When Napping & Caffeine Make Sense

Chronic insomniacs will have heard these messages before: “Don’t nap.” “Avoid caffeinated beverages later in the day.” These are good rules of thumb for most people with insomnia. If you catch yourself drifting off during the 6 o’clock news, it’s better to get up and walk around the block than drink coffee or indulge in a full-blown nap.

But some situations warrant breaking the rules.

sleep deprived insomniacs who must drive should have a nap & caffeineChronic insomniacs will have heard these messages before: “Don’t nap.” “Avoid caffeinated beverages later in the day.” These are good rules of thumb for most people with insomnia. If you catch yourself drifting off during the 6 o’clock news, it’s better to get up and walk around the block than drink coffee or indulge in a full-blown nap.

But some situations warrant breaking the rules. Say you end up pulling an all-nighter to study for a test and have to take a second test later the same day. Or say a family crisis triggers a couple bad nights and the next night you have to drive all the way to St. Paul. If you’ve got to be on your toes despite feeling seriously sleep deprived, then napping and well-timed use of caffeine make sense. Here’s what the research says.

Turning Low Energy into High

It’s normal to feel low energy when you’re short on sleep, and nerve-wracking when the situation calls instead for stamina and alertness. Your first impulse may be to reach for an energy drink. Energy drinks usually deliver what they promise: studies show that caffeine—a main ingredient—can improve attention, reaction speed, information processing, memory, mood, and aerobic performance.

Caffeine quickly moves from your gastrointestinal tract into your bloodstream. It’s at peak strength about 1 hour after you drink it. Caffeine blocks secretion of adenosine, in turn increasing the release of neurotransmitters that promote arousal. Fatigue falls away and your brain comes alive again.

When Caffeine Isn’t Enough

But under conditions of extreme sleep deprivation, caffeine by itself doesn’t work very well. Researchers at the University of Pennsylvania confirmed this and found out more when they conducted a double-blind study on sleep-deprived subjects to compare the effects of caffeine with and without periodic naps.

The participants, 58 healthy men (average age 29), underwent 3 nights of total sleep deprivation. Starting at hour 22, half of the men took a low-dose caffeine pill every hour on the hour, and the other half took a placebo. Half of the caffeine takers were also allowed to take a 2-hour nap every 12 hours and the other half were not. Likewise for the placebo takers.

The participants were tested repeatedly, and here’s what the investigators saw in the group taking only low-dose caffeine:

  • Compared with placebo, the caffeine significantly reduced declines in reaction time and lapses in attention associated with sleep loss, but this effect fell off as participants grew more and more sleep deprived.
  • Compared with placebo, caffeine did nothing to increase the amount of information the sleep-deprived participants could process or improve their working memory.

Adding Naps to Reduce Fatigue & Improve Performance

But taking low-dose caffeine and a 2-hour nap every 12 hours improved participants’ attention, ability to process information, and working memory. These effects held steady through all 3 days of the study. Adding caffeine to the naps also reduced the drowsiness participants felt on awakening from their naps.

The Penn researchers point out that “caffeine at any dose is not a chemical substitute for adequate healthy sleep.” But in situations where people must perform under conditions of sleep deprivation, “brief naps in combination with properly-dosed and well-timed energy products containing caffeine may provide the most benefit.”

Some people with insomnia don’t have an easy time napping, and I’m one of them. But when I’m truly suffering sleep loss—say, when I have jet lag on returning home from a trip—and I have to be up and alert, I turn on the coffee maker, nap if I can, and drink my coffee immediately on waking up.

But Note These Caveats

The effects of caffeine vary greatly from person to person largely due to genetic factors:

  • In this experiment, for example, the peak concentration of caffeine in the blood plasma of participants ranged from 2.0–9.4 mg/l. That’s a very wide range. It suggests that some participants’ behavior was much more impacted by caffeine than others’.
  • Also, some people metabolize caffeine more slowly than others. On average, caffeine has a half-life of 5–6 hours. But its half-life ranges from 2.5–10 hours (and the range is even wider in people who are pregnant, taking antidepressants, or have liver disease). A particular genetic polymorphism causes more women to metabolize caffeine more slowly than men, and more Asians and Africans to metabolize caffeine more slowly than Caucasians.

Is Short Sleep an Inborn Trait?

We’re often warned about getting less than 7 to 8 hours of sleep a night. Short sleepers—variously defined as people who sleep 5 hours and less or less than 6—are more susceptible than normal sleepers to a host of problems: cardiovascular disease, obesity, diabetes, cancer, and dementia. Many people with insomnia fall within that 5- to 6-hour range. Rarely do we get encouraging news about our prospects for a healthy life.

But recent research on genetic mutations tells a different story. Not only does it begin to explain some of the differences in sleep duration among human beings. It also suggests that short sleep may not necessarily have adverse effects on our health and quality of life.

Sleep differences in fraternal twins may occur due to different DNA sequencingWe’re often warned about getting less than 7 to 8 hours of sleep a night. Short sleepers—variously defined as people who sleep 5 hours and less or less than 6—are more susceptible than normal sleepers to a host of problems: cardiovascular disease, obesity, diabetes, cancer, and dementia. Many people with insomnia get just 5 or 6 hours of sleep a night. Rarely do we get encouraging news about our prospects for a healthy life.

But recent research on genetic mutations tells a different story. Not only does it begin to explain some of the differences in sleep duration among human beings. It also suggests that short sleep may not necessarily have adverse effects on our health and quality of life.

Short Sleep but Not Insomnia

One of these studies was published in the journal Science in 2009. In it, investigators were looking at the DNA sequences of people who naturally tended to wake up early. They located a genetic mutation in a mother and daughter who typically slept 6 to 6½ hours a night.

The women’s nights were consistently shorter than the nights of other members of their family, who did not have the mutation and who slept about 8 hours. Yet they woke up feeling well rested in the morning, with no sign of insomnia at night or fatigue during the day.

The mutation occurred in a protein (known as BHLHE41) in which one amino acid was substituted for another. This genetic variant did not interact in the usual way with nearby genes controlling circadian rhythms. So the expectation might be that this variant would have some effect on the timing of sleep, and it did. The mother and daughter were early awakeners. But it also affected the duration of their sleep, predisposing them to shorter sleep.

More Genetic Variants

Then in August 2014 another team of researchers, examining the DNA sequencing in twins and unrelated subjects, announced the discovery of 2 new genetic variants of the same protein, BHLHE41. These researchers were looking for genetic factors in humans that confer resistance to sleep loss. One of the 2 variants they identified had a big impact on both sleep and performance after sleep deprivation.

The carrier of the novel variant was a 27-year-old man whose fraternal twin, also male, did not have the mutation. The sleep-related differences between the twins were fascinating:

  1. The carrier twin slept an average of 5 hours a night—over an hour less than his brother.
  2. Despite his shorter nights, the carrier had a similar amount of nonrapid eye movement sleep (NREM sleep) as his twin. NREM sleep is composed of light sleep and deep sleep, which is associated with restorative processes.
  3. After going 38 hours without any sleep at all, the carrier twin slept 8 hours while his brother slept 9½. Yet an analysis of brainwaves showed that the carrier had higher delta power during NREM sleep, suggesting greater sleep drive.

Response to Sleep Deprivation

The brothers’ response to sleep loss was fascinating, too. After a full night without sleep, they underwent standardized testing every 2 hours to measure their cognitive vulnerability to sleep deprivation.

It wasn’t the more normal sleeper who fared better on the tests. It was the short sleeper—the carrier of the mutation—who had “significantly fewer average lapses of performance” on the tests. Based on these results and results of other studies, the researchers conclude that this novel variant of the BHLHE41 is associated both with short sleep and resistance to the effects of sleep loss.

Whether it also protects people from the health problems linked to short sleep remains to be seen. But regarding obesity, the study is reassuring. The body mass index (BMI) of the noncarrier twin was on the heavy side of “healthy,” but the carrier’s BMI was well within the healthy range.

We hear a lot about the problems associated with short sleep. But occasionally some bit of research comes along showing that our prospects for healthy lives may not be so bad after all.

Sleep Deprivation: Hurtful to Some, Manageable for Others

When you lose out on sleep—due to insomnia or for any other reason—it can handicap your performance the next day, as some Olympic athletes will attest.

But while some people are seriously compromised by sleep loss, others are remarkably resilient. Just as we humans differ in our ability to get to sleep and stay asleep at night, so we function differently after sleep deprivation.

Olympic athletes know sleep is important to doing your bestWhat does it take to medal in the Olympics? A good night’s sleep may not be the first thing that comes to mind. Yet Olympic athletes know it’s an ingredient in success.

Take US figure skater Jeremy Abbott, who admitted to thrashing a lot during his sleep. He slept poorly at the Vancouver Winter Olympics four years ago because he was worried about falling off a twin bed. This year, he took a queen-sized mattress to Sochi so he could sleep better.

Speed skater Lee Seung-hoon of Korea, on the other hand, was unlucky in sleep this time around. Lee won a silver medal in the men’s 5,000 meter in Vancouver but placed 12th in the event this year, attributing his disappointing finish to insomnia.

Different Responses to Sleep Loss

When you lose out on sleep—due to insomnia or for any other reason—it can handicap your performance the next day. But while some people are seriously compromised by sleep loss, others are remarkably resilient. Just as we humans differ in our ability to get to sleep and stay asleep at night, so we function differently after sleep deprivation, say Namni Goel and David Dinges. These researchers have identified some common genetic variants that play a role in determining who falls apart after pulling an all-nighter and who emerges unfazed.

Their research came about because of concerns voiced by scientists at NASA. Astronauts are susceptible sleep loss while traveling in space. Some are able to function and perform critical operational tasks just as well after a poor night’s sleep as after a good one. Other astronauts cannot function quickly or well when sleep deprived.

So Goel and Dinges embarked on a series of experiments. The healthy subjects of their research underwent first one night of total sleep deprivation followed by neurobehavioral testing, and, after recovering, a second night of sleep deprivation and testing. Some underwent a third night of sleep deprivation and testing. The subjects fell into three groups based on their performance of tasks involving mental and physical coordination:

1)    Those who consistently showed performance deficits when sleep deprived

2)    Those who showed amazing resistance to sleep loss

3)    Those whose performance fell somewhere in between.

All in the Genes

Goel and Dinges concluded that the way humans respond to sleep loss appears to be a stable trait. They then set about finding genetic markers that predicted their subjects’ response to sleep restriction. They identified five genes involved in sleep-wake, circadian, and cognitive regulation, whose common variations appear to protect some people from the negative effects of sleep loss and leave others in the lurch.

Moral of the story? We all need our sleep. But apparently some of us need it more than others if we’re to function at our best.

How does a bad night’s sleep affect you the next day? If you’ve noticed any impairments—physical, emotional, mental—what are they?

Sleep Deprivation and Anxiety: New Findings

Researchers at UC Berkeley have shown that sleep deprivation amplifies anxiety in people prone to worry. In a study written up in Science Daily, the researchers found that a single sleepless night greatly ramped up neural activity in two brain regions associated with the processing of emotion.

Stress and negative emotion felt strongly after sleep deprivationIt’s a vicious circle, as many people with chronic insomnia will attest. Stress and worry lead to bad nights, and the resulting sleep loss seems to magnify the worries, which in turn leads to worse nights and soaring anxiety, and on and on. Once the cycle is set in motion, it can feel impossible to stop.

Researchers at UC Berkeley have shown that sleep deprivation amplifies anxiety in people prone to worry. In a study written up in Science Daily, the researchers found that a single sleepless night greatly ramped up neural activity in two brain regions associated with the processing of emotion: the amygdala and the insular cortex. Excess activity in these two regions is common in people that have generalized anxiety disorder, panic attacks, and PTSD.

Study Particulars

Eighteen healthy young adults were the subjects in this experiment. They spent two nights in UC Berkeley’s Sleep and Neuroimaging Laboratory. They got a good night’s sleep on the first night. The second night, they stayed awake.

After both nights, they watched a slide show containing neutral and highly disturbing images, during which time their brains were scanned using functional MRI. Before each image, a visual cue was presented to create anticipation for the image that would follow. A yellow circle indicated that a neutral image such as a bicycle was going to appear. A red minus sign portended a disturbing image such as the body of a burn victim. And a white question mark signaled that either a neutral or a shocking image would flash upon the screen.

An Emotional Roller Coaster

The red minus sign and the white question mark triggered enormous anticipatory anxiety in the subjects when they were sleep deprived, as shown by the excessive neural activity occurring in the emotion centers of their brains. And in sleep-deprived subjects who were naturally prone to anxiety, the activity in the amygdala and insular cortex was sky high.

The subjects in this experiment were not insomnia sufferers. But if sleep deprivation magnifies anxiety in healthy, normal sleepers, it’s bound to boost anxiety in us. I for one am as familiar with this pattern as with the back of my hand. Bad nights heighten whatever anxiety I may be feeling, in turn begetting more bad nights and even greater anxiety.

No wonder insomniacs sometimes feel like we’re on an emotional roller coaster and powerless to make it stop.

How does insomnia affect you emotionally?

Who Says Sleep Declines with Age?

Older adults tend to sleep less than younger adults, with total sleep time declining by about 10 minutes per decade.

But the assumption that sleep problems generally increase with age does not always hold true, according to two studies recently published in the journal Sleep.

sleep-agingI used to be the only insomniac among my champion sleeper peers. Now several of my friends report experiencing insomnia. I guess that’s not surprising: we’re the baby boom generation, and sleep problems tend to increase with age. Or do they?

Older adults do tend to sleep less than younger adults, with total sleep time declining by about 10 minutes per decade. But the assumption that sleep problems generally increase with age does not always hold true, according to two studies recently published in the journal Sleep.

Study Results

Investigators in the first study analyzed complaints of sleep disturbance and tiredness in over 150,000 Americans age 18 and above. What they found was surprising:

  • The youngest group (18- to 24-year-olds) had the highest rate of reported sleep disturbance, and the oldest group (70- to 74-year-old males, and females age 80 and above) had the lowest rate.
  • The 18- to 24-year-olds and adults age 70 and older reported the highest rates of tiredness, while adults age 65 to 69 reporting the lowest rate of tiredness.
  • Overall, the investigators concluded, “both sleep disturbance and tiredness complaints generally declined across the life span.”

In the second study, researchers took data from over 84,000 people in England and Finland and looked to see how sleep lost over worry changed with age. These findings, too, suggest that sleep quality doesn’t necessarily decline with age:

  • Sleep loss over worry was highest among 34- to 55-year-olds.
  • There was a decline in sleep loss over worry between the ages of 56 and 65 (in women, however, the decline began somewhat later than in men).
  • Sleep loss over worry was the lowest in old age.

Sleep Complaints, Health, and Stress

How can we explain why people in the oldest age groups reported better quality sleep than younger people? One factor that may be involved is overall health. People develop more health problems as they age, and many of these problems have a negative impact on sleep and on mortality. People who survive into the oldest age groups may be particularly resilient to age-related health problems and thus may not experience the associated problems with sleep.

Stress is clearly a factor in the sleep loss over worry reported by the younger groups: people in their 20s and 30s are completing college degrees, entering the job market, and bearing and rearing children. Baby boomers well along in middle age are contending with a few stressors too: we’re developing health problems; losing jobs to a younger, cheaper workforce; caring for sick parents; and even parenting grandchildren. Maybe it’s only the luckiest among us that will slide into old age with a clean bill of health and sound, restorative sleep.

Anyway, when I talk about insomnia these days, I’m not the Lonely Hearts Club Band member I used to be. Now I’ve got plenty of company.

If you’ve got a sleep problem, when did it begin? Was it related to stress or something else?

Age and Sleep Disturbances

Sleep Lost over Worry