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Higher IQ at the age of 10 years is associated with an increased likelihood of being a vegetarian at the age of 30 (odds ratio for one standard deviation increase in childhood IQ score 1.38). This is the finding of a prospective British national cohort study of 8170 men and women aged 30 years. IQ was assessed by tests of mental ability at age 10 years and vegetarianism was self-reported at the age of 30 years. The findings remained statistically significant after adjustment for social class (both in childhood and later), academic or vocational qualifications, and sex. So clever children are more likely to become vegetarians, rather than vegetarians being more likely to become clever.
BMJ, doi:10.1136/bmj.39030.675069.55 (published 15 December 2006).
Fallers, falls and fractures
Most systematic reviews conclude that the evidence is insufficient to support an intervention, or that trials are of poor quality. This one on preventing falls in elderly people in care homes and hospitals based on 43 studies is not much different. Its abstract says, “Meta-analysis for multifaceted interventions in hospital (13 studies) showed a rate ratio of 0.82 (95% CI 0.68 to 0.997) for falls but no significant effect on the number of fallers or fractures. For hip protectors in care homes (11 studies) the rate ratio for hip fractures was 0.67 (0.46 to 0.98), but there was no significant effect on falls and not enough studies on fallers.” Thus there is some evidence that multifaceted interventions and hip protectors are beneficial. However, by the time you read the paper and sort out the effects on falls, fallers and fractures, you realise that you don’t really know what works in these patients.
A retrospective review of 27 children with Sturge–Weber syndrome who underwent surgery for medically resistant epilepsy finds that eight children who had a hemispherectomy (anatomical or functional) had complete resolution of their epilepsy. Of the 19 patients in whom a focal resection was performed, 11 became seizure free. In all, 17 children improved in their developmental status following surgery. The 10 children in whom there was residual disease were more likely to have continuing epilepsy than the nine whose lesions were completely excised.
Lifetime risk of stroke
A prospective analysis of the community-based Framingham Study looks at the long-term trends in the incidence, lifetime risk, severity and 30-day case fatality of stroke in a cohort of 9152 men and women free of stroke at initial examination. It finds that the incidence of stroke has decreased over the past 50 years but the lifetime risk has not reduced to the same degree. The authors say this is perhaps due to improved life expectancy. Participants were followed for up to 50 years over three consecutive periods
Prenatal testing for toxoplasmosis is routinely offered in some countries so that infected mothers can be treated with antibiotics to prevent infecting the fetus. But is such treatment effective? A systematic review of 26 observational studies finds weak evidence for an association between early treatment and reduced risk of congenital toxoplasmosis (which can cause blindness and brain damage). The authors say that their results could be explained by biases in the design and conduct of the studies they looked at, and that the final answer could only come from a large randomised controlled trial.
Folic acid and cognition
Folic acid supplementation for three years can improve some domains of cognitive performance, which tend to decline with age. This is a secondary finding of the randomised controlled trial FACIT (folic acid and carotid intima-media thickness). Participants were 818 men and women aged 50–70 years who took 800 g of folic acid daily and who already had high levels of homocysteine. The authors say that these people were more likely to benefit from folic acid supplementation. The cognition domains that were studied were memory, information processing speed, and sensorimotor speed. Serum folate levels increased and homocysteine levels decreased in participants—as expected.
A group of 16 European population based centres looked at the prevalence of cerebral palsy in very low birth weight babies (less than 1500 g). The birth prevalence fell from 61 per 1000 live born in 1980 to 40 per 1000 infants in 1996. This fall was related to a decrease in bilateral spastic cerebral palsy among infants of birth weight 1000–1499 g. The frequency of cerebral palsy was higher in male than female babies with birth weight between 1000–1499 g (61 vs 50 per 1000 live births) but not in those with birth weight below 1000 g. Changes in the management very low birth weight babies happened in different centres at different times. As a consequence it is not possible to attribute the decline to any particular intervention, say the authors.