News that actor Shin Ha-kyun has recently quit coffee and alcohol has garnered significant attention. During an appearance on the YouTube channel 'DdeunDdeun', he shared his secret to achieving deep sleep, which is none other than giving up coffee and alcohol. Shin Ha-kyun revealed, "Lately, I haven't been drinking coffee for better sleep. I also haven't had alcohol for 5 months now." He emphasized, "As a result, I'm sleeping so much better." So, does moderating coffee and alcohol, like Shin Ha-kyun, actually help with deep sleep?

Why Quitting Coffee Can Lead to Deep Sleep

The claim that quitting coffee can lead to deep sleep has medical backing. Caffeine in coffee is a stimulant that activates the central nervous system, interfering with the action of adenosine, which induces drowsiness in the brain when fatigue builds up. This can lead to difficulty falling asleep or not sleeping deeply, even when feeling tired.

The American Academy of Sleep Medicine recommends avoiding caffeine intake in the afternoon or evening as part of healthy sleep habits. For those particularly sensitive to sleep, it's advisable to reduce not only coffee but also other caffeinated beverages. It's best to limit consumption of black tea, cola, energy drinks, and chocolate from the afternoon onwards. Studies have shown that caffeine consumed even 6 hours before bedtime can disrupt sleep.

Alcohol and Deep Sleep: Truths and Misconceptions

Many people believe that drinking alcohol can aid in deep sleep. However, this is not the case. While alcohol may initially induce drowsiness, making it seem like you fall asleep easily, it actually degrades sleep quality in the latter half of the night. It disrupts the normal sleep architecture, increases light sleep and frequent awakenings, and reduces REM sleep, which is crucial for memory and emotional processing. A review published in 2025 reported that while alcohol may reduce the time it takes to fall asleep, it can subsequently interfere with REM sleep.

Furthermore, alcohol can relax the muscles around the throat, potentially worsening snoring and sleep apnea. This is why you might feel unrefreshed even after sleeping when you've consumed alcohol the night before.

Additional Tips for Deep Sleep

For deep sleep, it's advisable to avoid not only coffee and alcohol but also late-night overeating. Heavy meals should be avoided a few hours before bedtime, as a full stomach or indigestion can make it difficult to fall asleep. Spicy and fatty foods can slow digestion and cause acid reflux, both of which can disrupt sleep. Therefore, it's important to develop habits that avoid late-night consumption of ramen, fried chicken, deep-fried foods, spicy snacks, chocolate, and caffeinated beverages.

• Go to bed and wake up at consistent times.
• Get light exercise and expose yourself to sunlight during the day.
• Reduce smartphone use and work before bed.
• Keep your bedroom dark and quiet.

These habits can help induce deep sleep. Like Shin Ha-kyun's choice, why not aim for better sleep through healthy lifestyle habits?