Drinking coffee in the evening is also often reported to have a negative impact on sleep due to caffeine's natural stimulating effects. But recent research published in the journal Sleep revealed that drinking coffee within four hours of bedtime does not affect sleep at all.
A team of American researchers found a strong link between the evening use of alcohol and nicotine and insomnia, one of the most common sleep disorders in adults. According to their findings, smoking at night resulted in a 42-minute reduction in overall sleep. Drinking an alcoholic drink before bed also led to sleepless nights.
To evaluate the effects of caffeine, nicotine and alcohol on sleep, researchers studied 785 African-Americans in their natural environments over the course of 5,164 days. None of the participants suffered from preexisting sleep disorders.
The researchers measured their estimated sleep duration, sleep efficiency and wake after sleep onset (WASO) using a wristwatch-like sensor. WASO is a metric used in sleep studies to determine how fast a person wakes up after a period of sleep.
The team also studied the participants' entries in their sleep diaries. The diaries recorded their consumption of alcohol, caffeine and nicotine within four hours of bedtime.
About 40 percent of the group reported drinking coffee at night, but the researchers found that caffeine had no significant effect on their sleep duration.
On the other hand, participants who smoked, vaped or drank within four hours of going to bed experienced a negative impact on their sleep, even when the researchers controlled for age, gender, stress and other factors that can affect sleep.
In particular, people who indulged in an alcoholic drink before bed experienced sleepless nights. Smoking and vaping at night, on the other hand, led to a 42-minute reduction in overall sleep.
In addition, nicotine use has also been found to be associated with insomnia more than alcohol consumption.
Based on their findings, the researchers thus concluded that consuming alcohol and nicotine within four hours of bedtime led to sleep disturbances and sleepless nights more than drinking coffee. These findings underscore the importance of restricting alcohol and nicotine consumption at night.
According to lead author Christine Spadola, their research is one of the largest longitudinal studies that examined the evening consumption of alcohol, caffeine and nicotine. Spadola added that their findings can be enlightening for African-Americans in particular, most of whom suffer from sleep disorders more than other populations.
Sleep is a vital component of our overall health and well-being. Without adequate sleep, we become at risk of chronic diseases and health complications that can shorten our lifespan. (Related: Sleep it off: Research explains why sleep is so important for your immune system.)
Besides limiting alcohol consumption and nicotine use, here are six other tips for sleeping better at night:
Learn more about sleep and common sleep disorders at Health.news.