FIVE THINGS ABOUT INCOME AND BRAIN HEALTH

Young adults who weather substantial pay cuts do worse on brain health assessments in midlife. Researchers in the U.S. collected income data over two decades for 3,287 adults, starting in 1990 when they were 23 to 35 years old.

1 UNSTABLE INCOME, WORSE PROCESSING ABILITY

Researchers assessed income volatility based on how much earnings rose or fell from one year to the next, and also tallied how many times participants’ income dropped by at least 25 per cent. People who experienced greater income volatility and more pay cuts had worse scores for processing speed and executive functioning in cognitive tests in 2010.

2 LESS WHITE MATTER

Brain scans that year also showed reduced connective white matter and worse structural integrity.

3 EDUCATION NOT A FACTOR

Changes in cognitive test scores and brain scans didn’t appear to differ when researchers only looked at participants with the most education.

4 MORE INCOME DROPS WORSE THAN BIG DROP

Almost half the participants, 1,780 people, didn’t have any income drops of 25 per cent or more during the study period. People in this group had average annual income of US$39,681. Another 1,108 people experienced one major income decline during the study period, and this group had average annual income of US$32,253. And 399 individuals with average annual income of US$33,326 experienced two or more substantial income reductions. Having multiple income drops appeared worse for brain health than having a single large drop during the study period.

5 RISK FROM DEPRESSION OR STRESS

The study wasn’t designed to prove whether earnings volatility directly impacts brain health. “Individuals who experience important income fluctuations may be more at risk for cardiovascular risk factors, depression or perceived stress, which are in turn associated with poor cognitive health,” said Adina Zeki Al Hazzouri, a researcher at the Mailman School of Public Health at Columbia University in New York.