Obesity link found in reduced productivity at the workplace
BEING productive at work can be difficult at this time of year, but maybe even more so for obese workers. In the JournalofOccupational andEnvironmentalMedicine this week, researchers report that moderately to extremely obese people have reduced productivity in manual jobs compared to nonobese employees. The cost of this lower performance could reach thousands of dollars per year for every obese employee, leading to calls for more workplace programs targeting weight loss. Various aspects of productivity, including time taken to complete tasks and ability to meet physical work demands, were measured in 341 manufacturing employees. According to body mass index measurements, 43 per cent were overweight but not obese, 23 per cent were mildly obese and 13 per cent were moderately to extremely obese. Healthrelated losses in productivity averaged 4.2 per cent for workers with moderate to severe obesity, which was 1.8 per cent higher than for other employees. JOccupEnvironMed 2007;49:1317-1324 (Cawley J, et al) WALKING and moderate exercise may help to prevent dementia, claims new research in Neurology this week. A total of 749 men and women aged 65 and older took part in the study. They were surveyed about their levels of physical activity, including time spent walking, climbing stairs, doing housework and gardening. Over the next four years, 54 of the participants developed Alzheimer’s disease and 27 developed dementia. Those with the highest physical activity levels were 24 per cent less likely to develop dementia than those with the lowest levels. When the different types of exercise were considered separately, researchers found walking provided the same level of protection against dementia as more demanding activities. The authors suggest exercise may protect the brain by improving its blood flow. Neurology 2007;doi:10.1212/ 01.wnl.0000296276.50595.86 (Ravaglia G, et al) MARIJUANA is well-known to increase appetite, and it does this by stimulating receptors in the brain. Now scientists have designed a new drug that blocks these receptors and suppresses appetite, leading to significant weight loss in obese people in just 12 weeks. The drug, called taranabant, has been tested in people for the first time, and the results are reported in the current issue of Cell Metabolism. The trial involved 533 obese patients, who were randomly divided into five groups and given 0.5, 2, 4 or 6 mg per day of taranabant or a placebo for 12 weeks. Compared to the placebo, taranabant caused significant weight loss at all of the doses studied. In a shorter trial involving 36 overweight or moderately obese patients, those taking a single dose of 12 mg of taranabant consumed 27 per cent less calories in a 24-hour period than those taking a placebo. At higher doses, side effects of the drug included nausea, vomiting and irritability. CellMetab 2008;7:68-78 (Addy C, et al) AUTISM— a developmental disorder that affects speech, behaviour and social interaction — has no known cause, but some still believe that a preservative found in childhood vaccines may be to blame. Now there is even more evidence that autism is not caused by the preservative, known as thimerosal. In the ArchivesofGeneral Psychiatry this week, researchers report that autism cases in California continued to increase, even after thimerosal was removed from childhood vaccines. Researchers studied the prevalence of autism in children born in California between 1993 and 2003. While thimerosal was eliminated from almost all childhood vaccines by 2001, the rate of autism increased steadily during the study period. For every 1000 children born in 1993, 0.3 had autism at age three, and this increased to 1.3 per 1000 births in 2003. According to the journal’s editor, parents of autistic children should be reassured that the disorder was not caused by immunisations. ArchGenPsychiatry 2008;65:19-24 (Schechter R, et al) SPORT in schools is essential in the fight against adult obesity, according to a new study in the ArchivesofPediatricsandAdolescent Medicine. The study shows that physically active teens are less likely to become overweight young adults, and suggests that more resources be directed towards quality exercise programs for young people. The research team studied 3345 American teens in grades eight to 12. In 1996, participants were interviewed about their participation in physical activities both at school and outside of school. They then reported their height and weight five years later. For every weekday that teens participated in physical education at school, their risk of being overweight as young adults was reduced by 5 per cent. Those who had physical education five days per week had 28 per cent lower risk of being overweight as young adults. ArchPediatrAdolescMed 2008;162:29-33 (Menschik D, et al) AS any parent will tell you, lack of sleep can severely affect the brain’s ability to function properly. But scientists may have found a way to reverse the effects of sleep deprivation. In the latest issue of the JournalofNeuroscience, they report that a naturally occurring protein called orexin-A can help sleep-deprived monkeys to think more clearly. If the findings prove true in humans, orexin-A could be given to shift workers and the military to improve their performance in times of limited sleep. Researchers kept monkeys awake overnight with videos, music and treats, and then tested their brain function. Without sleep, their performance was significantly impaired. But monkeys that received orexin-A via a nasal spray immediately prior to testing showed improved performance, back to their nonsleep-deprived level. JNeurosci 2007;27:14239-14247 (Deadwyler SA, et al) Want to know more? Items are referenced where possible. A reference such as ‘‘ 2007;35:18-25’’ means the source article was published on pages 18-25 in volume number 35 of the publication, in 2007. A doi number or website address is used for research published on a journal’s website.
Walking: Proven to be beneficial