Fat linked to loss of intelligence
Sunday, November 12th, 2006It has already been nicknamed the “Homer Simpson effect” - and now research suggests being overweight could affect your intelligence.
A five-year study of more than 2000 middle-aged people has found a possible link between weight and brain function.
Research published in Neurology, the journal of the American Academy of Neurology, found people with a higher Body Mass Index (BMI) scored lower on average in cognitive tests within a sample.
Meanwhile, a separate paper, published in the same journal by Scots researchers, suggests a link between physical and mental fitness.
The findings came in the week that the UK was named the “fat man of Europe” following publication of new figures. The research into the impact of weight upon intelligence was led by Dr Maxime Cournot, of Toulouse University Hospital in France.
Researchers studied 2223 healthy people, aged 32 to 62, who sat four cognitive tests including word learning in 1996 and again in 2001.
Results from a word memory test showed that people with a BMI of 20 - considered to be a healthy level - remembered an average of nine out of 16 words. But people with a BMI of 30 - inside the obese range - remembered an average of just seven out of 16 words.
While those whose BMI changed over the five years did not appear to see any change in their cognitive function, those who started out with a higher BMI did appear to show higher levels of “cognitive decline”, Dr Cournot said. “The findings may be due to a host of factors including the thickening and hardening of cerebral vessels because of obesity or possibly the development of insulin resistance,” said Dr Cournot.
The apparent phenomenon has already been dubbed the “Homer Simpson effect” by some media in North America.
BMI is calculated by setting a person’s weight against their height to produce a single figure.
A link between physical and mental fitness has also been suggested in a Scots study after 460 people who took part in a mental health survey in 1932 when they were 11 years old were re-tested at the age of 79.
Report author Professor Ian Deary, of Edinburgh University, said: “Fitness contributes to better cognitive ability in old age.
“Thus, two people starting out with the same IQ at age 11, the fitter person at age 79 will, on average, have better cognitive function.”
Further research published today shows that overweight workers are often regarded by colleagues as lazy. Many of those questioned by Benenden Healthcare said they knew someone who had been turned down for a job or promotion because of their size.
