Intelligent children may be more likely to be vegetarian as adults,
suggests a recent University of Southampton-led study published online by the
British Medical Journal.
The study, led by Dr Catharine Gale of the University's MRC Epidemiology Resource Centre, looked to see why people with higher IQs appeared to be less likely to suffer from heart disease.
'We examined the records of 8179 men and women aged 30 years, whose IQ had been tested at the age of ten. Twenty years on, 366 (4.5 per cent) of participants said they were vegetarian. Of these, 9 (2.5 per cent) were vegan and 123 (33.6 per cent) stated they were vegetarian but reported eating fish or chicken,' says Dr Gale.
'Those who were vegetarian by the age of 30 had scored five IQ points above average at the age of ten. This can be partly accounted for by better education and higher occupational social class, but it remained statistically significant after adjusting for these factors.'
Recent evidence suggests that vegetarianism may be linked to lower cholesterol levels and a reduced risk of obesity and heart disease. This might help to explain why children who score higher on intelligence tests tend to have a lower risk of coronary heart disease in later life.
'One explanation for the link between higher IQ and vegetarianism may be that brighter children grow up to think more about what they eat, which in some cases has led them to become vegetarians,' continues Dr Gale.
Professor Ian Deary from the University of Edinburgh, one of the study's co-authors, adds: 'As the only member of the research team who has never been a vegetarian I feel bound to emphasise that the link we have found might not be causal. Becoming vegetarian might be one of a number of more or less arbitrary cultural choices that clever people make, some of which might be beneficial to health, and some not.'
Vegetarians were also more likely to be female, to be of higher occupational social class and to have higher academic or vocational qualifications than non-vegetarians, although these differences were not reflected in their annual income, which was similar to that of non-vegetarians.
There was no difference in IQ score between strict vegetarians and
those who said they were vegetarian but who reported eating fish or
chicken.