed, Insulin is the dominant hormone, and your body will store excess energy. When in starvation or fasting phases, Glucagon then becomes the dominant hormone. A constant battle of balance occurs between the two in order to keep your body fuelled in all stages.

There are a few other hormones which are involved in the control of blood sugar levels.

Amylin, GIP & GLP-1 are hormones released to regulate insulin levels:

• Amylin is a hormone also produced by the beta cells of the pancreas (along with Insulin). It's functions are to decrease Glucagon levels, decrease the Liver's glucose production and promotes satiety so you feel full for longer

• Glucose-dependent insulinotropic polypeptide (GIP) and Glucagon-like peptide-1 (GLP-1) are incretin hormones, meaning they are hormones produced by the intestines and influence blood glucose. They signal the beta cells to increase insulin production and the alpha cells to reduce glucagon production. GLP-1 also promotes satiety

Epinephrine (Adrenaline), Cortisol, and Growth Hormone are hormones released to regulate Glucagon levels. They are referred to as "stress hormones" as they raise blood sugar levels:

• Epinephrine, more commonly known as Adrenaline is secreted from the adrenal glands and promotes Glycogenolysis, where the Liver converts glycogen to glucose to be released into the blood

• Cortisol is also generated from the adrenal glands and acts against the actions of Insulin. Known as your human alarm clock, when Cortisol levels are high due to stress, you become insulin resistant. This in turn allows glucose to build up into your blood and cells become resistant to Insulin

• Growth Hormone is released from the pituitary gland in the brain and causes resistance to Insulin actions on your cells

To summarise:

• Insulin is released when blood sugar levels are too high, and is needed for utilisation of glucose into energy, glycogen storage and protein synthesis

• Insulin resistance occurs when cells can't absorb glucose from blood and your pancreas is unable to produce enough insulin to counteract this, leading to diabetes

• Glucagon is released when blood sugar levels are too low and releases glycogen from the liver into glucose into blood for your cells to use

• There's a constant need for balance between Insulin and Glucagon in order to maintain your body's blood sugar levels and energy levels when eating and fasting

• Amylin, GIP, GLP-1, Epinephrine, Cortisol and Growth Hormone are all secondary hormones which assist in Insuline or Glucagon production