DRIVERS who use a cellular telephone, even with a “hands-free” device, suffer from a kind of tunnel vision that endangers themselves and others, US researchers said.
Legislation that seeks to make mobile telephone use by drivers safer by mandating the use of a hands-free device may be providing a false sense of security, they warned.
“Sometimes you have to actually do the silly study that shows the obvious,” David Strayer, an associate professor of psychology at the University of Utah, who led the study, said.
Strayer, whose team has done a series of studies on cellphone use while driving, set up a driving simulator and put 20 volunteers in it. Sometimes they used a cellphone and sometimes they did not. Their reaction time, driving style and performance were monitored.
Strayer’s group said use of a cellphone clearly distracted the drivers.
The finding adds to a series of similar studies – most notably a 1997 New England Journal of Medicine report that found talking on a phone while driving quadrupled the risk of accident.
“People, when on a cellphone compared to when they weren’t, overall their reactions were slower,” Strayer said. “They got into more rear-end collisions. They just kind of had a sluggish style that was unresponsive to unpredictable events like a car breaking down in front of them, a light changing and things like that.”
There was no difference, Strayer said, between using a hands-free or a hand-held cellphone.
“You were impaired in both cases,” he said. “That suggests to us that whatever legislation may be put into place might give people a false sense of security.”
Perhaps even more disturbing was the finding that the volunteers did not realise they were driving badly.
“We asked people afterward how they felt they performed and they usually felt they performed without impairment and, in some cases, thought they drove better when on the cellphones,” Strayer said.
Strayer wanted to know why talking on a cellphone had such a profound effect on drivers, so his team set up a second experiment.
“We used an eye tracker – a really precise device that allows us to see where someone is looking,” he said.
They found that while the drivers looked at objects, in this case billboards, if they had been talking on a cellphone at the time they could not remember having seen them.
“There is a kind of a tunnel vision – you aren’t processing the peripheral information as well,” Strayer said. “Even though your eyes are looking right at something, when you are on the cellphone, you are not as likely to see it.”
This included road signs, other vehicles and traffic lights. “This is a variant of something called inattention blindness,” Strayer said.
Tests showed this kind of inattention did not affect drivers who were listening to music, to audio books or talking with a passenger in the car. – Reuters
Sleep link to heart disease
WOMEN who are sleep deprived or who sleep too much run a greater risk of developing coronary heart disease than women who get a regular eight hours of shut-eye a night, according to a study.
Researchers who studied data on more than 71,000 women over a 10-year period reported that the women who got five hours or less of kip a night were 45% more likely to develop narrowed coronary arteries than a control group that got a solid eight hours of repose.
Women who averaged six hours of shut-eye a night had an 18% higher risk compared to the control group, while women who got a regular seven hours of down-time were 9% more likely to develop heart disease than the controls after adjusting for other factors such as smoking or body weight.
Conversely – and somewhat to the researchers’ surprise – women who averaged nine to 11 hours were also at 38% higher risk for the disease, according to the researchers at Boston Brigham and Women’s Hospital.
Previous studies have shown that the effects of short-term sleep deficits include increased blood pressure, heart rate variability, decreased glucose tolerance and increased cortisol levels.
But the Boston researchers noted that little is known about the long-term impact of sleep deficits and oversleeping on overall health, such as the risk for heart attack and coronary heart disease.
Coronary heart disease, caused by the narrowing of the coronary arteries and a common catalyst for heart attacks, is greatly influenced by a variety of lifestyle choices, such as exercise, smoking and diet.
This new study suggests that sleep may weigh into that equation, too, the Boston researchers said.
“This research sends an important message to a population that is spending more and more time working and staying up late watching television or using the Internet. Adequate daily sleep should not be considered a luxury, but an important component of a healthy lifestyle.” – AFP
Predicting heart disease risk
A FAIRLY new test for a protein linked with inflammation can be used to help a doctor decide a patient’s risk of heart disease, heart experts and government health officials said.
They found no reason to recommend the test for C-reactive protein (CRP) for the public, but said it would be useful to help a doctor advise a patient with, for instance, moderately high cholesterol or blood pressure.
The researchers, including a team at the United States Centers for Disease Control and Prevention (CDC), said no one has been able to show that reducing CRP reduces the risk of heart attack or other serious “heart events” – but higher levels are linked with these risks.
“Although our statement identifies a subgroup of patients who may benefit from CRP testing, for most patients the emphasis must remain on detection, treatment and control of the major risk factors, such as high blood pressure, high blood cholesterol, cigarette smoking and diabetes,” Mensah added.
Tests for blood pressure, cholesterol, heart rhythm and blood sugar are often part of a routine visit to the doctor -- especially for patients over 40 and pregnant women. The CDC and American Heart Association team said there is no reason yet to add the CRP test to this list.
But they said the test might be useful when a doctor is uncertain about a patient who is considered an intermediate risk.
A second study showed the CRP test can predict heart disease risk for women with metabolic syndrome – a cluster of symptoms that itself has been shown to predict a high risk of heart disease.
A patient has metabolic syndrome if he or she has three or more of five conditions – abdominal obesity, high triglycerides, low levels of “good” or high density lipoprotein cholesterol, high blood pressure, and high blood sugar.
Dr Paul Ridker and colleagues at Harvard Medical School tested 14,719 healthy women taking part in a larger study. About a quarter of them had metabolic syndrome.
Women with higher CRP levels were twice as likely to suffer heart attacks, strokes and death from cardiovascular disease. – Reuters
THE European Commission said it was ordering a limit to the amount of pigment used in feed to colour salmon, egg yolks and poultry after studies found a high intake could damage human eyesight.
The pigment, canthaxanthin, is used as a feed additive for farmed salmon and poultry to make salmon appear more reddish and chicken skin and egg yolks more yellow.
The European Union executive said consumers had no way of telling if the additive was present as it need not be labelled.
The Commission said the 15 EU member states must limit the use of the pigment by Dec 1.
“Scientific assessments have shown that a high intake of canthaxanthins produces an accumulation of pigments in the retina, affecting the sight,” Commissioner David Byrne said in a statement. “The use of this feed additive is purely cosmetic.”
The Commission found levels of the pigment used by salmon and poultry farmers were too high at up to 80mg per kg of feed. It set maximum levels at 25mg per kg of feed for fish and poultry and 8mg per kg for laying hens. – Reuters
Bad for the bones
ATHLETES may be in top shape but the gruelling physical activity and competition to which they subject themselves increases their risk of suffering bone and joint problems, researchers said.
Footballers are 10 times more likely to develop osteoarthritis in their hip than other men, and long-distance runners are more prone to low-bone mineral density, which can lead to fractures and the brittle-bone disease osteoporosis.
“We suspect it is just the nature of the sport. It is almost analogous to an industrial injury,” said Gordon Shepard, an orthopaedic surgeon at the Royal Bolton Hospital in Lancashire, northern England.
Shepard and his colleagues studied the rate of osteoarthritis in 68 football managers who had been former players and 136 men who had never played football. Their research is reported in The British Journal of Sports Medicine.
They discovered that nine of the former players suffered from osteoarthritis, even if they have not had a serious hip injury, and six of them had had a total of eight hip replacements between them. But there were only two cases of the illness in the non-footballers.
“There was about a 10-fold difference between the ex-professional players and non-professionals,” Shepard added in an interview.
There were not only more cases of the illness among former footballers, they also had hip replacements in their late 30s and early 40s, which is uncommon at such a young age in a small group of people.
Shepard believes that footballers probably sustained minor groin and other injuries which increased the risk of osteoarthritis, an illness in which the joints wear out.
In a separate study in the journal, Dr Melanie Burrows and researchers at the University of East London found that instead of increasing bone mineral density in female athletes, long-distance running lowered it.
By measuring the bone density of 52 women who ran between 5km and 70 kma week, they discovered a link between lower bone density in the spine and hip and running greater distances, even after taking account of differences such as diet, size and age.
But they found that the heavier women in the study, who had more muscle than fat, had a higher bone density, similar to athletes who do weightlifting, gymnastics and volleyball.
“It may not be the exercise mode alone that affects bone mineral density but the force applied to the limbs during such exercise and the resulting effects on body composition,” Burrows said. – Reuters
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