Data included genetic and health information and surveys covering what the participants ate and drank.
They were also tested on their fluid intelligence throughout the study period. These tests evaluated their ability to "think on the fly."
While genes put some people more at risk of developing progressive diseases like Alzheimer's, the scientists found that, overall, certain food choices can prevent cognitive decline.
This may have to do with the positive effect of calcium and vitamin B12. Lactopeptides, the scientists write, "may improve cognition in older adults" while probiotics may "attenuate depression."
"I was pleasantly surprised that our results suggest that responsibly eating cheese and drinking red wine daily are not just good for helping us cope with our current COVID-19 pandemic... "
The scientists note that, while eating red meat is often linked to worse health, "we discovered a unique beneficial relationship among some lamb consumers." This may have to do with the oleic acid in lamb — the same fatty acid found in olive oil.
Importantly, this is an observational study — meaning more research is needed to say exactly how and why these food factors affect the brain.
But other studies suggest dietary factors affect multiple brain processes, including the regulation of neurotransmitter pathways.