Blood vessel width linked to IQ
Researchers from Duke University contend that the width of the blood vessels in a person's retina can be an indicator for IQ. Their study linked brain health and vascular health, where those with smaller retinal vessels scored higher in IQ tests than those with wide blood vessels in the eye.
Through non-invasive digital retinal imaging, the researchers were able to evaluate the small blood vessels in the retina, which have similar size, structure and function to those in the brain. So analyzing retinal blood vessels could help scientists evaluate brain health.
The study evaluated 1,000 people born between April 1972 and March 1973 – making them all 38 years old at the time of this study. People with wide retinal venules, on average, scored lower on IQ tests at the age of 38 than those with small venules. The study also included tests for memory, verbal comprehension, executive function and perceptual reasoning, where the wide-vessels group scored lower as well.
The researchers also found that people with wide blood vessels had a lower IQ when they were kids, and that the association between vascular health and IQ may begin years before any signs of age-related mental decline.