Eat Carbs in the Morning, Fat at Night?

MedicalResearch.com Interview with:
"Compare-the-Use-of-Carbohydrates-and-Lipids-in-Energy-Storage" by Zappys Technology Solutions is licensed under CC BY 2.0Kirsi-Marja Zitting, Ph.D.

Instructor in Medicine, Harvard Medical School
Division of Sleep and Circadian Disorders
Departments of Medicine and Neurology
Brigham and Women’s Hospital
Boston, MA 02115

MedicalResearch.com: What is the background for this study?

Response: This study is a follow-up study to our previous study where we found that chronic insufficient sleep together with chronic jet lag is associated with adverse changes in metabolism, including increase in blood sugar levels (Buxton et al. Science Translational Medicine, 2012). The present study focuses on the influence of the time of day on metabolism, which has not been investigated in humans independent of the effects of sleep, physical activity and diet.

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Early Dinner May Lower Cancer Risk

MedicalResearch.com Interview with:
“Christmas Roast and Ham Dinner. Had Tamales for Christmas Eve and Christmas morning. #Roast #Ham #ChristmasDinner #Christmas #Champagne #Dinner #Foodstagram” by Yvonne Esperanza is licensed under CC BY 2.0Manolis Kogevinas, MD, PhD

Research Professor
NCDs & Environment Group
Barcelona Institute for Global Health (ISGlobal) – Campus MAR
Barcelona Biomedical Research Park (PRBB) (office 194)
Barcelona, Spain

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: We did the study for two main reasons.

(i) breast and to a less extent prostate cancer are the cancers that have been associated with night shift work and resulting circadian disruption (disruption of the natural day-light cycle);

(ii) experimental studies in animals indicate that timing of diet is important. For example, giving an hypercaloric diet to mice during the day results in obesity, while giving the same diet during the night does not. Mice are nocturnal animals and this means that there normal eating time is the night when they can metabolise what they eat. So, would something similar affect humans? When we eat in late hours at a time when “normally” (normally in the sense of evolution) we would be resting.

In this study we show that adherence to a more diurnal eating pattern and specifically an early supper and a long interval between last meal and sleep are associated with a lower breast and prostate cancer risk. Specifically having super before 9pm and having an interval of 2 hours between the last big meal and sleep, were both associated with an approximately 20% prevention of breast and prostate cancer) compared to those who have supper after 10pm or those who eat and then sleep very close after supper.

Also, the strongest protection was found in “morning types” as compared to “evening types”. Morning types are expected to function worse than evening types in late evening so late suppers may have more adverse effects on them.

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Digestive Organs Have Separate Biologic Clocks From Brain’s Master Clock

MedicalResearch.com Interview with:

Dr. Hans Van Dongen, PhD Director of the Sleep and Performance Research Center. ELSON S. FLOYD COLLEGE OF MEDICIN Washington State University Spokane, WA

Dr. VAN DONGEN

Dr. Hans Van Dongen, PhD
Director of the Sleep and Performance Research Center.
ELSON S. FLOYD COLLEGE OF MEDICIN
Washington State University
Spokane, WA

MedicalResearch.com: What is the background for this study?

Response: Night shift workers are at increased risk of metabolic disorders, including obesity and type 2 diabetes, as well as cardiovascular disease, chronic kidney disease, and cancer. Although it is believed that the biological clock – the master circadian clock in the brain – plays an important role in these adverse chronic health consequences of night shift work, the underlying mechanisms are not well understood. Continue reading

Disturbed Circadian Rhythm Associated With Poor Mental Health

MedicalResearch.com Interview with:

Laura Lyall  MA; MSc; PhD Research Associate Institute of Health and Wellbeing University of Glasgow

Dr. Lyall

Laura Lyall  MA; MSc; PhD
Research Associate
Institute of Health and Wellbeing
University of Glasgow 

MedicalResearch.com: What is the background for this study?  

Response: Previous studies have suggested a link between disturbed circadian rhythms and depression and bipolar disorder. These studies have however usually used small samples, subjective measures of circadian disruption, or have not accounted for potential confounding factors like sociodemographic and lifestyle characteristics. The UK Biobank cohort has accelerometry (activity monitor) data as well as mental health, lifestyle, BMI and sociodemographic data for over 91,000 individuals, and means we can address this question using objective measures of circadian rhythmicity on a large scale.

We derived a measure of relative amplitude from the UK Biobank’s accelerometry data, which was recorded for 7 days between 2013-2014 from around 100,000 participants. Relative amplitude reflects the distinction, in terms of activity levels, between an individual’s most active 10 hours and least active 5 hours, in an average day. If an individual is inactive during the day, or has disturbed sleep at night, the will show low relative amplitude, consistent with disturbed circadian rest-activity patterns.

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As We Age, Our Circadian Clock Becomes Less Sensitive To Light, Leading To Sleep Problems

MedicalResearch.com Interview with:
“Woman sleeping” by Timothy Krause is licensed under CC BY 2.0Dr Gurprit S. Lall BSc, MSc, PhD, PGCHE, FHEA

Medway School of Pharmacy
Interim Deputy Head of School
Senior Lecturer in Pharmacology
Director of Graduate Studies (Research),
University of Kent at Medway
Chatham Maritime, Chatham, Kent

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Medical advancement in prevention and diagnosis of disease has increased life expectancy significantly, thus generating an ageing population far greater than previously seen.  Because of this, it is essential that we begin to understand the ageing process, together with the health implications associated with senescence.  Recent research has found that changes in the circadian clock, located in the brain, play a contributing role in the decline of many physiological and behavioural traits observed through the ageing process.  One example of this, which is commonly seen in the elderly is a decline in sleep-wake cycle regulation; typically presenting as disrupted sleeping patterns.

The circadian clock, in mammals, possesses the ability to integrate our social lifestyle choices with the environmental day-night cycle to generate a 24-hour rhythm to which our physiological functions are synchronised.  It is this synchronisation that plays a vital role in regulating many of our behavioural outputs, such as sleeping-wake patterns.  This clock takes its strongest timing cue from the natural day night cycle governed by the duration of daily sunlight.

Our study investigated the changes in the interpretation of this light signal by the circadian clock as we age and its impact on function.  We found that the clock became less responsive to light stimuli at both the level of clock cells and at driving behavioural activity.  We were able to narrow this down to changes in the proteins within cells that relay light information to the molecular time setting machinery.  In detail, light signals are relayed to the clock through an excitatory neurotransmitter called glutamate and this signal is predominantly relayed through NMDA receptors located on the surface of clock cells.  It is the configuration of the NMDA receptor that alters as we age and this leads to the clock becoming less responsive to light.

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Matching Time of Day To Patient’s Biorhythm May Improve Surgical Outcomes

MedicalResearch.com Interview with:
Prof David Montaigne MD

Faculté de Médecine de Lille H Warembourg
Lille, France

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: It is well known for many decades that cardiovascular diseases exhibit a diurnal variation with for instance higher incidence of myocardial infarction in the early morning as opposed to the evening. Although studies on circadian gene knock-out and mutant mice argue for a biorhythm in myocardial ischemia-reperfusion tolerance, whether a biorhythm in the myocardial tolerance to ischemia, exists in humans was unclear because of conflicting reports in the context of myocardial infarction.

We demonstrated for the first time in humans that the myocardial tolerance to ischemia-reperfusion is different along the day, in line with rodent experiments performed in the early 2010s.

We demonstrated that this biorhythm is clinically meaningful and that it can be targeted as a cardioprotective strategy.

In this topic, Rever-alpha is of specific interest. It belongs at the same time to circadian genes and nuclear receptor families: being a nuclear receptor, it is a feasible pharmacological target, conversely to other circadian genes.

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Considering Circadian Rhythms May Aide in Diagnosis of Consciousness Disorders

MedicalResearch.com Interview with:

Copyright Anna-Lisa Bexten Dr. Christine Blume PhD Post-Doctoral Researcher University of Salzburg Centre for Cognitive Neuroscience (CCNS) Laboratory for Sleep, Cognition & Consciousness Research Salzburg

Dr. Christine Blume

Dr. Christine Blume PhD
Post-Doctoral Researcher
University of Salzburg
Centre for Cognitive Neuroscience (CCNS)
Laboratory for Sleep, Cognition & Consciousness Research
Salzburg

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: We are governed by rhythmic processes. Many of these processes follow a circadian pattern, that is, they have a period length of approximately 24 hours and are under tight control of a biological master clock located in the suprachiasmatic nucleus of the hypothalamus. Given the circadian variation in global states like alertness, it is not surprising that consciousness also varies rhythmically in healthy individuals, it follows the sleep-wake cycle.

From a clinical perspective, misalignment of circadian rhythms, which occurs when the sleep-wake schedule is at odds with the light-dark cycle as in the case of night shifts, can cause considerable stress, have detrimental effects on the immune system and impair cognitive abilities. Despite the knowledge that entrained circadian rhythms are important for healthy body and brain functioning, very little is known about circadian rhythms in patients diagnosed with a disorder of consciousness (DOC) following severe brain injuries. We argue that studying circadian rhythms in DOC patients may be especially interesting and important for two reasons.

First, the presence or absence of circadian rhythms as well as anomalies in them could be informative about the state of the patient as well as their potential for recovery.

Second, this could provide information about time points that best capture remaining cognitive functions thereby minimising the risk of misdiagnoses.

Beyond this, examining circadian processes may also provide targets for therapeutic interventions such as light stimulation, which has proven successful in individuals with e.g. circadian sleep disorders. Interestingly, analyses with Lomb-Scargle periodograms revealed significant circadian rhythmicity in all patients (range 23.5-26.3h).

We found that especially scores on the arousal subscale of the Coma Recovery Scale-Revised (CRS-R) were closely linked to the integrity of circadian variations in body temperature.

Finally, we piloted whether bright light stimulation could boost circadian rhythmicity and found positive evidence in two out of eight patients.

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Late Risers Eat More Fat and Sugar In Evening

MedicalResearch.com Interview with:
Mirkka Maukonen

MSc (nutrition), PhD Candidate
the National Institute for Health and Welfare, Department of Public Health Solutions
Helsinki, Finland

MedicalResearch.com: What is the background for this study?

Response: Recent literature has highlighted the importance of sleep and circadian rhythms in development of obesity and metabolic dysfunctions. Furthermore, it has been suggested that in addition to quality of the diet also meal timing may play role in development of obesity. For example, skipping breakfast and eating at later times in the evening have been associated with higher BMI. However, little is known about how the timing of circadian rhythms (chronotype) affects timing of energy intake and its association with metabolic health.

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Morning People May Make More Mistakes After A Long Day

MedicalResearch.com Interview with:

Dr. Nicola Barclay, BA(Hons), MSc, PhD. Lecturer in Sleep Medicine Sleep and Circadian Neuroscience Institute (SCNi) Nuffield Department of Clinical Neurosciences Sir William Dunn School of Pathology University of Oxford

Dr. Nicola Barclay

Dr. Nicola Barclay, BA(Hons), MSc, PhD.
Lecturer in Sleep Medicine
Sleep and Circadian Neuroscience Institute (SCNi)
Nuffield Department of Clinical Neurosciences
Sir William Dunn School of Pathology
University of Oxford

MedicalResearch.com: What is the background for this study?

Response: We know that extreme sleep deprivation impairs our cognitive functions, particularly attention. This impairment in attention is likely to be driven by physiological mechanisms that change across the waking day (increasing sleep pressure), but also by factors associated with our biological clock. The timing of physiological processes particularly related to attention differ between morning and evening type people (our so called early morning larks and night owls), and so we hypothesised that morning and evening types would differ in their impairments in attention at different times of day, prior to and following 18 hours of sustained wakefulness.

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Electric Lights Disrupts Human Circadian Rhythm

MedicalResearch.com Interview with:
Richard G. Stevens, Ph.D.,
Professor, Cancer Epidemiologist
UConn Health

Medical Research: What is the background for this study? What are the main findings?

Dr. Stevens: Since first introducing the concept of a possible connection between exposure to light at night and breast cancer in the mid-80s, we’ve seen growing evidence of how artificial light can suppress the circadian hormone melatonin and bring about physiological changes.

The extent of this “circadian disruption” varies by the type of light and the time of day. Humans evolved with a body clock that followed the solar clock. Nature intended us to be awake in daylight and at rest in the dark of night. Therefore, the intense, short-wavelength light of the sun in the morning triggers us to become awake and alert, just as the absence of sunlight in the evening allows our body to produce melatonin. Even with the use of fire to provide light in the evening, the circadian impact was relatively minimal because of firelight’s place on the red end of the visible spectrum.

Humans survived under this simple formula for many thousands of years. Then electric light started to take an increasingly strong foothold in everyday life. Today we are typically surrounded at all hours of the day and night by artificial light – in many cases it’s not bright enough during the day to match the sun, and it’s too bright at night to be conducive to the natural sleep/wake cycle. Think computer screens, tablets, smart phones, e-readers, etc. These devices emit enough short-wavelength, or blue, light to disrupt our body clocks in the evening. So do fluorescent and LED lights.

Our paper – I worked with Dr. Yong Zhu from Yale on this – represents a new analysis and synthesis of what we know up to now on the effect of lighting on our health. We don’t know for certain, but there’s growing evidence that the long-term implications of this may have ties to breast cancer, obesity, diabetes, and depression, and possibly other cancers.

Exposure to electric light  started about 130 years ago,  which is a tiny period of time in evolutionary terms. In other words, not long enough to undo human evolution. Continue reading

Shift Work May Reduce Cognitive Performance

Dr. Philip Tucker Department of Psychology | Yr Adran Seicoleg College of Human and Health Sciences | Coleg y Gwyddorau Dynol ac lechyd Swansea University | Prifysgol Abertawe Singleton Park | Parc Singleton Swansea | Abertawe  Medical Research: What is the background for this stuMedicalResearch.com Interview with:
Dr. Philip Tucker
Department of Psychology | Yr Adran Seicoleg
College of Human and Health Sciences | Coleg y Gwyddorau Dynol ac lechyd
Swansea University | Prifysgol Abertawe
Singleton Park | Parc Singleton Swansea | Abertawe

Medical Research: What is the background for this study? What are the main findings?

Dr. Tucker: Shift work, like jet-lag, is known to disrupt workers’ normal circadian rhythms (i.e. their body clocks) and their social life. It is also associated with greater risk of developing ulcers, cardiovascular disease, metabolic syndrome, breast cancer and reproductive problems. Several studies have also shown that shift workers experience heightened fatigue and sleepiness, particularly at night, and this may affect job performance and safety. However, very little is known about the long-term consequences of shift work on cognitive abilities. We followed a large sample of shift workers and non-shift workers over 10 years, testing their cognitive performance every 5 years. We found that the shift workers’ cognitive performance was lower than that of the day workers.  The difference was greatest for those who had worked shifts for more than 10 years. The shift workers’ cognitive function recovered after they quit shift work, but this recovery took at least 5 years from time that they stopped working shifts. The effects could not be attributed to poorer sleep quality among shift workers. Rather, it seems likely that the findings reflect the disruption of the shift workers’ circadian rhythms, which as been shown by other researchers to have an impact on brain structures involved in cognition and mental health over the lifespan.

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High Fat & Sugar Diet May Disrupt Bowel Circadian Rhythm and Bacteria

Dr. Robin Voigt PhD Department of Internal Medicine Division of Gastroenterology Rush University Medical Center Chicago, IllinoisMedicalResearch.com Interview with:
Dr. Robin Voigt PhD
Department of Internal Medicine
Division of Gastroenterology
Rush University Medical Center
Chicago, Illinois

MedicalResearch: What are the main findings of the study? 

Dr. Voigt: We found that chronic circadian rhythm disruption has no effect on the intestinal microbiota when mice are fed a standard chow diet but when combined with a high-fat, high-sugar diet circadian rhythm disruption results in intestinal dysbiosis and an increase in pro-inflammatory bacteria.
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Smoking: Monday Most Popular Day to Quit

MediclResearch.com Interview with:
John W. Ayers, PhD, MA
Graduate School of Public Health
San Diego State University, San Diego, California

MedicalResearch.com: What are the main findings of the study?

Dr. Ayers: Our study, published today in the Journal of the American Medical Association, Internal Medicine was the first to describe daily rhythms in health behaviors.

Because trends in quitting contemplations are usually described annually using telephone surveys, we had to use a novel data source that could capture daily patterns. By monitoring aggregate Internet search queries we can see precisely what the population is thinking about by the content of their queries and that the population is engaged in the issue by searching. We therefore analyzed daily search volumes for smoking cessation queries (e.g., “quit smoking”) in six languages across the entire globe.

We found that people search about quitting smoking more often early in the week, with the highest query volumes on Mondays, using a daily measure representing the proportion of quit smoking searches to all searches. This pattern was consistent across all six languages, suggesting a global predisposition to thinking about quitting smoking early in the week, particularly on Mondays.

English searches, for example, showed Monday query volumes were 11 percent greater than on Wednesdays, 67 percent greater than on Fridays, and 145 percent greater than on Saturdays. In total for all six languages, Monday query volumes were 25 percent higher than the combined mean number of searches for Tuesday through Sunday.

Practically these findings are very meaningful. For example, in English alone there are about 150,000 more quit smoking queries on Monday than on a typical day; about 8,000,000 over an entire year.

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Disruption of Circadian Rhythms and Impaired Intestinal Barrier

Keith Summa MD/PhD Student Northwestern University Feinberg School of Medicine Chicago, Illinois, United States of AmericaMedicalResearch.com Interview with:
Keith Summa MD/PhD Student
Northwestern University Feinberg School of Medicine
Chicago, Illinois, United States of America

 


Disruption of the Circadian Clock in Mice Increases Intestinal Permeability and Promotes Alcohol-Induced Pathology and Inflammation

MedicalResearch.com: What are the main findings of the study?

Answer: The main findings of the study were that disruption of circadian rhythms, which we achieved using independent genetic and environmental strategies in mice, leads to impaired function of the intestinal epithelial barrier. This loss of epithelial barrier integrity, which has been associated with numerous diseases, results in “gut leakiness,” a phenomenon in which endotoxin from gut bacteria can cross the intestinal wall and enter circulation, promoting inflammation. In particular, using in a disease model of gut-derived endotoxemia and inflammation, alcoholic liver disease, we found the circadian disruption interacted with alcohol, leading to increased gut leakiness, inflammation and liver damage.

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