Latest news with #adrenalglands
Yahoo
21-07-2025
- Health
- Yahoo
Expert shares the surprising role cortisol plays in our sleep — and why it's just as important as melatonin
When you buy through links on our articles, Future and its syndication partners may earn a commission. You've likely heard of cortisol as 'the stress hormone,' the one that spikes when your boss drops a big project in your inbox or when you're running late and stuck in traffic. But cortisol is more than just your internal 'let's get out of here' system; it's also a key player in how your body regulates sleep. This sleep hormone follows a natural 24-hour rhythm that helps you wake up feeling alert and allows the body to properly wind down at night. When it's not functioning properly, your sleep may suffer. We connected with Andrew Franklyn-Miller, MBBS, PhD, Chief Medical and Innovation Officer at Nuritas, and reviewed research on the relationship between sleep and cortisol, to share how cortisol plays a role in our explore the science behind how cortisol interacts with melatonin and your body's circadian rhythm, how it aids rest or hinders it and expert-backed ways to keep cortisol in check throughout the day so you can reap more, better sleep. What is cortisol? Cortisol is a glucocorticoid hormone produced by the adrenal glands. It's related to quite a few responses in the body, from handling the body's stress response, to regulating inflammation, immune function and impacting metabolism. It's also integral to regulating the body's sleep-wake cycle, interacting with hormones like melatonin and aligning with the circadian rhythm—the natural times your body wakes up and falls asleep. 'Cortisol promotes alertness by mobilizing energy stores, increasing blood glucose, and enhancing cognitive function during waking hours,' says Dr. Franklyn-Miller. Why is cortisol important for sleep? Cortisol is essential for a healthy sleep-wake cycle because its peaks and dips impact how quickly you fall asleep, when you wake up the next morning and may even impact your sleep cycles as you snooze. When cortisol is disrupted, for example, if it's surging in the evenings due to psychological stress, it can impact sleep quality, making it more challenging to fall asleep and stay asleep through the critical sleep stages, according to this study. Cortisol helps you wake up in the morning Think of cortisol as part of your body's natural 'get up and go' response. According to research, the cortisol awakening response (CAR), a physiological response that results in a sharp rise in cortisol levels within 30 to 45 minutes of waking, prepares the body for daily activities by boosting metabolism and vigilance. Cortisol levels peak in the early morning and decline throughout the day, reaching their lowest point at night to facilitate sleep onset and maintenance. 'While cortisol amplifies metabolic readiness, neural networks and neurotransmitters like the neurotransmitter orexin are primary in initiating and sustaining wakefulness,' says Dr. morning cortisol levels can contribute to difficulty waking and feelings of lethargy, making it feel particularly tough to get out of bed in the morning. Cortisol helps you wind down in the evening Cortisol and melatonin are the seesaw hormones that help with sleep. Cortisol is suppressed at night when melatonin is high, allowing for restful sleep. As morning approaches, rising cortisol levels inhibit melatonin production, making wakefulness easier, so you feel less groggy in the morning. 'Dysregulation, such as stress-induced cortisol elevation at night, can suppress melatonin synthesis, delaying sleep onset or reducing sleep depth,' says Dr. Franklyn-Miller. Cortisol can impact your sleep cycles Tiny pulses of nocturnal cortisol still spike during the night, especially between sleep stages, particularly during rapid eye movement (REM) sleep or brief awakenings, says Dr. Franklyn-Miller. In healthy sleepers, these blips act as micro-check-ins, making sure your body temperature, blood sugar, and memory-storage tasks stay on track. 'However, excessive spikes, often triggered by stress, anxiety, or sleep disorders like insomnia, can disrupt sleep architecture by reducing deep slow-wave sleep or fragmenting REM sleep,' he says. Those middle-of-the-night disruptions negatively impact sleep quality, causing fatigue and impairing function during the day. Not getting enough sleep has been related to higher levels of cortisol. Can cortisol disrupt sleep? Yes, cortisol changes can disrupt sleep. If it's not higher in the morning and lower in the evening, it can impact your ability to fall asleep and stay asleep. Low morning levels of this stress hormone, cortisol, can contribute to difficulty waking and feelings of lethargy. The CAR is critical for mobilizing energy and promoting alertness, and its blunting, as seen in adrenal insufficiency or chronic fatigue syndrome, can lead to sluggishness and trouble getting out of bed, Dr. Franklyn-Miller says. Other factors, such as poor sleep quality or circadian misalignment, may exacerbate this. If you're under chronic stress, the body's fight-or-flight response (hi, cortisol) doesn't power down as it should. That can have a direct impact on your ability to fall asleep, stay asleep, and wake up feeling rested. How to regulate cortisol levels for better sleep As of right now, many popular wearables can't detect cortisol levels in sweat to tell you if that hormone is operating optimally or not. But you can try to help regulate cortisol by supporting healthy circadian rhythm functioning, Dr. Franklyn-Miller suggests. Try these tips:Get light exposure after waking in the morning. Aim for 10 to 30 minutes of natural sunlight or bright light (10,000 lux) within an hour of waking to boost the CAR and suppress melatonin so you feel more awake and alert. Stick with a consistent sleep schedule. There's a reason you read this tip in most of our sleep articles: Because it works. Regular bed and wake times stabilize circadian rhythms, ensuring low nighttime cortisol and a robust morning peak. Practice stress management. Aim for at least 10 minutes daily to reduce chronic stress and lower nighttime cortisol, suggests research in the Journal of Clinical Endocrinology & Metabolism (2005). Better stress management can result in falling asleep faster and staying asleep. Eat a balanced diet. Try to keep meals lower in carbohydrates closer to bedtime to stabilize blood sugar and help prevent cortisol spikes from hypoglycemia, suggests Dr. Franklyn-Miller. Avoiding late-in-the-day caffeine or heavy meals can help with evening cortisol remaining low. Be mindful of exercise timing. Try to give your body a few hours to unwind after an evening exercise sesh if that's the only time you can squeeze it in. Moderate exercise in the morning or afternoon supports healthy cortisol rhythms, while intense evening workouts may elevate nighttime cortisol, according to the Journal of Neuroendocrinology (2003). Limit blue light at night. Reducing screen time can help enhance melatonin and suppress cortisol. Use relaxation techniques before bed. Performing calming activities like reading or gentle yoga can lower evening cortisol, focusing on increasing heart rate variability and parasympathetic nervous activity, promoting restful sleep, according to the Journal of Clinical Endocrinology & Metabolism (2005).
Telegraph
13-07-2025
- Health
- Telegraph
The nine foods to eat to lower your cortisol, according to a nutritionist
Stress is unavoidable. We wake up to the sound of drilling right outside our bedroom window, we miss our train or bus, or maybe we're stuck in traffic – no matter the scenario, stress seems to be a part of everyday life. It is no surprise, then, that cortisol appears to be the leading topic of many hormone health conversations with the term 'cortisol detox' populating social media platforms. But what exactly is cortisol? Cortisol is a hormone produced by our adrenal glands that plays a crucial role in a lot of our bodily functions, including our sleep-wake cycle, salt and water balance, immune function and stress response. 'Cortisol affects the entire body, think of it like the fog horn hormone,' says Hannah Alderson, a BANT registered nutritionist, hormone specialist, and author of Everything I Know About Hormones. 'It wakes you up, and saves your life in a dangerous situation, like being chased by a bear,' she explains. 'It increases blood sugar when needed, and regulates your metabolism – it's essential to health. But too much is a problem, chronic longer-term elevation of cortisol can drive disease, endocrine disorders, obesity – and the notorious belly fat.' Why too much cortisol becomes a problem However, when cortisol levels develop an irregular pattern, or too much or too little is produced, side effects can occur, including fatigue, poor sleep, dizziness and mood swings. 'The problem is when cortisol levels are elevated for too long,' says Nichola Ludlam-Raine, a registered dietitian and author of How Not to Eat Ultra-Processed. A long period of too much cortisol can also lead to heart disease, stroke, Type 2 diabetes and Cushing's syndrome. For mid-lifers, high cortisol can also impact muscle mass, adds Ludlam-Raine. 'It can promote the breakdown of muscle and it can also inhibit muscle growth.' Cortisol can also lead to weight gain, particularly around the belly. Studies have found that consistently high levels of cortisol cause weight to be distributed in the abdomen, particularly in women. This is because elevated cortisol triggers a fight/flight response which drives a glucose spike to ensure you have energy for the situation you're in. When that energy isn't used, it's stored around the abdomen. How can we lower our cortisol levels through diet? The obvious solution to lowering cortisol is to reduce stress. For busy mid-lifers who don't have the time to practice breathwork or meditation, a cortisol diet might be the best way to lower levels. Cortisol is closely linked with our gut health, and studies have shown that having high levels of good gut bacteria can help regulate cortisol levels. Similarly, an unhealthy gut can drive up cortisol and inflammation, says Ludlam-Raine. So it's important to have a healthy gut to keep your cortisol levels stable. 'Blood sugar regulation is also extremely important,' Ludlam-Raine adds. 'Spikes and crashes from high-sugar or ultra-processed diets can increase cortisol as your body tries to stabilise energy levels.' Zoe Jane Hindle, a functional wellness practitioner, says: 'In the morning, you need to make sure you're eating a proper meal – having just a pastry is not enough. When your blood sugars go up, you will crash because you're on a blood sugar roller-coaster without even realising it.' If you're thinking about tweaking your diet to lower your cortisol levels make sure you avoid things like 'bulletproof coffee ' which is often peddled as being a way to reduce it. The drink mixes coffee with grass-fed butter or ghee and medium-chain triglyceride (MCT) oil, and promises boost energy levels and improve focus. However, it may cause more harm than good because of caffeine which can increase cortisol production. Eating a lot of saturated fats (found in butter and ghee) can also increase cortisol. The other fad worth swerving is Ashwagandha, an African plant which is popular in the wellness community for boosting calm and lowering stress levels. As promising as it may appear, those considering taking Ashwagandha should do their research beforehand – it's not a one-size-fits-all solution, and it doesn't always make things better. It also may interfere with certain medications such as blood-pressure lowering medications, and ones that treat diabetes. Prioritise whole, minimally processed foods, eat regularly to avoid blood sugar dips and stay hydrated, says Ludlam-Raine. A balanced plate that includes fibre, healthy fats, protein, and complex carbs helps keep blood sugar stable and supports your gut. Nine foods to lower your cortisol Here, Ludlam-Raine shares her top nine foods to help lower your cortisol levels: 1. Yoghurt A serving (150g) of plain, natural yoghurt with live cultures acts as a probiotic, and research suggests that some probiotics may reduce cortisol levels. This can be the result of probiotics helping to reduce gut inflammation and, in turn, lower cortisol. 2. Walnuts Walnuts contain omega-3 fatty acids as well as fibre and unsaturated fats, which support inflammation and brain health. One study found that regularly consuming omega-3 does reduce overall cortisol. A handful of walnuts (or 28g) is a good starting point. 3. Olive oil Extra-virgin olive oil has more evidence of managing stress than regular olive oil – it's higher in unsaturated fats and antioxidants which help lower inflammation and therefore stress. You need to make sure that you're using extra virgin olive oil every time you cook and aim for one to two tablespoons per day. 4. Tinned mackerel or sardines We should be aiming for two portions of fish a week, one of which should be an oily fish. Oily fish contains o mega-3 which reduces inflammation and cortisol levels. Mackerel also contains niacin and selenium which is good for balancing hormones. Sardines contain vitamin B12 which, according to a 2019 review, improves our body's ability recover after stress. 5. Oats Oats contain tryptophan – an amino acid that may help increase serotonin, which helps to balance stress levels. Oats are also high in fibre and can stabilise blood sugar levels by gradually releasing glucose into the bloodstream. A typical serving is 40g. 6. Cashew nut butter Make sure it is 90 to 100 per cent nut butter. This is a great source of protein, unsaturated fats and micronutrients, including magnesium which can help calm the nervous system and regulate cortisol production. Two tablespoons of cashew butter have around 60mg of magnesium, around 20 per cent of your daily magnesium intake. 7. Kiwi Kiwis are a great source of vitamin C; one serving (two kiwis) provides 137mg which is twice the amount of vitamin C in an orange. Vitamin C helps regulate the adrenal glands which control cortisol production. Kiwis (with the skin left on) are also rich in fibre which can help boost your gut health. 8. Broccoli and spinach Green vegetables are incredibly important when it comes to regulating cortisol levels because of their high levels of magnesium, folate and other vitamins that can help to regulate stress responses. Broccoli is another good source of vitamin C and also contains sulforaphane which has anti-inflammatory properties. Alternatively, 100g of spinach contains 75mg of magnesium, which makes spinach the vegetable with the highest amount. 9. Red wine (yes, really!) While alcohol in general isn't recommended, for those who do drink, red wine is richer in flavonoids than other drinks such as white wine or spirits. You can also find flavonoids in dark chocolate, berries and green tea. Studies reveal that flavonoids can help reduce inflammation, while one 2019 study looked at the effects on eating flavanoid-rich dark chocolate for four weeks and found that the flavonoids reduced salivary cortisol levels. The risks of a cortisol detox diet Ludlam-Raine does stress that any kind of 'cortisol diet' should be treated more as a lifestyle pattern than a strict diet. Being too rigid with any diet can lead to increased risk disordered eating. 'It's a lose-lose situation – especially if someone is trying to lose weight and they are extremely stressed.' Keay suggests taking a holistic approach to lowering cortisol: for example, limit screen time in the morning and try and get some natural light as soon as you get up. 'When we are on our phones first thing in the morning and last thing at night, we mess with our day and night signals,' she says. 'Get outside – we shouldn't be fearing the sun. Daylight is calming for our nervous system and stress responses. To make the outing even more productive, catch up with a friend or spend time with a loved one. The bonding hormone, oxytocin, helps to regulate cortisol levels.'
