According to a new research published in Psychological Science, the width of blood vessels in the retina may indicate your brain health.

Previous studies have already shown that younger people who score relatively low on IQ tests tend to be poorer and have a shorter lifespan — however, it’s still a matter of debate if this has a physiological cause, or if the lifestyle associated with the lower IQ is simple less healthier. However, in the current study, psychological scientists led by Dr Idan Shalev of Duke University wondered whether intelligence might directly indicate the health of the brain – specifically the health of the system of blood vessels which provide nutrients and oxygen to your brain. In order to investigate this relation, they studied a rather unexpected domain: ophtalmology.

The researchers examined data from participants taking part in the Dunedin Multidisciplinary Health and Development Study, a large health and behavior investigation that takes place in New Zealand and studies over 1000 people. They used a technique called digital retinal imaging. In digital retinal imaging, high-resolution imaging systems are used to take pictures of the inside of your eye, enabling doctors to estimate the health of your retina and helps them to detect and manage such eye and health conditions as glaucoma, diabetes, and macular degeneration.

The findings were intriguing: lower IQ scores were associated with wider retina venules (the very small blood vessel at the back of your eye), even after researchers compensated for other factors, such as lifestyle, general health and environmental risks.

“It’s remarkable that venular caliber in the eye is related, however modestly, to mental test scores of individuals in their 30s, and even to IQ scores in childhood,” Dr Idan Shalev and colleagues said.

The study doesn’t explain why vascular health and cognitive functioning are connected, but researchers are fairly sure that it is somehow connected to the oxygen in the brain.

“Increasing knowledge about retinal vessels may enable scientists to develop better diagnosis and treatments to increase the levels of oxygen into the brain and by that, to prevent age-related worsening of cognitive abilities,” the scientists concluded.

Journal Reference.