Recent quotes:

Starving for light – henry copeland – Medium

Without seeing a 30 minute dose of bright light each morning, your circadian clock can derail, affecting everything from gene expression to hormonal ebbs and flows to testosterone levels to virus virility to brain waves to immunity to REM patterns to fertility to heart rates to hunger to cancer.

Color-Changing LEDs Could Reset the Circadian Rhythm - The Atlantic

Hints of positive impacts have emerged in Texas, too, where tunable LED systems have been installed in some elementary and middle-school classrooms in Carrollton, a northern suburb of Dallas. A September DOE report on the Carrollton systems suggested that the tunable LED system had improved the overall learning environment—though the DOE noted that empirically measuring the effects of the circadian lights was beyond the scope of the project. Back in Washington, entire schools—including two Renton high schools and a brand new middle school—now have circadian lighting, and initial data out of Lindbergh High School seemed to echo the findings in Texas: The school reported a double-digit rise in SAT test scores following installation of the tunable LEDs.

Color-Changing LEDs Could Reset the Circadian Rhythm - The Atlantic

In much the same way as the ear allows us to both hear and stay balanced, the eye’s rods and cones supply us with vision while these novel intrinsic photosensitive retinal ganglion cells, or ipRGCs, perform a separate function: They sense the quality and quantity of light, with input from the rods and cones, and send that information to a master circadian clock in the brain. That clock then conducts a symphony of cellular timepieces throughout the body, ensuring they all “rise and fall with appropriate relationships to the others,” explains Berson.

Evening use of light-emitting tablets may disrupt healthy sleep -- ScienceDaily

On evenings when using light-emitting tablets, participants' self-selected bedtimes were on average half an hour later, and they showed suppressed melatonin levels, delayed timing of melatonin secretion onset, and later sleep onset. When using the tablets, participants rated themselves as less sleepy in the evenings and less alert in the first hour after awakening on the following mornings.

Geographic variation in the prevalence of attention-deficit/hyperactivity disorder: the sunny perspective. - PubMed - NCBI

The preventative effect of high SI might be related to an improvement of circadian clock disturbances, which have recently been associated with ADHD. These findings likely apply to a substantial subgroup of ADHD patients and have major implications in our understanding of the etiology and possibly prevention of ADHD by medical professionals, schools, parents, and manufacturers of mobile devices.

Morning sun 99.9% correlates with improved sleep

The Pittsburgh Sleep Quality Index, the Demographic Data Form, and the Follow-up Form for Elderly were used for data collection, whereas the Pittsburgh Sleep Quality Index was used for sample selection. It was found that exposure to direct sunlight between 8 AM and 10 AM for 5 days seems to be effective in increasing the global sleep quality score (P < .001).

Study links night exposure to blue light with breast and prostate cancer: Researchers used images taken by astronauts to evaluate outdoor lighting in Madrid and Barcelona -- ScienceDaily

Results obtained for both cities show that participants exposed to higher levels of blue light had a 1.5 and 2-fold higher risk of developing breast and prostate cancer, respectively, as compared to the less-exposed population.

Effects of night-time light on internal body clock -- ScienceDaily

Melatonin suppression and circadian phase resetting are often correlated such that high levels of melatonin suppression can be associated with large shifts of the body clock. This association between the two responses has often been assumed to represent a functional relationship, resulting in the acceptance that one could be used as a proxy measure for the other. Circadian phase resetting is more difficult to measure than melatonin suppression, meaning the latter has often been used to assess disruption to the body clock caused by light exposure at night. However, this research has found that the magnitude of the shift in internal body clock is functionally independent from melatonin suppression. This casts doubt on the use of melatonin suppression as a proxy for circadian phase resetting. This knowledge may shape future research designed to improve treatments for depression and shift work sleep disorder.

Brain activity linked to stress changes chemical codes: Findings may be relevant to other disorders, from autism to PTSD -- ScienceDaily

In the new findings, the researchers studied the change in neurotransmitter identity when rats, which are nocturnal, are exposed to long day lengths. This exposure led to elevated activity of paraventricular (PaVN) neurons in the hypothalamus and by consequence a loss in their expression of dopamine, a neurotransmitter that is linked with many aspects of normal behavior. When the researchers suppressed the elevation of activity that resulted from the long-day exposure, exclusively in the PaVN neurons, they blocked the transmitter switch that would have occurred under these normal light conditions.

Sunlight May Be the Next Beet Juice | Outside Online

The study involved shining two different doses of ultraviolet light (specifically UVA light—wavelengths between 315 and 400 nanometers) on ten volunteers, then measuring its effects on a range of outcomes like blood pressure, resting metabolism, and nitrite and nitrate levels. It’s this last bit that caught my attention, because the rise of beet juice as an endurance-boosting supplement is due to its high levels of nitrate. The body converts that nitrate to nitrite and then to nitric oxide, which seems to make your muscles work more efficiently during endurance exercise. These studies have also found that boosting levels of nitric oxide has other health benefits, like acutely lowering blood pressure and regulating blood sugar. (In fact, one recent study found that using mouthwash twice a day or more, which wipes out the oral bacteria that convert nitrate to nitrite, was associated with a 50 percent increase in the risk of developing prediabetes or diabetes.)

Living in a sunnier climate as a child and young adult may reduce risk of MS: Getting more summer sun also associated with lower risk -- ScienceDaily

They found that women who lived in sunnier climates with the highest exposure to UV-B rays had 45 percent reduced risk of developing MS across all pre-MS onset age groups when compared to those living in areas with the lowest UV-B ray exposure. When looking at specific age groups, those who lived in areas with the highest levels of UV-B rays between ages 5 to 15 had a 51 percent reduced risk of MS compared to the lowest group. A total of 33 of 147 people with MS, or 22 percent, had high exposure at ages 5 to 15, while 61 people, or 41 percent, had low exposure. In addition, those who spent more time outdoors in the summer at ages 5 to 15 in locations where exposure to UV-B rays was the highest had a 55 percent reduced risk of developing the disease compared to those in the lowest-exposure group.

Our circadian clock sets the rhythm for our cells’ powerhouses -- ScienceDaily

Countless genetically controlled clocks tick inside different parts of our bodies, such as the liver, kidneys and heart. Among other things, they initiate many metabolic processes, ensuring that these occur at the optimal time of day. Mitochondria -- small organelles that exist in almost all our cells and supply them with energy -- play an important role in these cellular processes. Until now, it was unclear how exactly the 24-hour circadian rhythm regulated energy metabolism. Fission protein sets the rhythm In most cells, mitochondria connect in a constantly changing network that can adapt to various conditions. Mitochondria can thus fuse together and then divide again. Disruption of this fission-fusion dynamic can lead to health problems. Researchers have now investigated exactly how the mitochondrial network interacts with our internal biological clock by using a combination of in vitro models and clock-deficient mice or mice with impaired mitochondrial fission. Their results show that the mitochondrial fission-fusion cycle is controlled by the fission protein Drp1, which is in turn synchronized by an internal biological clock. This rhythm is integral to determining when and how much energy the mitochondria can supply. "The time of day determines the design of the mitochondrial network, and this, in turn, influences the cells' energy capacity," explains study leader Professor Anne Eckert from the University of Basel's Transfaculty Research Platform Molecular and Cognitive Neurosciences MCN.

Recap of sunlight with links

Although medical curiosity about the salubrious benefits of sunlight exposure can be traced to antiquity [1,2], contemporary clinical interest was ignited by the 20th-century discovery of a direct link between light exposure and circadian melatonin production [3,4]. An obvious initial candidate for bright light therapy (LT) was seasonal affective disorder [5] – a form of depressive illness typically triggered by light deprivation during the short, cold days of winter – and the intervention has proven to be efficacious across a large number of randomized controlled trials [6-8]. In fact, the efficacy of LT has now been supported across a range of other mood disorders, including non-seasonal depression [9,10,6], bipolar disorder [11,12], antepartum and postpartum depression [13,14], and premenstrual dysphoric disorder [15,16]. Light therapy (LT) has also been successfully applied to the treatment of sleep disorders [17-20], as well as circadian phase sleep disorders associated with jet lag [21,22] and shift work [23,24]. More recently, LT has shown promise as an intervention for obsessive-compulsive symptoms [25], behavioral disturbances and functioning in dementia and Alzheimer’s disease [26,27], primary and secondary features of Parkinson’s disease [28], attention deficit hyperactivity disorder [29], seasonal variations in eating disturbances associated with bulimia nervosa [30,31], and some symptoms of chronic anorexia [32].

Visualizing assemblies of the proteins that direct cyanobacterial circadian rhythms

KaiB, though, flips between two different shapes, and is only active when it's in an unstable shape—a situation that until now made crystallization impossible. "We mutated KaiB so that it stayed in its active shape, and when we added KaiA and KaiC they arranged themselves around it as they do at night," LiWang said. "We found the secret sauce that allows us to figure out how the springs and gears go together." They were amazed that they obtained crystals within a day of combining the proteins. They also solved an NMR structure of a complex between the active form of KaiB and the domain of a protein (CikA) that transmits signals to regulate gene expression in cyanobacteria. "It's really remarkable that the cyanobacterial clock is so dependent on this rare state of KaiB," Partch said. "The mechanistic information we're getting out of these structures is allowing us to piece together how the clock manages to keep 24-hour time. We're now looking for similar clues in other circadian timekeeping systems, including our own."

Clock protein controls daily cycle of gene expression by regulating chromosome loops: New understanding of Rev-erb's role has implications for metabolic disorders, cardiovascular disease, and cancer -- ScienceDaily

Human physiology works on a 24-hour cycle of gene expression (when the chromosome coding region is translated by RNA and then transcribed to make protein) and is controlled by the body's molecular clock. Core clock proteins activate or repress protein complexes that physically loop one part of a chromosome to become adjacent to a distant part of the same chromosome. The Penn team showed that daily oscillations of Rev-erb control gene expression in the mouse liver via interactions between on-and-off regions on the same chromosome. Previous work from the team demonstrated that by 5 p.m., Rev-erb increases to its highest concentration in mouse liver, where it turns off certain genes and therefore protein transcription. But as the day turns to night, its concentration steadily decreases and nearly vanishes from the liver by 5 a.m.

Does dim light make us dumber? -- ScienceDaily

Spending too much time in dimly lit rooms and offices may actually change the brain's structure and hurt one's ability to remember and learn, indicates groundbreaking research by Michigan State University neuroscientists. The researchers studied the brains of Nile grass rats (which, like humans, are diurnal and sleep at night) after exposing them to dim and bright light for four weeks. The rodents exposed to dim light lost about 30 percent of capacity in the hippocampus, a critical brain region for learning and memory, and performed poorly on a spatial task they had trained on previously. The rats exposed to bright light, on the other hand, showed significant improvement on the spatial task. Further, when the rodents that had been exposed to dim light were then exposed to bright light for four weeks (after a month-long break), their brain capacity -- and performance on the task -- recovered fully.

UV Sense

I’ll make a bold claim: one hundred years from now, the UV Sense and its peers may be celebrated for being as important to health in the 21st century as insulin and penicillin were in the 20th century. UV Sense is one of a whole new class of consumer-targetted devices/services like FitBit, Spire, 23andme, home-built EEGs, and various microbiome sensors and assays that are as powerful as could be found a decade ago in cutting-edge research labs. Combined with crowdsourcing and cheap big data tools, these people-empowering devices will help individuals pursue hypotheses that no profit-driven business cares (or dares) to examine.

Amber-tinted glasses may provide relief for insomnia -- ScienceDaily

To test their theory, the researchers recruited 14 individuals with an insomnia diagnosis to take part in a small study. For seven consecutive nights, participants wore wrap-around frames with amber-tinted lenses that blocked blue light or with clear placebo lenses for two hours before bedtime. Four weeks later, participants repeated the protocol with the other set of glasses. The researchers found that participants got around 30 minutes extra sleep when they wore the amber lenses compared to the clear lenses. In self-reported sleep surveys, participants also reported greater duration, quality, and soundness of sleep, and an overall reduction in insomnia severity.

Time matters: Does our biological clock keep cancer at bay? -- ScienceDaily

Relógio, whose surname in Portuguese means "clock," says: "Based on our results, it seems to us that the clock is likely to act as a tumour suppressor, and that it is of advantage for cancer cells to circumvent circadian control. One cannot stop wondering whether disrupted circadian timing should be included as a next potential hallmark of cancer."

Outdoor light at night linked with increased breast cancer risk in women | News | Harvard T.H. Chan School of Public Health

Women exposed to the highest levels of outdoor light at night—those in the top fifth—had an estimated 14% increased risk of breast cancer during the study period, as compared with women in the bottom fifth of exposure, the researchers found. As levels of outdoor light at night increased, so did breast cancer rates.

New Yorker Menuchin on the eclipse: meh.

"You know, people in Kentucky took this stuff very serious," he told the conference. "Being a New Yorker and (living for a time in) California, I was like, the eclipse? Really? I don't have any interest in watching the eclipse."

Comparisons of three practical field devices used to measure personal light exposures and activity levelsLighting Research &amp; Technology - MG Figueiro, R Hamner, A Bierman, MS Rea, 2013

This paper documents the spectral and spatial performance characteristics of two new versions of the Daysimeter, devices developed and calibrated by the Lighting Research Center to measure and record personal circadian light exposure and activity levels, and compares them to those of the Actiwatch Spectrum. Photometric errors from the Daysimeters and the Actiwatch Spectrum were also determined for various types of light sources. The Daysimeters had better photometric performance than the Actiwatch Spectrum. To assess differences associated with measuring light and activity levels at different locations on the body, older adults wore four Daysimeters and an Actiwatch Spectrum for seven consecutive days. Wearing the Daysimeter or Actiwatch Spectrum on the wrist compromises accurate light measurements relative to locating a calibrated photosensor at the plane of the cornea.

Effects of exercise with or without light exposure on sleep quality and hormone reponses

Cycling adenosine monophosphate (cAMP) gets released by the stimulus of adrenocortical hormones due to intake of coffee, tea, chocolate, or stress. Excessive cAMP release accelerates energy release to reach excitement condition that leads us to be nervous and unsettled. However, sunlight exposure decreases cAMP, leading to peaceful and settled conditions [53].

10x risk of death from non-skin cancer due to low sun exposure

Many studies have shown that cancer-related death rates decline as one moves toward the lower latitudes (between 37°N and 37°S), and that the levels of ambient UVR in different municipalities correlate inversely with cancer death rates there. “As you head from north to south, you may find perhaps two or three extra deaths [per hundred thousand people] from skin cancer,” says Vieth. “At the same time, though, you’ll find thirty or forty fewer deaths for the other major cancers. So when you estimate the number of deaths likely to be attributable to UV light or vitamin D, it does is not appear to be the best policy to advise people to simply keep out of the sun just to prevent skin cancer.”

Lower risk of high blood pressure with sunlight

exposed a group of hypertensive adults to a tanning bed that emitted full-spectrum UVR similar to summer sunlight. Another group of hypertensive adults was exposed to a tanning bed that emitted UVA-only radiation similar to winter sunlight. After three months, those who used the full-spectrum tanning bed had an average 180% increase in their 25(OH)D levels and an average 6 mm Hg decrease in their systolic and diastolic blood pressures, bringing them into the normal range. In constrast, the group that used the UVA-only tanning bed showed no change in either 25(OH)D or blood pressure.

Low vitamin D = 4-5X increase in risk of type 1 diabetes

A Swedish epidemiologic study published in the December 2006 issue of Diabetologia found that sufficient vitamin D status in early life was associated with a lower risk of developing type 1 diabetes. Nonobese mice of a strain predisposed to develop type 1 diabetes showed an 80% reduced risk of developing the disease when they received a daily dietary dose of 1,25(OH)D, according to research published in the June 1994 issue of the same journal. And a Finnish study published 3 November 2001 in The Lancet showed that children who received 2,000 IU vitamin D per day from 1 year of age on had an 80% decreased risk of developing type 1 diabetes later in life, whereas children who were vitamin D deficient had a fourfold increased risk. Researchers are now seeking to understand how much UVR/vitamin D is needed to lower the risk of diabetes and whether this is a factor only in high-risk groups.