Boomers should chow down on leafy greens. Researchers have linked lutein, a pigment in the leaves, with the preservation of “crystallized intelligence,” the ability to use the skills and knowledge acquired over a lifetime. The journal Frontiers in Aging Neuroscience published the results.

Leafy green veggies, and cruciferous vegetables like broccoli, are packed with lutein. The compound accumulates in the brain, becoming embedded in cell membranes where it plays “a neuroprotective role,” University of Illinois graduate student Marta Zamroziewicz said in a university release published on sciencedaily.com. She led the study with psychology professor Aron Barbey. "Previous studies have found that a person's lutein status is linked to cognitive performance across the lifespan," Zamroziewicz said. "Research also shows that lutein accumulates in the gray matter of brain regions known to underlie the preservation of cognitive function in healthy brain aging."

The study enrolled 122 healthy participants ages 65 to 75, who solved problems and answered questions on a standard test of crystallized intelligence. Researchers also collected blood samples to determine blood serum levels of lutein and imaged participants' brains using MRI to measure the volume of different brain structures.

The team focused on parts of the temporal cortex, a brain region that other studies suggest plays a role in the preservation of crystallized intelligence.

Participants with higher blood serum levels of lutein did better on tests of crystallized intelligence. They also tended to have thicker gray matter in the parahippocampal cortex, a brain region that, like crystallized intelligence, is preserved in healthy aging, the researchers said.

"We can only hypothesize at this point how lutein in the diet affects brain structure," Barbey said. "It may be that it plays an anti-inflammatory role or aids in cell-to-cell signaling. But our finding adds to the evidence suggesting that particular nutrients slow age-related declines in cognition by influencing specific features of brain aging." Research has also shown lutein to be critical in maintaining eye health.