By Rachel Davies, Nutritionist
It would be easy to believe that alcohol helped you to sleep better because of its sedative effect. In fact, many people enjoy an evening drink to unwind after a long day, believing that alcohol helps them relax and drift off to sleep more easily. However, the reality is that alcohol significantly disrupts the quality of sleep, leaving you feeling fatigued and less refreshed the next day. In alcohol dependence, estimated rates of insomnia vary from 36-91%.
If you find yourself reaching for a nightcap to help you sleep, understanding how alcohol impacts sleep cycles, sleep hormone regulation and overall health might make you reconsider your nighttime habits. In this blog we will explore the ways in which alcohol impacts sleep and revisit healthier ways to support better quality sleep.
How Alcohol Affects Sleep Stages
Sleep is a complex process consisting of several stages, including light sleep, deep sleep and rapid eye movement (REM) sleep. We cycle through these stages throughout the night with 4-6 full cycles lasting around 90 minutes each. An optimal sleep pattern would involve progressively longer REM sleep periods. REM sleep is especially important for cognitive function, memory consolidation and emotional regulation. Alcohol disrupts this natural progression and optimal ‘sleep architecture’ in several ways:
Shortened Sleep Onset – Alcohol initially makes you feel drowsy, so you may fall asleep faster. This is why many people perceive it (and use it) as a sleep aid.
Increased Deep Sleep Early in the Night – The sedative effect of alcohol promotes deeper sleep in the first half of the night. The body then compensates for this in the second half of the night with less deep sleep, and longer stages of light sleep from which it is easier to wake up. Essentially alcohol disrupts our sleep architecture such that we are not getting optimal rest.
Disrupted REM Sleep – Alcohol suppresses REM sleep, which is vital for brain function and emotional processing. This means you wake up feeling less rested, even if you’ve slept for an adequate number of hours. Research has shown that this becomes more pronounced the more you drink.
Frequent Nighttime Wakings – As the body metabolises alcohol, sleep becomes more fragmented. This leads to frequent mini-awakenings, making it harder to maintain deep sleep.
Early Wake Up – Alcohol can disrupt the body’s circadian rhythm, leading to early wake ups and difficulty falling back asleep.
Diuretic Effect - Alcohol has a diuretic effect which can mean you wake more frequently in the night to use the toilet.
Alcohol’s Impact on Sleep Hormones and Circadian Rhythm
Our circadian rhythm, or sleep-wake cycle, is regulated by key hormones such as melatonin and cortisol. Alcohol interferes with these essential hormones in several ways:
Reduced Melatonin Production – Melatonin is the hormone responsible for regulating sleep. Studies show that alcohol consumption before bed can suppress melatonin levels by up to 20%, potentially making it harder to fall and stay asleep.
Increased Cortisol Levels – Alcohol consumption can activate the Hypothalamus- Pituitary - Adrenal (HPA) Axis which will raise cortisol, the body’s main stress hormone. Elevated nighttime cortisol disrupts sleep and can contribute to restlessness or night sweats.
Altered Body Temperature – Alcohol can cause changes to body temperature regulation, leading to overheating during the night and contributing to night-time waking.
Alcohol, Sleep Apnea, and Snoring
If you snore or suffer from sleep apnea, alcohol can make these conditions worse:
Relaxation of Airway Muscles – Alcohol relaxes the muscles in the throat, increasing the likelihood of airway collapse and snoring.
Worsened Sleep Apnea – Those with sleep apnea experience frequent breathing interruptions during sleep. We wrote a blog all about sleep apnea here. Alcohol exacerbates this by making the airway more prone to collapse, leading to more severe episodes of oxygen deprivation. Alcohol consumption raises a person's apnea-hypopnea index (AHI), indicating more frequent pauses or restrictions in breathing per hour during sleep.
The Consequences of Alcohol-Disrupted Sleep
Even if you sleep for a full eight hours after drinking alcohol, the sleep is often poor in quality. The consequences the next day can include:
Daytime Fatigue – Fragmented sleep results in lower energy levels, making it harder to focus and perform at your best.
Poor Nutrition Choices - After a bad night's sleep, it can be all-too-tempting to reach for 'quick fix' energy boosts, such as biscuits and chocolate.
Reduced Cognitive Function – Poor REM sleep can impair memory, cognition and emotional regulation.
Weakened Immune Function – Sleep is essential for a strong immune system. Chronic alcohol-induced sleep disruptions can leave you more vulnerable to illness.
Increased Stress and Anxiety – Poor sleep exacerbates stress and anxiety, leading to a vicious cycle where people rely on alcohol to relax but ultimately worsen their overall well-being.
How to Improve Sleep Without Alcohol
If you’re struggling with sleep and rely on alcohol as a sedative, it’s time to take back control of your sleep by getting these fundamental habits in place:
Create a Relaxing Bedtime Routine – Engage in activities that calm the nervous system and promote relaxation, such as reading, meditation, or taking a warm bath.
Limit Alcohol Intake – If you do drink, try to do so earlier in the evening and in moderation to allow your body enough time to metabolise the alcohol before bed.
Optimise your sleep environment – Keep your bedroom cool, the lights dim, and free from distractions like phones or laptops.
Get outside in the first hour of waking – This helps to set your circadian rhythm and help you feel energised for the day ahead.
Exercise regularly – Physical activity helps regulate sleep, but avoid intense workouts too close to bedtime.
Manage stress – Practice relaxation techniques such as deep breathing, journalling or mindfulness to help reduce stress levels.
Be mindful of caffeine intake - Caffeine has a half life of 5-6 hours so that 4pm flat white might be impacting the quality of your sleep. Stick to no more than two caffeinated beverages per day and not after lunchtime.
Consider a sleep-supporting supplement such as Sleepee - Sleepee is a combination of 11 natural ingredients that helps you fall asleep and stay asleep by naturally boosting the body’s melatonin levels over time.
While a drink before bed may seem like a shortcut to relaxation, it comes at the cost of your sleep quality. Alcohol disrupts sleep architecture, interferes with key hormones, and leaves you feeling exhausted the next day. By making small changes to your nighttime routine, you can improve sleep quality naturally and wake up feeling refreshed and ready to tackle the day ahead.
This blog is written by Nutritional Therapist Rachel Davies. Rachel is registered with the BANT (British Association of Nutrition and Lifestyle Medicine) and the CNHC (Complementary and Natural Healthcare Council). She continually attends CPD training to further her expertise and keep abreast of the fast moving field of nutritional science.
Note: This article is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.