Cortisol and insulin resistance

Cortisol is produced by the adrenal glands and is released in response to stress — whether that's physical stress, such as illness, or emotional stress, such as anxiety. It shifts the body into "fight-or-flight" mode by releasing energy so we can respond quickly to threats.

Cortisol raises blood sugar by releasing glucose from stored glycogen in the liver and by breaking down muscle tissue into amino acids, which are then converted into glucose. This process ensures there is sufficient energy available to act quickly in stressful situations.

What is insulin resistance?

Insulin is a hormone produced by the pancreas that helps regulate blood sugar. It enables cells to take up glucose from the blood and use it for energy or store it as fat.

Insulin resistance occurs when cells become less responsive to insulin. As a result, glucose cannot be effectively absorbed from the blood, leading to higher blood sugar levels. To compensate, the pancreas produces more insulin — which can ultimately lead to elevated insulin levels in the blood.

Over the long term, insulin resistance can lead to the development of type 2 diabetes, weight gain, and other metabolic problems.

How cortisol worsens insulin resistance

Chronically elevated cortisol levels can contribute to the development of insulin resistance in several ways:

• Elevated blood sugar: Cortisol increases the amount of glucose in the bloodstream by breaking down glycogen in the liver and converting muscle tissue into glucose. As a result, blood sugar remains high, driving increased insulin production by the pancreas.
• Reduced insulin sensitivity: Chronic stress and elevated cortisol can reduce the insulin sensitivity of cells. This means cells respond less effectively to insulin, leaving glucose circulating in the bloodstream.
• Increased abdominal fat: High cortisol levels have been linked to an increase in visceral fat — the fat that accumulates around the organs. This type of fat is particularly dangerous because it raises the risk of metabolic conditions including insulin resistance and cardiovascular disease.
• Disrupted energy balance: Cortisol can also stimulate appetite and lead to overeating, particularly of high-sugar and high-fat foods. These foods raise blood sugar and require more insulin to process, deepening the vicious cycle of insulin resistance.

The consequences of chronic stress

The combination of chronically elevated cortisol and insulin resistance can lead to a range of health problems:

• Type 2 diabetes: Prolonged insulin resistance increases the risk of developing type 2 diabetes, a condition in which the pancreas eventually becomes exhausted and can no longer produce sufficient insulin.
• Weight gain: Chronic stress can lead to weight gain — especially around the abdomen — which further increases insulin resistance.
• Cardiovascular disease: Elevated cortisol and insulin levels can contribute to the development of atherosclerosis, high blood pressure, and other cardiovascular conditions.

What can you do to manage cortisol and insulin resistance?

Fortunately, there are several strategies you can use to lower cortisol levels and prevent or reverse insulin resistance:

• Stress management: Techniques such as meditation, yoga, breathing exercises, and getting enough sleep can help lower cortisol levels and reduce the impact of stress on the body.
• Healthy nutrition: Eat a diet rich in fibre, healthy fats, and lean protein, and avoid sugary and processed foods. This helps keep blood sugar stable and improves insulin sensitivity.
• Regular exercise: Physical activity — especially strength training and aerobic exercise — can help raise insulin sensitivity and lower cortisol levels. Regular movement also supports weight management and reduces visceral fat.
• Sleep optimisation: Sufficient, quality sleep is essential for regulating cortisol and insulin levels. Aim for 7–9 hours per night and maintain a consistent sleep schedule.
• Social support: Strong social connections and a supportive network can help reduce stress and improve overall mental health.

Conclusion

The relationship between cortisol and insulin resistance highlights how important it is to keep both physical and emotional health in balance. By managing stress effectively, eating well, exercising regularly, and getting enough sleep, you can reduce the negative effects of cortisol and improve your insulin sensitivity. These steps are essential for maintaining a healthy metabolism and preventing chronic conditions such as type 2 diabetes and cardiovascular disease.