How excess holiday eating disturbs your 'food clock'
(Medical Xpress)—If the sinful excess of holiday eating sends your system into butter-slathered, brandy-soaked overload, you are not alone: People who are jet-lagged, people who work graveyard shifts and plain-old late-night snackers know just how you feel.
All these activities upset the body's "food clock," a collection of interacting genes and molecules known technically as the food-entrainable oscillator, which keeps the human body on a metabolic even keel. A new study by researchers at UCSF is helping to reveal how this clock works on a molecular level.
Published this month in the journal Proceedings of the National Academy of Sciences, the UCSF team has shown that a protein called PKCγ is critical in resetting the food clock if our eating habits change.
The study showed that normal laboratory mice given food only during their regular sleeping hours will adjust their food clock over time and begin to wake up from their slumber, and run around in anticipation of their new mealtime. But mice lacking the PKCγ gene are not able to respond to changes in their meal time – instead sleeping right through it.
The work has implications for understanding the molecular basis of diabetes, obesity and other metabolic syndromes because a desynchronized food clock may serve as part of the pathology underlying these disorders, said Louis Ptacek, MD, the John C. Coleman Distinguished Professor of Neurology at UCSF and a Howard Hughes Medical Institute Investigator.
It may also help explain why night owls are more likely to be obese than morning larks, Ptacek said.
"Understanding the molecular mechanism of how eating at the "wrong" time of the day desynchronizes the clocks in our body can facilitate the development of better treatments for disorders associated with night-eating syndrome, shift work and jet lag," he added.
Resetting the Food Clock
Look behind the face of a mechanical clock and you will see a dizzying array of cogs, flywheels, reciprocating counterbalances and other moving parts. Biological clocks are equally complex, composed of multiple interacting genes that turn on or off in an orchestrated way to keep time during the day.
In most organisms, biological clockworks are governed by a master clock, referred to as the "circadian oscillator," which keeps track of time and coordinates our biological processes with the rhythm of a 24-hour cycle of day and night.
Life forms as diverse as humans, mice and mustard greens all possess such master clocks. And in the last decade or so, scientists have uncovered many of their inner workings, uncovering many of the genes whose cycles are tied to the clock and discovering how in mammals it is controlled by a tiny spot in the brain known as the "superchiasmatic nucleus."
Scientists also know that in addition to the master clock, our bodies have other clocks operating in parallel throughout the day. One of these is the food clock, which is not tied to one specific spot in the brain but rather multiple sites throughout the body.
The food clock is there to help our bodies make the most of our nutritional intake. It controls genes that help in everything from the absorption of nutrients in our digestive tract to their dispersal through the bloodstream, and it is designed to anticipate our eating patterns. Even before we eat a meal, our bodies begin to turn on some of these genes and turn off others, preparing for the burst of sustenance – which is why we feel the pangs of hunger just as the lunch hour arrives.
Scientist have known that the food clock can be reset over time if an organism changes its eating patterns, eating to excess or at odd times, since the timing of the food clock is pegged to feeding during the prime foraging and hunting hours in the day. But until now, very little was known about how the food clock works on a genetic level.
What Ptacek and his colleagues discovered is the molecular basis for this phenomenon: the PKCγ protein binds to another molecule called BMAL and stabilizes it, which shifts the clock in time.
More information: The article, "PKCγ participates in food entrainment by regulating BMAL1" is authored by Luoying Zhang, Diya Abrahama, Shu-Ting Lin, Henrik Oster, Gregor Eichele, Ying-Hui Fu, and Louis J. Ptácek and appears in the Proceedings of the National Academy of Sciences. www.pnas.org/conte… 679.abstract
Journal reference: Proceedings of the National Academy of Sciences
Provided by University of California, San Francisco
- 'Wrong'-time eating reduces fertility in fruit flies Jun 07, 2011 | not rated yet | 0
- Scientists redraw the blueprint of the body's biological clock Apr 06, 2012 | not rated yet | 0
- Experimental work proves theory that circadian body clock requires delay to function properly Mar 25, 2011 | not rated yet | 0
- Feeding the clock: Cycles of feeding and fasting drive circadian gene expression in the liver Nov 25, 2009 | not rated yet | 0
- Clocking in and out of gene expression Jun 14, 2007 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
How can there be a term called "intestinal metaplasia" of stomach
8 hours ago Hello everyone, Ok Stomach's normal epithelium is simple columnar, now in intestinal type of adenocarcinoma of stomach it undergoes "intestinal...
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013 From pressure-volume curve of the lung and chest wall (attached photo), I don't understand why would the elastic recoil pressure of the lung is...
If you became brain-dead, would you want them to pull the plug?
May 17, 2013 I'd want the rest of me to stay alive. Sure it's a lousy way to live but it beats being all-the-way dead. Maybe if I make it 20 years they'll...
MRI bill question
May 15, 2013 Dear PFers, The hospital gave us a $12k bill for one MRI (head with contrast). The people I talked to at the hospital tell me that they do not...
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013 As an experiment, for the past few months I've been consuming at least one portion of Jell-O or unflavored Knox gelatin per day. I'm 64, in very...
Alcohol and acetaminophen
May 13, 2013 Edit: sorry for the typo in the title , can't edit I looked around on google quite a bit and it's very hard to find precise information on the...
- More from Physics Forums - Medical Sciences
More news stories
Widely available in pharmacies and health stores, phosphatidylserine is a natural food supplement produced from beef, oysters, and soy. Proven to improve cognition and slow memory loss, it's a popular treatment for older ...
Medical research 3 hours ago | 5 / 5 (1) | 0 |
Researchers at Emory University have identified a protein that stimulates a pair of "orphan receptors" found in the brain, solving a long-standing biological puzzle and possibly leading to future treatments for neurological ...
Medical research 3 hours ago | not rated yet | 0 |
Australian scientists have charted the path of insulin action in cells in precise detail like never before. This provides a comprehensive blueprint for understanding what goes wrong in diabetes.
Medical research 4 hours ago | 4.5 / 5 (2) | 0 |
Researchers at the University of Illinois at Chicago College of Medicine will study gender differences in how the heart uses and stores fat—its main energy source—and how changes in fat metabolism play ...
Medical research 6 hours ago | not rated yet | 0
Nearly 20 percent of kidneys that are recovered from deceased donors in the U.S. are refused for transplant due to factors ranging from scarring in small blood vessels of the kidney's filtering units to the organ going too ...
Medical research 23 hours ago | 5 / 5 (2) | 0 |
Researchers at USC have found that a class of pharmaceuticals can both prevent and treat Alzheimer's Disease in mice.
1 hour ago | not rated yet | 0 |
Variation in the gene MUC5B among patients with idiopathic pulmonary fibrosis was associated with improved survival, according to a study published online by JAMA. The study is being released early online to coincide with i ...
11 minutes ago | not rated yet | 0
As many as 35 percent of Mexican young adults may have a genetic predisposition for obesity, said a University of Illinois scientist who conducted a study at the Universidad Autónoma de San Luis Potosί.
14 minutes ago | not rated yet | 0
A study of veterans at high risk for developing lung cancer shows that low-dose computed tomography (LDCT) can be highly effective in helping clinicians spot tiny lung nodules which, in a small number of patients, may indicate ...
8 minutes ago | not rated yet | 0
Among patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) requiring hospital admission, a 5-day glucocorticoid treatment course was non-inferior (not worse than) to a 14-day course with regard ...
8 minutes ago | not rated yet | 0
African-Americans are less likely than whites and women are more likely than men to have had a prior diagnosis of chronic obstructive pulmonary disease (COPD) regardless of their current disease severity, according to a new ...
9 minutes ago | not rated yet | 0