Your diet could play a role in your long-term neurological health, according to researchers at Harvard University and the Massachusetts Institute of Technology

Researchers at Harvard and MIT are giving us a new look inside the human brain and its connection to what we eat.

They scientists found that red meats may have a negative impact on cognitive skills.

"I'm not surprised, because there are many studies that show there's a connection between what you eat and your health," said nutritionist Sue-Ellen Anderson-Hayes. "We are what we eat, for sure."

The researchers say they've found eating a lot of red meat -- especially in processed forms like hot dogs, sausage and bacon -- increases the risk of dementia by 13%.

The study included thousands of older people and their dietary habits over decades.

"When we think about processed foods, particularly red meats, they are more inflammatory. It causes our arteries to build up in plaque," said Anderson-Hayes. "Your risk for heart disease, for stroke, for even dementia, goes up."

Published in the journal "Neurology," the study is not all bad news. It found eating unprocessed red meats, like burgers and steak, isn't as cognitively debilitating as the processed ones. Even more encouraging, it found replacing processed meats with legumes, fish and nuts may reduce the risk of dementia by nearly 20%.

"It's going to prevent those plaque formations, and it's going to increase better blood flow to the entire body, better blood flow to the heart, equals better blood flow to the brain," Anderson-Hayes said.

And while food is certainly one factor, researchers say we need large, long-term studies to understand the causes of dementia and cognitive decline more fully.