Why The Circadian Rhythm Affects Health
Overview of biological circadian clock in humans. Biological clock affects the daily rhythm of many physiological processes. This diagram depicts the circadian patterns typical of someone who rises early in morning, eats lunch around noon, and sleeps at night (10 p.m.). Although circadian rhythms tend to be synchronized with cycles of light and dark, other factors – such as ambient temperature, meal times, napping schedule and duration, stress and exercise – can influence the timing as well. (Photo credit: Wikipedia)
From the 30 August 2012 article at Medical News Today
Disruptions to the circadian rhythm can affect the growth of blood vessels in the body, thus causing illnesses such asdiabetes, obesity, and cancer, according to a new study from Linkoping University and Karolinska Institutet.
The circadian rhythm is regulated by a “clock” that reacts to both incoming light and genetic factors.
In an article now being published in the scientific journal Cell Reports, it is demonstrated for the first time that disruption of the circadian rhythm immediately inhibits blood vessel growth in zebra fish embryos.
Professor Yihai Cao leads a research group, which has demonstrated that the breaking point is the production of a very important signalling substance: vascular endothelial growth factor (VEGF). The formation of this substance requires a normal circadian rhythm…
..
“The results can definitely be translated into clinical circumstances. Individuals with disrupted circadian rhythms – for example, shift workers who work under artificial lights at night, people with sleep disorders or a genetic predisposition – should be on guard against illnesses associated with disrupted blood vessel growth,” says Lasse Dahl Jensen (pictured), researcher in Cardiovascular Physiology at Linköping University (LiU), and lead writer of the article.
Such diseases include heart attack, stroke, chronic inflammation, and cancer. Disruptions in blood vessel growth can also affect foetal development, women’s reproductive cycles, and the healing of wounds.
Related articles
- Living Against the Clock: Does Loss of Daily Rhythms Cause Obesity? (sott.net)
- Living against the clock: Does loss of daily rhythms cause obesity? (eurekalert.org)
- iPads, Tablets Can Wreak Havoc on Sleep Patterns (atlantablackstar.com)
- The Four Pillars of Getting Sleep (theepochtimes.com)
- Artificial light and obesity epidemic: Is there a link? (junkscience.com)
- Molecular Link Between Circadian Clock Disturbances And Inflammatory Diseases (prn.fm)
- The Circadian Advantage: How Sleep Patterns Benefit Certain NFL Teams [Sleep] (deadspin.com)
- Get in touch with your inner rhythm (mariahsbutterflyz.wordpress.com)
- Experts Believe Festive Break Could Cause Misaligned Circadian Rhythm (prweb.com)
Another reason to get your Z’s- prevent a nursing home admission

English: Banks o’Dee Nursing Home Modern Care Home for the elderly in Abbotswell Road, Aberdeen. (Photo credit: Wikipedia)
From the 19th July 2012 article at ScienceNewsDaily
Tired? Scientists have discovered another possible benefit of a night of restful and uninterrupted sleep. According to a new study led by researchers at the Johns Hopkins Bloomberg School of Public Health fragmented or interrupted sleep could predict future placement in a nursing home or assisted living facility. The study is featured in the July 2012 issue of the Journal of the American Geriatrics Society and outlines the association between objectively measured sleep and subsequent institutionalization among older women.
“Sleep disturbances are common in older people,” said Adam Spira, PhD, lead author of the study and an assistant professor with the Bloomberg School’s Department of Mental Health. “Our results show that in community-dwelling older women, more fragmented sleep is associated with a greater risk of being placed in a nursing home or in a personal care home. We found that, compared to women with the least fragmented sleep, those who spent the most time awake after first falling asleep had about 3 times the odds of placement in a nursing home. Individuals with the lowest sleep efficiency — those who spent the smallest proportion of their time in bed actually sleeping — also had about 3 times the odds of nursing home placement.” The authors found similar patterns of associations between disturbed sleep and placement in personal care homes, such as assisted-living facilities. Sleep duration per se did not predict placement in either of these settings…
Is napping good for you? – Ask Doctor K, Harvard Medical School
Is napping good for you? – Ask Doctor K, Harvard Medical School.
Excerpts from the article
POSTED NOVEMBER 24, 2011, 5:00 AM DEAR DOCTOR K:
As I’ve gotten older I don’t sleep as well as I used to. I’m retired, so I have the time to take an afternoon nap. But I’m worried that if I sleep during the day, I’ll have even more trouble sleeping at night. What do you think?
DEAR READER:
I’m not surprised that you don’t sleep as well as you used to. Our sleep changes as we get older.
After about age 60, we have less deep sleep. We awaken more often and sleep an average of two hours less at night than we did as young adults.
It was once thought that older people didn’t need as much sleep as younger ones. But that’s not the case; we need it just as much. We just have a harder time getting it.
Regardless of age, we typically need seven and a half to eight hours of sleep to function at our best. So if you’re not getting enough sleep at night, what about daytime naps? Or, as you asked, does napping disrupt the sleep cycle? Will napping ultimately lead to less sleep and more daytime drowsiness?
Everybody’s different, and napping is both good and bad, depending on who you are. If you have trouble sleeping nearly every night, and as a result feel tired during the day, napping in the evening is a bad idea. Evening naps make it harder to fall asleep at bedtime. Long naps at any time of day often make you sleep less soundly that night.
On the other hand, suppose you have an occasional bad night’s sleep….
Related articles
- The Secret and Surprising Power of Naps (webmd.com)
- Do power naps work? (zocdoc.com)
- Mastering the Art of Sleep (enfamil.com)
- 18 and Under: A Child’s Nap Is More Complicated Than It Looks (nytimes.com)
Physical activity impacts overall quality of sleep
Physical activity impacts overall quality of sleep
From the Eureka News Alert item of Tue Nov 22, 2011 13:48
(Oregon State University) People sleep significantly better and feel more alert during the day if they get at least 150 minutes of exercise a week, a new study concludes.
A nationally representative sample of more than 2,600 men and women, ages 18-85, found that 150 minutes of moderate to vigorous activity a week, which is the national guideline, provided a 65 percent improvement in sleep quality. People also said they felt less sleepy during the day, compared to those with less physical activity.
The study, out in the December issue of the journal Mental Health and Physical Activity, lends more evidence to mounting research showing the importance of exercise to a number of health factors. Among adults in the United States, about 35 to 40 percent of the population has problems with falling asleep or with daytime sleepiness.
“We were using the physical activity guidelines set forth for cardiovascular health, but it appears that those guidelines might have a spillover effect to other areas of health,” said Brad Cardinal, a professor of exercise science at Oregon State University and one of the study’s authors.
“Increasingly, the scientific evidence is encouraging as regular physical activity may serve as a non-pharmaceutical alternative to improve sleep.”
After controlling for age, BMI (Body Mass Index), health status, smoking status, and depression, the relative risk of often feeling overly sleepy during the day compared to never feeling overly sleepy during the day decreased by 65 percent for participants meeting physical activity guidelines.
Similar results were also found for having leg cramps while sleeping (68 percent less likely) and having difficulty concentrating when tired (45 percent decrease).
Paul Loprinzi, an assistant professor at Bellarmine University is lead author of the study, which was conducted while he was a doctoral student in Cardinal’s lab at OSU. He said it is the first study to examine the relationship between accelerometer-measured physical activity and sleep while utilizing a nationally representative sample of adults of all ages.
‘Our findings demonstrate a link between regular physical activity and perceptions of sleepiness during the day, which suggests that participation in physical activity on a regular basis may positively influence an individual’s productivity at work, or in the case of a student, influence their ability to pay attention in class,” he said.
Cardinal said past studies linking physical activity and sleep used only self-reports of exercise. The danger with this is that many people tend to overestimate the amount of activity they do, he said.
He added that the take-away for consumers is to remember that exercise has a number of health benefits, and that can include helping feel alert and awake.
“Physical activity may not just be good for the waistline and heart, but it also can help you sleep,” Cardinal said. “There are trade-offs. It may be easier when you are tired to skip the workout and go to sleep, but it may be beneficial for your long-term health to make the hard decision and get your exercise.”
Related articles
- Physical activity impacts overall quality of sleep (eurekalert.org)
- Teens & Sleep: How (and Why) to Help Your Teen Get Some Rest (psychologytoday.com)
- Can sleep apnoea be eased by a Mediterranean diet? (time4sleep.co.uk)
- Daily exercise, minimized computer time for optimal sleep in teens (medicalxpress.com)
- The secret to a better brain, a younger face and a longer life. (talesfromthelou.wordpress.com)
- How much exercise do I need? (bupa.com.au)
- A More Restful Night Awaits You When You Use These Three Approaches to Coping with Insomnia (bigsexymedia.com)
3 p.m. slump? Why a sugar rush may not be the answer
From the 17 November Eureka News Alert
Protein, not sugar, stimulates cells keeping us thin and awake, new study suggests
A new study has found that protein and not sugar activates the cells responsible for keeping us awake and burning calories. The research, published in the 17 November issue of the scientific journal Neuron, has implications for understanding obesity and sleep disorders.
Wakefulness and energy expenditure rely on “orexin cells”, which secrete a stimulant called orexin/hypocretin in the brain. Reduced activity in these unique cells results in narcolepsy and has been linked to weight gain.
Scientists at the University of Cambridge compared actions of different nutrients on orexin cells. They found that amino acids – nutrients found in proteins such as egg whites – stimulate orexin neurons much more than other nutrients….
…”To combat obesity and insomnia in today’s society, we need more information on how diet affects sleep and appetite cells. For now, research suggests that if you have a choice between jam on toast, or egg whites on toast, go for the latter! Even though the two may contain the same number of calories, having a bit of protein will tell the body to burn more calories out of those consumed.”
Related articles
- Weight Gain Likely In Narcoleptics (medicalnewstoday.com)
- Sleep hormone restores vigor and reverses apathy in sickness, Oregon scientists report (oregonlive.com)
- Hormone fights fat with fat: Orexin prevents obesity in mice by activating calorie-burning brown fat (sciencedaily.com)
- What makes us feel ‘bad’ when sick and how to treat it (news.bioscholar.com)
- Why You Don’t Want to Wake Up – Interrupted Sleep Interrupts Memory (pt5.psychologytoday.com)
- Is Light Keeping You Awake? (psychologytoday.com)
Scientists Identify What Makes Us Feel ‘Bad’ When We’re Sick, How to Treat It
From the 3 August 2011 Science Daily article
ScienceDaily (Aug. 3, 2011) — A signaling system in the brain previously shown to regulate sleep is also responsible for inducing lethargy during illness, according to research conducted at Oregon Health & Science University Doernbecher Children’s Hospital.
This research is particularly meaningful because it implies that a new class of drugs developed to treat sleep disorders can reverse the inactivity and exhaustion brought on by acute illness. Although the sleep drugs were initially designed to treat narcolepsy, they have the potential to restore energy and motivation in patients with acute and chronic disease, the researchers report. Their findings are published in the The Journal of Neuroscience.
“We all know what it means to feel ‘bad’ when we’re acutely ill. In particular, patients with chronic diseases experience a compromise in motivated behaviors. They don’t feel like getting up and doing anything. Yet the brain mechanisms behind this common experience have remained obscure,” said Daniel L. Marks, M.D., Ph.D., principal investigator and associate professor of pediatrics in the Papé Family Pediatric Research Institute at OHSU Doernbecher Children’s Hospital….
Related articles
- For Men and Women, Response to Stress Is Very Different (fitsugar.com)
- Too Sick to Work? (webmd.com)