Ever wondered why you feel a jolt of energy in the morning or why stress seems to disrupt your sleep at night? The answer lies in a little hormone called cortisol. Picture this: you’re preparing for a big presentation, your heart races, and you feel on edge. That’s cortisol in action, helping your body respond to stress.

Think of cortisol as your body’s built-in alarm system. It is the primary stress hormone, working with certain parts of the brain to regulate mood, motivation, and fear. Produced by the adrenal glands, triangle-shaped organs located on top of the kidneys, cortisol has several essential roles in maintaining health and homeostasis. Although often associated with stress, cortisol is crucial for numerous bodily functions.

The Vital Functions of Cortisol

Along with protein and fat metabolism, one of cortisol’s key roles is controlling inflammation. It acts as an anti-inflammatory agent, which is why synthetic corticosteroids like prednisone are prescribed for inflammatory diseases. Cortisol keeps the immune system in check, preventing overreactions that could damage the body’s own tissues and help prevent autoimmune diseases. However, chronically high cortisol levels can lower immunity by decreasing white blood cells and antibody formation. Whether these effects are “good” or “bad” depends on whether cortisol’s release is acute (brief and infrequent) or chronic (ongoing).

Too Much Cortisol

The hypothalamus-pituitary-adrenal (HPA) axis controls cortisol release naturally. Once cortisol levels are high enough, the HPA axis stops further production to maintain balance. Therefore, the cortisol levels are tightly regulated in the body and it’s difficult to have “too much cortisol” unless there is a pathological condition or a steroid drug is being ingested.
A nodule (mass) in your adrenal gland or a tumour in the brain’s pituitary gland can trigger your body to make too much cortisol. This can cause a condition called Cushing’s Syndrome. It can lead to rapid weight gain, skin that bruises easily, muscle weakness, diabetes, and many other health problems.

Too Little Cortisol or ‘Adrenal Fatigue’

“Adrenal fatigue” is a misleading term. Adrenal glands do not become “tired” but may produce less cortisol due to various physiological reasons. Proper diagnosis requires understanding the underlying mechanisms, such as adrenal insufficiency or suppression, rather than assuming adrenal fatigue. Low cortisol can result from adrenal insufficiency or suppression.
If your body doesn’t make enough of this hormone, you have a condition doctors call Addison’s disease. Usually, the symptoms appear over time. They include:

l Changes in your skin, like darkening on scars and in skin folds
l Being tired all the time
l Muscle weakness that grows worse
l Diarrhoea, nausea, and vomiting
l Loss of appetite and weight
l Low blood pressure

If your body isn’t making enough cortisol, your doctor may prescribe dexamethasone, hydrocortisone, or prednisone tablets.

Misconceptions and Realities

Contrary to popular belief, cortisol levels alone do not indicate stress or lifestyle quality. Individuals with stressful jobs might have perfect cortisol levels, while those with a seemingly stress-free life might have imbalanced levels. Cortisol levels must be assessed through lab testing, as perceived stress does not accurately reflect actual levels.

Cortisol and Exercise

An increase in cortisol during exercise is completely normal and expected. Cortisol’s functions during physical activity include increasing energy availability, heart rate, and blood pressure, serving as a compensatory mechanism to handle the physical stress induced by exercise.
This increase represents a normal, acute change in cortisol levels. However, a common misconception suggests that exercising for prolonged hours chronically spikes cortisol levels, thereby inhibiting muscle hypertrophy. In reality, the duration of exercise is highly individual and goal-dependent. Muscle hypertrophy is a process that occurs over time and is not significantly affected by short-term fluctuations in cortisol levels.

Cortisol and Weight

Excessive cortisol can lead to Cushing’s Syndrome, typically caused by adrenal or pituitary tumours or high doses of anti-inflammatory drugs. Symptoms include frailty, some abdominal obesity, a round face, purple stretch marks, and hip weakness.

Constantly elevated cortisol levels can cause excessive breakdown of muscles, skin, and bones, along with increased blood glucose and insulin levels. This can lead to fat gain in the tummy, face and neck. However, weight gain is primarily due to a positive energy balance, often coinciding with reduced physical activity during high-stress conditions and lifestyle-related disorders like type-2 diabetes.

It’s misguided to blame cortisol alone for belly fat. While high and sustained cortisol levels may lead to conditions that result in a caloric surplus, this usually comes with many warning signs and doesn’t happen overnight. High stress levels can lead to water retention, causing temporary weight gain or a bloated appearance, but this is different from gaining fat. Marketing gimmicks often promote supplements and programs claiming to reduce cortisol for weight loss. While higher physiological cortisol levels due to stress might slightly increase abdominal fat, reducing stress won’t directly cause weight loss. Instead, it can improve overall well-being, leading to healthier eating habits and better calorie balance.

Cortisol and the Sleep-Wake Cycle

Cortisol follows a diurnal rhythm, which aligns with the sleep-wake cycle. Here’s how it typically works:
l Morning Peak: Cortisol levels are highest in the early morning, around 7am to 9am. This spike helps wake us up and provides energy for the day.
l Gradual Decline: Throughout the day, cortisol levels gradually decrease.
l Evening Low: By the evening, cortisol levels are at their lowest, allowing the body to wind down and prepare for sleep.

This natural rhythm ensures that cortisol supports our daily activities and rest periods effectively. Quality sleep is crucial for maintaining the natural rhythm of cortisol. Lack of sleep, even for a single night, can cause a significant increase in cortisol levels the following evening. Prolonged sleep deprivation can lead to consistently high cortisol levels, which are associated with various health issues, including impaired cognitive function and an increased risk of cardiovascular diseases.

The Impact of Elevated Cortisol on Sleep

High cortisol levels, particularly in the evening, can interfere with the ability to fall asleep and achieve restorative sleep. Some of the effects include:
l Difficulty Falling Asleep: Elevated cortisol can make it hard to relax and fall asleep, leading to insomnia.
l Frequent Awakenings: High cortisol levels can cause disruptions during the night, resulting in fragmented sleep.
l Reduced Deep Sleep: Cortisol can interfere with the ability to enter deep, restorative sleep stages, which are crucial for physical and mental recovery.

Five Evergreen Strategies to Improve Sleep

Sleep hacks come and go, but these five principles of good sleep are nearly universally recommended by sleep experts and good sleepers alike:

1. Keep your sleep-wake schedule consistent. Wake at roughly the same time each day (including weekends) and hit the sack around the same time each evening.
2. Use a pre-sleep ritual. About 30 to 60 minutes before going to bed, get into wind-down mode. Turn off screens. Dim the lights. Relax with a bath, stretching, or time with a book. By doing the same behaviours each evening, you’ll train your brain to know it’s bedtime.
3. Avoid high-fat, high-calorie evening meals. Consume moderately sized meals no later than three hours before bedtime. Eating a heavy meal right before sleeping can lead to acidity in some.
4. Keep your room dark. If possible, make your bedroom as dark as possible or consider wearing a sleep mask. That way, you reduce interference from street lights or other lights in your environment, which can inhibit melatonin.
5. Limit screen time. Reduce exposure to screens and blue light before bedtime, as they can interfere with melatonin production and disrupt sleep.

Nutrimend is a diet consultancy clinic founded by Neha Patodia and Nupur Arya in 2015. They coach people on how to eat right so that they feel confident in their bodies and achieve their desired goals