In other words, the brain appeared to function differently depending on diet, but it did not look different. So what might be going on?
According to Lona Sandon, a registered dietician nutritionist and professor of nutrition at the University of Texas Southwestern in Dallas, “We could hypothesize that it has something to do with inflammation for one, as well as with other nutrients like magnesium or folate that are found in the leafy greens.”
Sandon also acknowledged the important role healthy fats, such as monounsaturated and polyunsaturated fats, appear to play in keeping the brain and body functioning at their best. These healthy fats, which are found in high amounts in the Mediterranean diet, help reduce inflammation in the body.
“This helps to protect blood vessels, and it’s not just blood vessels that lead to the heart, but blood vessels that lead to the brain and everywhere else in the body,” said Sandon, who wasn’t involved in the new research.
Also at play may be various antioxidants, also found in abundance in the Mediterranean diet.
On the other hand, less healthy diets — dominated by processed foods — could have the opposite effect, the Scottish researchers warned. That’s because these types of diets tend to be high in red meat, potatoes, and sugary and fried foods.
Of these, Sandon noted, red meat appears to be particularly unhealthy for the brain, probably because of red meat’s high level of saturated fat. She added that processed foods are also packed with excessive salt, sugar and other components that can make them both cheap and addictive.
But if you’ve eaten an unhealthy diet most of your life, is it too late to change to a Mediterranean (or any other healthy) diet in your 60s or even 70s? Could the brain still benefit?
The answer is that it’s never too late, the experts said.
“Cognitive decline is a risk factor for dementia, for which there is currently no cure,” Corley said. “Therefore, strategies to prevent or delay cognitive decline, by changes in modifiable lifestyle factors such as diet, are important in terms of public health.”