Wednesday, June 18, 2008

How being brainy 'can add 15 years to your life'

There has long been evidence that IQ is in general just one aspect of a syndrome of general biological fitness

It gets you good grades at school, improves your prospects at work and makes you more attractive to the opposite sex. And as if all that weren't enough, being brainy could add 15 years to your life, a study suggests. Researchers found those with rogue copies of a gene linked to intelligence are unlikely to survive beyond the age of 85. However, those blessed with good versions of the gene could live to be 100.

The gene governs an enzyme which destroys a chemical known to dampen brain activity and cause drowsiness. The enzyme - succinic semialdehyde dehydrogenase, or SSADH - also detoxifies the brain by getting rid of excess acid, protecting cells from damage which can accelerate ageing. The gene comes in two common forms, with the so-called 'T' version working 20 per cent less well than the 'C' variety. Previous studies have shown that men and women with two copies of the 'T' version do less well in IQ tests than others. But only now have scientists made the link to life expectancy, this week's New Scientist reports.

The Italian researchers based their findings on a study of 115 elderly men and women. They were asked to complete a test of memory and mental dexterity more usually used to diagnose Alzheimer's disease. The volunteers, who were aged between 65 and 85, had given blood samples to determine which version of the gene they were carrying. Those carrying two copies of the rogue 'T' version of the gene performed significantly worse than the others, echoing the results of the earlier research on young people.

The University of Calabria researchers then used data on how common the versions of the gene were across different age ranges to work out if it was linked with longevity. This showed those carrying two 'T' variants were unlikely to live past 85 - but those with at least one 'C' could expect to live to up to 100. The scientists said that having a double dose of the rogue gene appeared to make people more vulnerable to mental decline in old age, as well as affecting their survival. But they stressed that genes do not tell the whole story.

Professor Giuseppe Passarino said: 'There's no doubt lifestyle such as reading, having challenging work and enriching your cultural life is far more important than having the bad variant.'

Professor Robert Plomin, of the Institute of Psychiatry in London, who in 2004 linked the gene to IQ, said: 'Although the sample size is small...the reported associations with cognitive ability are significant and in line with our previous results.' He added that further studies were needed to confirm the link with longevity.


Coffee may protect the heart, leading experts claim

Some proper caution about the findings expressed below. That coffee is at least not bad for you seems a reasonably firm conclusion, however

Drinking three cups of coffee a day could reduce the risk of women dying from heart disease by a quarter, researchers said today. The team also found that drinking lots of coffee is not harmful, as those who consumed up to six cups a day were not at increased risk of death, as has been suggested previously.

The research published in the journal Annals of Internal Medicine tracked over 84,000 women and 41,000 men for around twenty years. The participants completed questionnaires every two to four years about their coffee intake and other habits including diet, smoking and general health.

Study author Dr Esther Lopez-Garcia, from the School of Medicine at Universidad Autonoma de Madrid in Spain, said: "Coffee consumption was not associated with a higher risk of mortality in middle-aged men and women. The possibility of a modest benefit of coffee consumption on heart disease, cancer, and other causes of death needs to be further investigated."

Women consuming two to three cups of caffeinated coffee per day had a 25 per cent lower risk of death from heart disease during the follow-up period compared with people who did not drink coffee, and an 18 per cent lower risk of death caused by something other than cancer or heart disease. For men, three cups of coffee daily was not linked with either a higher or a lower risk of death.

While accounting for other risk factors, such as body size, smoking, diet, and specific diseases, the researchers found that people who drank more coffee were less likely to die during the follow-up period. This was mainly because of lower risk for heart disease deaths among coffee drinkers. The researchers found no association between coffee drinking and cancer deaths. The lower risk of death did not appear to be linked to caffeine as those who drank decaffeinated coffee also had lower death rates than those who did not drink coffee.

The editors of the journal said the findings should be read with caution as the design of the study does not make it certain that coffee decreases the chances of dying sooner than expected as something else about coffee drinkers might be protecting them. Also the researchers relied on self-reporting of consumption which can increase the chance of errors.


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