Tuesday, March 26, 2013

Traffic pollution causes as much childhood asthma as passive smoking (?)

This old chestnut seems to have eternal life.  There is no new data here -- just the hoary old epidemiological speculation

A study conducted in 10 European cities found that 14 per cent of chronic childhood asthma was due to pollution near busy roads.  This is similar to the burden linked to inhaling second hand tobacco smoke.

Between 4 per cent and 18 per cent of asthma cases in children are associated with passive smoking.

Lead scientist Dr Laura Perez, from the Swiss Tropical and Public Health Institute in Basel, said: 'Air pollution has previously been seen to trigger symptoms but this is the first time we have estimated the percentage of cases that might not have occurred if Europeans had not been exposed to road traffic pollution.

'In light of all the existing epidemiological studies showing that road traffic contributes to the onset of the disease in children, we must consider these results to improve policy making and urban planning.'

The findings are reported in the online version of the European Respiratory Journal.

Scientists used data from existing studies showing that children exposed to higher levels of traffic pollution also had higher rates of asthma.

A method known as population attributable fractions was employed to assess the impact of pollution near roads.

This calculates the proportional reduction in disease or death that would occur if exposure to a risk factor was lowered.

The results took account of differences in the health of different city populations, as well as other factors including passive smoking and socio-economic background.


Sweet! Just in time for Easter, scientists find chocolate cuts risk of stroke  -- but only if you're lying down

A lot of maybes below

Just in time for Easter, it's the news chocolate lovers have dreamt of – official confirmation that their favourite guilty pleasure can be good for you.

New research shows that eating just a single chocolate bar has a direct effect on the brain and may cut the risk of stroke.

Previous research has shown eating dark chocolate in moderation could be good for you. But the latest study, in the journal Neurology, shows for the first time how chocolate affects blood vessels.

Researchers at Glasgow University measured the speed of blood flowing through the biggest artery in the brain while subjects ate chocolate lying down.

They found that the chocolate had an effect on carbon dioxide levels which affected blood vessels, improved blood flow and, in turn, impacted on brain cells.

Professor Matthew Walters, who led the study, told The Mail on Sunday: 'Consumption of a normal chocolate bar was associated with a change in stiffness of the blood vessels.  'Our data is consistent with a direct effect of chocolate on the brain blood vessels.

'It raises the possibility that there is a direct effect of some component of the chocolate on blood vessels. This is plausible because of the flavonoid molecules contained in chocolate.

'We think a reduction in stroke risk may be caused by chocolate changing how brain blood vessels behave.'

The beneficial flavonoids, found in the cacao plant and others, are antioxidants that contribute to the prevention of heart disease.

However, chocolate  also has a high sugar and fat content which can cause obesity –  a definite risk factor for strokes.

Tom Solomon, professor of neurology at Liverpool University, said: 'We have to take the findings with caution.'


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