LOS ANGELES -- You may be what you eat, but new research finds your diet and lifestyle may affect how you think.
A new study confirms a link between body fat and brain volume. And who this affects the most may surprise you.
Susan Savett, 66, has made a choice to eat better and get more fit. The reason is not just about her body, but her brain.
"My mother had Alzheimer's, and she had a weight issue as well," said Savett.
Easy tasks and recalling things started to become a challenge.
"I couldn't remember the beginning of sentences. I couldn't remember what I did in the morning," she said.
An international study including researchers from Providence Saint John's Health Center may explain what was happening to Savett.
"There's a relationship between body fat and reduced brain volumes," said Dr. Cyrus Raji with Washington University in St. Louis.
"It turns out when you have a lot of fat cells, fat tissues that are overactive and inflamed, they're sending these cytokine signals to the brain which are telling the brain to actually downsize," said Dr. David Merrill with Providence St. John's Health Center.
When brain volume goes down it increases the risk for dementia later in life. Researchers used MRI scans to examine the body fat and brain volume of 10,000 participants. Surprisingly, the effect was most pronounced in those ages 20-39 compared to older participants.
"That's important because that means that the changes that we're seeing in the brain related to body fat aren't just a product of normal aging," Raji said.
The study also found that women experienced a higher correlation between increased abdominal fat and lower brain volume compared to men. Researchers said differences in hormone levels may be the reason.
"What we want to explore is whether or not changes in hormones with aging could influence this result," Raji said.
Can you reverse brain shrinkage? Working with Dr. Merrill, Savett has been able to slow her cognitive decline through lifestyle changes. She said she's experiencing a noticeable change.
"I like to think of it as a 'feeding-the-brain diet.' And now I'm feeling even sharper than I ever was," Savett said.
Merrill prescribes 30 minutes of moderate daily activity, eating a nutritious diet of 2,000 calories or less a day.
And, he said, ask yourself this: "Are the foods you're choosing nourishing both your body and your brain," he said.
Savett said the choice is yours.
"You have the opportunity to make choices every day. I'm living proof of how I've reversed my cognition," she said.