Wednesday, February 10, 2010

Low IQ correlated with cardiovascular disease?   posted by Razib @ 2/10/2010 01:03:00 AM

Second Only to Cigarette Smoking in Large Population Study:
While lower intelligence scores -- as reflected by low results on written or oral tests of IQ -- have been associated with a raised risk of cardiovascular disease, no study has so far compared the relative strength of this association with other established risk factors such as obesity, smoking and high blood pressure. Now, a large study funded by Britain's Medical Research Council, which set out to gauge the relative importance of IQ alongside other risk factors, has found that lower intelligence scores were associated with higher rates of cardiovascular disease and total mortality at a greater level of magnitude than found with any other risk factor except smoking.


The relative strengths of the association were measured by an "index of inequality," which summarised the relative risk of a health outcome (cardiovascular death) in the most disadvantaged (high risk) people relative to the most advantaged (low risk). This relative index of inequality for the top five risk factors was found to be 5.58 for cigarette smoking, 3.76 for IQ, 3.20 for low income, 2.61 for high systolic blood pressure, and 2.06 for low physical activity.

The investigators note "a number of plausible mechanisms" whereby lower IQ scores could elevate cardiovascular disease risk, notably the application of intelligence to healthy behaviour (such as smoking or exercise) and its correlates (obesity, blood pressure). A further possibility, they add, "is that IQ denotes 'a record' of environmental insults" (eg, illness, sub-optimal nutrition) accumulated throughout life.

Related, Calorie Posting in Chain Restaurants:
...In Table 5 we present estimates of how the effect of calorie posting on calories per transaction differs across sub-groups. The estimates in column (1) are based on the transaction data. Although the anonymous transaction data contain no information about the demographics of the consumers who made each transaction, we do know the store location of each transaction, and census data provide us with zip-level demographics. Using this information, we find that the decrease in calories per transaction was larger in zips with higher income and in zips with more education (i.e., more people with college degrees).