(Press-News.org) Shift work, like chronic jet lag, is known to disrupt the body's internal clock (circadian rhythms), and it has been linked to a range of health problems, such as ulcers, cardiovascular disease, metabolic syndrome, and some cancers.
But little is known about its potential impact on brain function, such as memory and processing speed.
The researchers therefore tracked the cognitive abilities of more than 3000 people who were either working in a wide range of sectors or who had retired, at three time points: 1996; 2001; and 2006.
Just under half (1484) of the sample, which was drawn from the patient lists of three occupational health doctors in three different regions in southern France, had worked shifts for at least 50 days of the year.
Participants were aged exactly 32, 42, 52 and 62 at the time of the first set of tests, which aimed to assess long and short term memory; processing speed; and overall (global) cognitive abilities. In all, 1197 people were assessed at all three time points.
Around one in five of those in work (18.5%) and a similar proportion of those who had retired (17.9%) had worked a shift pattern that rotated between mornings, afternoons, and nights.
The first set of analyses looked at whether any abnormal working hours were associated with a decline in cognitive abilities.
The data showed that those who currently, or who had previously, worked shifts had lower scores on memory, processing speed, and overall brain power than those who had only worked normal office hours.
The second set of analyses looked at the impact of working a rotating shift pattern and found that compared with those who had never worked this type of shift, those who had, and had done so for 10 or more years, had lower global cognitive and memory scores—equivalent to 6.5 years of age related cognitive decline.
Finally, the researchers looked at whether stopping shift work was linked to a recovery in cognitive abilities.
The results indicated that it was possible to regain cognitive abilities after stopping shift work, but that this took at least five years, processing speeds excepted.
This is an observational study so no definitive conclusions can be drawn about cause and effect, but the disruption of the body clock as a result of shiftwork could generate physiological stressors, which may in turn affect the functioning of the brain, suggest the researchers.
Other research has also linked vitamin D deficiency caused by reduced exposure to daylight, to poorer cognition, they point out.
"The cognitive impairment observed in the present study may have important safety consequences not only for the individuals concerned, but also for society as a whole, given the increasing number of jobs in high hazard situations that are performed at night," warn the researchers.
At the very least the findings suggest that monitoring the health of people who have worked shift patterns for 10 years would be worth while, they say.
INFORMATION:
Around one in five patients with chest pain will have no obvious signs of coronary artery disease after investigation, and their symptoms are unlikely to have a physical cause.
But it is not always clear who these patients are, and they often undergo extensive and expensive tests to find out that nothing is wrong with their hearts.
The German authors therefore wanted to test the prevalence of physical and mental symptoms in 253 patients who had been investigated for chest pain/shortness of breath/palpitations and found to have no coronary artery disease.
The type ...
Philadelphia, November 4, 2014 -- In a new evidence-based clinical practice guideline published today in Annals of Internal Medicine, the American College of Physicians (ACP) recommends that people who have had a kidney stone increase their fluid intake to achieve at least two liters of urine per day to prevent another kidney stone from forming. If increased fluid intake fails to reduce the formation of stones, ACP recommends adding medication with a thiazide diuretic, citrate, or allopurinol.
"Increased fluid intake spread throughout the day can decrease stone recurrence ...
1. ACP kidney stone guidelines offer another reason to drink more water, less soda
Dietary changes including increased fluid intake are among recommendations in ACP's new evidence-based guideline
People who have had a kidney stone should increase their fluid intake to achieve at least two liters of urine per day to prevent a recurrence, according to a new evidence-based clinical practice guideline from the American College of Physicians (ACP) being published in Annals of Internal Medicine. A kidney stone occurs when tiny crystals in urine stick together to form a stone. ...
The growing epidemic of obesity across the world is associated with an equivalent increase in type-2 diabetes, which results from the body's ineffective use of insulin. Obese people often develop inflammation in their fat tissue, which, in turn, can reduce the sensitivity of fat cells to insulin, resulting in type-2 diabetes. EPFL scientists, working with researchers from Italy and the Netherlands, have shown that bile acids activate a little-known receptor to overcome the loss of insulin sensitivity, forming the basis for a new class of drug against type-2 diabetes. The ...
Food allergies are on the rise in the U.S. and other developed countries. In patients, food allergies appear as a variety of symptoms, ranging from mild skin inflammation to severe asthma. Recent studies suggest that contact between inflamed skin and food proteins may trigger food allergy development. A new study in the Journal of Clinical Investigation provides a link between skin sensitization, gastrointestinal inflammation, and food allergy. Using a mouse model, Steven Ziegler and colleagues at the Benaroya Research Institute found that skin exposure to a combination ...
General anesthesia results in expended cognitive decline for many individuals following surgical procedure. Memory deficits can last for months and affect patient outcome and quality of life. Patient age, duration of surgery, and surgical trauma are all risk factors for postoperative cognitive impairment. A new study in the Journal of Clinical Investigation demonstrates that general anesthesia results in sustained activation of receptors that inhibit brain function. Beverly Orser and colleagues at the University of Toronto found that a single dose of anesthetic impaired ...
Researchers at the University of Toronto's Faculty of Medicine have shown why anesthetics can cause long-term memory loss, a discovery that can have serious implications for post-operative patients.
Until now, scientists haven't understood why about a third of patients who undergo anesthesia and surgery experience some kind of cognitive impairment—such as memory loss—at hospital discharge. One-tenth of patients still suffer cognitive impairments three months later.
Anesthetics activate memory-loss receptors in the brain, ensuring that patients don't remember ...
The microbes living in people's guts are much less diverse than those in humans' closest relatives, the African apes, an apparently long evolutionary trend that appears to be speeding up in more modern societies, with possible implications for human health, according to a new study.
Based on an analysis of how humans and three lineages of ape diverged from common ancestors, researchers determined that within the lineage that gave rise to modern humans, microbial diversity changed slowly and steadily for millions of years, but that rate of change has accelerated lately ...
A study to be released in the November issue of Health Affairs shows that integrating community housing data on such code violations as mold and cockroaches with health data can identify at-risk geographical areas of medical concern and help target patients for medical interventions.
Researchers from Cincinnati Children's Hospital Medical Center used geocoding, or mapping, to examine associations between housing code violations and children's health. They found that children hospitalized for asthma are nearly twice as likely to be rehospitalized or to revisit the emergency ...
PITTSBURGH, Nov. 3, 2014 – Patients with atrial fibrillation who take the blood thinner dabigatran are at greater risk for major bleeding and gastrointestinal bleeding than those who take warfarin, according to a new study by researchers at the University of Pittsburgh Graduate School of Public Health.
The findings, based on Medicare claims data and published today in JAMA Internal Medicine, indicate greater caution is needed when prescribing dabigatran to certain high-risk patients.
Atrial fibrillation, an arrhythmia in which the heart's upper chambers irregularly ...
