IQ is the strongest predictor of heart disease, second only to smoking, reports a large study funded by Britain’s Medical Research Council.
People with lower intelligence scores — as reflected by low results on written or oral tests of IQ — had higher rates of heart disease and death than all other risk factors except smoking, it found.
According to the study, published in the European Journal of Cardiovascular Prevention and Rehabilitation, established risk factors, which include obesity and high cholesterol, were not part of the top five risk factors (see box).
For the study, 1,145 men and women aged around 55. Data was collected for height, weight, blood pressure, smoking habits, physical activity, education and occupation, while IQ was assessed using a standard test of general intelligence.
“IQ is not inherent and often indicates inequalities in social status, education and experience, which influence lifestyle choices. Our study of 19,973 people across 10 centres in India also linked higher education and income to lower cardiovascular risk,” said senior cardiologist Dr K. Srinath Reddy, president, Public Health Foundation, India. His study was published in the Proceedings of National Academy of Sciences 2007.
Higher education and income — and now intelligence — are associated with healthy behaviour such as exercise and healthy diets, all of which lower risk factors such as obesity, high blood pressure and elevated blood cholesterol levels.
“People with lower IQ are more likely to be less educated and poor with lower access to health promoting knowledge... This study underlines the need to fast-track health literacy, not just in urban areas but also in semi-urban areas and villages where lifestyle disorders such as heart disease and diabetes are rising faster than in urban centres,” said Dr Reddy.