Are Vegetarians Smarter?

Scientists in UK have found there’s an association between childhood IQ and adult vegetarianism. This finding may raise more questions than it answers. In a report in the British Medical Journal, 8,000 children aged 10 entered a study when their mental ability (IQ) was assessed. Their diet was assessed when they were 30 years old. At that time, over 300 of them were self-reported vegetarians (actually, 4.5%).

Vegetarians were more likely to be female (3:1), come from the highest social class, and remain in this class as adults. They were also more likely to be academic achievers – nearly half had degrees or diplomas.

After making adjustments statistically for all these factors, it was found that a 15-point increase in childhood IQ was associated with a 20% increased likelihood of the child growing up into a vegetarian. ‘Vegans’ (who eat no animal products at all, not even eggs and milk) had an average childhood IQ about 10 points lower than other vegetarians (95.1 vs. 104.8).

What’s the cause for this association? Are smart kids so smart they choose a healthier diet as they grow up? After all, children of higher intelligence are less likely to smoke as adults because of the health risks. Do the children of wealthier parents have ‘better’, or wider, food choices when young, which translate into vegetarianism when they mature? But the study leaves open the possibility that intelligence and vegetarianism are merely expressions of a common genetic factor (or factors) that’s interesting, but unrelated to health . . .