Eating leafy greens helps preserve intelligence over the lifetime, research finds.
Leafy greens and other foods contain lutein, a plant pigment that protects the brain from aging.
People with more lutein in their blood did better on intelligence tests, the study found.
Lutein collects in the cell membranes of the brain, playing a ‘neuroprotective’ role.
Foods that contain high levels of lutein include leafy green vegetables like kale and spinach as well as broccoli, cauliflower and cabbage.
Dr Marta Zamroziewicz, the study’s first author, said:
“Previous studies have found that a person’s lutein status is linked to cognitive performance across the lifespan.
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.”
For the study, 122 people aged 65 to 75 took tests of crystallised intelligence.
Crystallised intelligence is akin to general knowledge.
Blood tests revealed that people with higher levels of lutein did better on these tests.
Scans also revealed that lutein helped preserve critical areas of the brain.
Professor Aron Barbey, study co-author, said:
“Our analyses revealed that gray-matter volume of the parahippocampal cortex on the right side of the brain accounts for the relationship between lutein and crystallized intelligence.
This offers the first clue as to which brain regions specifically play a role in the preservation of crystallized intelligence, and how factors such as diet may contribute to that relationship.”
Dr Zamroziewicz said:
“Our findings do not demonstrate causality.
We did find that lutein is linked to crystallized intelligence through the parahippocampal cortex.”
Professor Barbey said:
“We can only hypothesize at this point how lutein in the diet affects brain structure.
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.”
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The study was published in the journal Frontiers in Aging Neuroscience (Zamroziewicz et al., 2016).