You’ve likely heard that drinking coffee before bed hinders sleep, but new research shows that other lifestyle habits may affect quality rest, too.
A recent U.S. study on evening use of alcohol, caffeine and nicotine found that drinking and smoking within four hours of bedtime were associated with “increased sleep fragmentation.” This includes negative effects on sleep duration, sleep efficiency and wake after sleep onset.
Caffeine, on the other hand, wasn’t found to significantly impact sleep patterns.
“These findings support the importance of sleep health recommendations that promote the restriction of evening alcohol and nicotine use to improve sleep continuity,” the study’s authors wrote in health journal Sleep.
Led by a professor out of Florida Atlantic University (FAU), researchers tracked the habits of 785 African-American adults for over 5,000 days with wrist sensors and sleep diaries. Data showed that people who used nicotine and alcohol before bed “demonstrated worse sleep continuity than a night without these substances,” FAU said in a statement.
This was true even after controlling for factors like age, gender, level of education, having work the next day, depressive symptoms such as anxiety and stress.
Nicotine was the substance most strongly associated with sleep disruption, researchers found. For participants with insomnia, “nightly nicotine use was associated with an average 42.47-minute reduction in sleep duration.”
Past research on nicotine and sleep has found that smokers have more sleep issues than non-smokers, too. Other research has found that sleep loss may increase smoking.
Alcohol is also known to affect sleep quality. Previous research found that booze before bedtime may affect sleep, and the U.S. National Institute on Alcohol Abuse and Alcoholism says alcohol “has extensive effects on sleep and daytime sleepiness” and can cause sleep disturbance in healthy adults.
(A recent global report also found that no amount of alcohol is safe for our health.)
When it comes to caffeine, it’s important to note that the study’s researchers were not able to measure individual variations in caffeine sensitivity and tolerance. This means that coffee may affect some people more than others.
A standard cup of brewed coffee has around 130 milligrams of caffeine in it, and Health Canada advises healthy adults not to consume more than 400 milligrams (about three cups) a day.
Dr. Ahmed El-Sohemy, a professor in the department of nutritional sciences at the University of Toronto, previously told Global News that “50 per cent of the population… is a ‘slow’ metabolizer of caffeine,” meaning many folks may want to limit their intake to no more than two cups of coffee a day.
Since caffeine is a stimulant, drinking more than the recommended intake may lead to difficulties falling asleep or other issues, registered dietitian Andy De Santis previously told Global News.
“In some people who are sensitive to it, caffeine may lead to anxiety, insomnia and stomach issues,” De Santis said. “These people need to be mindful of their caffeinated coffee intake.”
Caffeine has a number of health effects on the body and brain.
Depending on how you consume it, caffeine could improve memory, boost athletic performance, and be good for the heart.
But too much of it may also cause irritation or anxiety.
Many of us can't start our day without a jolt of caffeine.
Various caffeinated drinks affect your health in different ways. Coffee itself seems to be associated with significant health benefits, including reduced cancer risk, improved liver function, and a lower risk for cognitive decline. But other caffeinated beverages like energy drinks have surprisingly high sugar levels, which may have negative health effects but.
But caffeine itself can do a lot, including boost athletic performance, improve memory, and — according to one recent review of studies — it may improve heart function.
The popular stimulant has both positive and negative effects. It makes most of us feel more alert, awake, and focused, but too much can also backfire.
It also affects a host of processes in our bodies, including our digestion, metabolism, and vision.
Here's what's really going on after you drink a cup of joe.
Caffeine is the most commonly used psychoactive drug in the world.
One of the things rarely mentioned about caffeine is that it is, in fact, a drug. In fact, it’s the most commonly used psychoactive drug in the world, which is probably why we don’t think about it as a drug.
Caffeine has psychoactive effects, and changes the way we feel and interact with the world around us. Yet think of how many of us can’t — or won’t — go through a day without it.
Harvard neuroscientist Charles Czeisler has hypothesized that caffeine, combined with electricity, allowed humans to escape natural patterns of sleep and wakefulness, breaking them free from the cycle of the sun. That change, he wrote in National Geographic, enabled the “great transformation of human economic endeavor from the farm to the factory.”
It makes us feel alert, at least for a while.
It’s normal to grow tired as the day progresses — our brains naturally produce more of a molecule called adenosine from the time we wake up until the time we go to sleep. Scientists think this helps us get to bed at night.
Caffeine hijacks this natural process by mimicking adenosine in the brain. It latches onto the receptors designed for adenosine, pushing them out of the way. As a result, we’re left feeling more alert and awake.
Eventually, however, adenosine wises up to caffeine’s act and makes new receptors for the sleep-inducing molecule to start latching onto again.
This is why your morning cup of coffee can suddenly turn into two — the more receptors you have, the more caffeine you need to plug them up.
One recent review of studies found that caffeine may improve heart function.
Many researchers have assumed that caffeine could potentially cause trouble for people with heart problems like arrhythmias (irregular heart beats).
But a recent review of research found this didn't seem to be the case. Looking at a number of studies with more than 330,000 participants, researchers found that irregular heartbeat frequency decreased between 6 and 13% in regular coffee drinkers. That same review found that people who'd had a heart attack who consumed caffeine (an average of 353 mg per day, or a little over 3 cups of coffee) actually had an improved heart rate and fewer irregular heartbeat issues.
The researchers think that by blocking adenosine, caffeine may reduce heart risks, since adenosine triggers irregular heartbeats.
It boosts our mood.
As a central nervous system stimulant, caffeine doesn’t just boost alertness, it can also improve your mood.
This is due to the same adenosine-blocking effect that makes you feel alert. By blocking adenosine’s relaxing effects, caffeine lets dopamine and glutamine (other natural stimulants produced by your brain) run wild, making you more alert, less bored, and providing a mood boost.
