(Press-News.org) [Sedentary behaviour and life expectancy in the USA: a cause-deleted life table analysis doi 10.1136/bmjopen-2012-000828]
Restricting the amount of time spent seated every day to less than 3 hours might boost the life expectancy of US adults by an extra 2 years, indicates an analysis of published research in the online journal BMJ Open.
And cutting down TV viewing to less than 2 hours every day might extend life by almost 1.4 years, the findings suggest.
Several previous studies have linked extended periods spent sitting down and/or watching TV to poor health, such as diabetes and death from heart disease/stroke.
The researchers used data collected for the National Health and Nutrition Examination Survey (NHANES) for 2005/6 and 2009/10, to calculate the amount of time US adults spent watching TV and sitting down on a daily basis.
NHANES regularly surveys a large representative sample of the US population on various aspects of their health and lifestyle.
They trawled the research database MEDLINE, looking for published studies on sitting time and deaths from all causes, and pooled the different relative risk data from the five relevant studies, involving almost 167,000 adults. The database was then reanalysed, taking account of age and sex.
They combined these data and the NHANES figures to come up with a population attributable fraction (PAF) - an estimate of the theoretical effects of a risk factor at a population, rather than an individual level - to calculate the number of deaths associated with time spent sitting down.
The PAFs for deaths from all causes linked to sitting time and TV viewing were 27% and 19%, respectively.
The results of life table analyses indicates that cutting the amount of time spent sitting down every day to under three hours would add an extra two years to life expectancy.
Similarly, restricting time spent watching TV to under two hours daily would extend life expectancy by an extra 1.38 years.
The authors emphasise that their analysis assumes a causal association rather than proving that there is one. But they point to the evidence showing the detrimental effect of a sedentary lifestyle on health.
And they caution that their findings should not be interpreted as meaning that someone who leads a more sedentary lifestyle can expect to live two or 1.4 years less than someone who is more active.
"The results of this study indicate that extended sitting time and TV viewing may have the potential to reduce life expectancy in the USA," they write.
"Given that the results from objective monitoring of sedentary time in NHANES has indicated that adults spend an average of 55% of their day engaged in sedentary pursuits, a significant shift in behaviour change at the population level is required to make demonstrable improvements in life expectancy," they conclude.
Further research will be required before recommendations on safe levels of sedentary behaviour can be made, they add.
INFORMATION: END
Nearly a third of adults with the most common type of brain cancer develop recurrent, invasive tumors after being treated with a drug called bevacizumab. The molecular underpinnings behind these detrimental effects have now been published by Cell Press in the July issue of Cancer Cell. The findings reveal a new treatment strategy that could reduce tumor invasiveness and improve survival in these drug-resistant patients.
"Understanding how and why these tumors adopt this invasive behavior is critical to being able to prevent this recurrence pattern and maximizing the benefits ...
Investigators reporting in the July issue of the Cell Press journal Cancer Cell have found that blocking a fundamental process deep within cancer cells can selectively kill them and spare normal cells.
For more than a century, clinicians have known that abnormalities of the nucleolus—a small, rounded mass within the cell nucleus—can be diagnostic for cancer. The nucleolus is where certain genes are read to form the components of ribosomes, the cellular machines that make proteins. While abnormalities in the nucleolus are known to be diagnostic for cancer, researchers ...
Stem cells that come from a specific part of the developing brain help fuel the growth of brain tumors caused by an inherited condition, researchers at Washington University School of Medicine in St. Louis report.
Scientists showed in mice that disabling a gene linked to a common pediatric tumor disorder, neurofibromatosis type 1 (NF1), made stem cells from one part of the brain proliferate rapidly. But the same genetic deficit had no effect on stem cells from another brain region.
The results can be explained by differences in the way stem cells from these regions ...
So far it has seemed an irreparable limitation of human perception that we strain to perceive things in the very rapid succession of, say, less than half a second. Psychologists call this deficit "attentional blink." We'll notice that first car spinning out in our path, but maybe not register the one immediately beyond it. It turns out, we can learn to do better after all. In a new study researchers now based at Brown University overcame the blink with just a little bit of training that was never been tried before.
"Attention is a very important component of visual perception," ...
NEW YORK, 9 July 2012—Punitive laws and human rights abuses are costing lives, wasting money and stifling the global AIDS response, according to a report by the Global Commission on HIV and the Law, an independent body of global leaders and experts. The Commission report, "HIV and the Law: Risks, Rights and Health," finds evidence that governments in every region of the world have wasted the potential of legal systems in the fight against HIV. The report also concludes that laws based on evidence and human rights strengthen the global AIDS response - these laws exist and ...
A team of scientists led by Assistant Professor Ganesh S Anand and Professor Linda J. Kenney from the National University of Singapore (NUS) Department of Biological Sciences (DBS) and the Mechanobiology Institute (MBI) has discovered how bacteria respond to salts in their environment and the ways in which salts can alter the behaviour of specialised salt sensor bacterial proteins.
This novel finding sheds light on how microbes detect levels of salts or sugars in their watery environments – a problem in biology that has been studied for more than 30 years.
The NUS ...
Rice consumers concerned about reports that rice is linked to diabetes can rest assured that rice can be part of a healthy diet, with scientists finding that the glycemic index (GI) of rice varies a lot from one type of rice to another, with most varieties scoring a low to medium GI.
The findings of the research, which analyzed 235 types of rice from around the world, is good news because it not only means rice can be part of a healthy diet for the average consumer, but it also means people with diabetes, or at risk of diabetes, can select the right rice to help maintain ...
Researchers at the RUB and from Berkeley have used metal complexes to modify peptide hormones. In the Journal of the American Chemical Society, they report for the first time on the three-dimensional structure of the resulting metal-peptide compounds. "With this work, we have laid the molecular foundation for the development of better medicines" says Prof. Raphael Stoll from the Faculty of Chemistry and Biochemistry at the Ruhr-University. The team examined hormones that influence the sensation of pain and tumour growth.
Peptide hormones have many functions in the body
Hormones ...
Photographs of faces may not be adequate proof of a person's identity and this could have serious implications for the accuracy of passport photographs in determining identity. Research funded by the Economic and Social Research Council (ESRC) shows that an image of a person may look strikingly different from one image to the next. We are told not to smile in our passport photos as a smile distorts the face; but the opposite may actually be true, and a poker face may be the one which distorts normal facial features.
Dr Rob Jenkins and his team at the University of Glasgow ...
Robust evidence exists for some wound care interventions, but there are still gaps in current knowledge requiring international consensus and further high-level clinical evidence, according to a paper published online by BJS, the British Journal of Surgery.
Researchers analysed the findings of 44 Cochrane Systematic Reviews (CSRs) published by the Cochrane Wounds and Peripheral Vascular Disease Groups up to June 2011. The reviews covered CSRs on acute wounds and chronic wounds such as venous, pressure, diabetic and arterial ulcers.
This enabled them to identify a number ...
