Seeing a grandparent die of Alzheimer’s disease had a strong effect on Dr. Gerald Calegan.

“I watched it in slow motion as I was growing up,” said Calegan, a neurologist at Baton Rouge’s The Neuromedical Center.

That personal connection led Calegan to delve into new research connecting diet to Alzheimer’s, a form of dementia that is the sixth highest cause of death in the U.S, according to the Alzheimer’s Association.

Over the past two years, he has read research questioning whether Americans could shrink their Alzheimer’s risk by eating certain foods and avoiding others. And, in a case of practicing what he preaches, Calegan has changed his own diet dramatically, eating more vegetables, cutting carbohydrates and sugary drinks and carefully choosing meats.

“I’m all in now,” he said. “I’m talking to patients now and starting to spread the word to patients because I’m confident that evidence is correct.”

Called the MIND diet by researchers, the regimen is a combination of two diets — the Mediterranean and the DASH — designed to fight cardiovascular disease. Researchers studied participants following the diet beginning in 1997 and found that those who followed the regimen rigorously had a 53 percent lower chance of developing Alzheimer’s disease. Participants who followed it “moderately well” shrank their risk by 35 percent.

The MIND diet, which stands for the cumbersome “Mediterranean-DASH Intervention for Neurodegenerative Delay,” encourages what researchers called “brain healthy food groups,” including:

Vegetables, especially green, leafy vegetables

Nuts

Blueberries and other berries

Fish and poultry

Olive oil

The MIND diet study also limits red meat, butter and margarine, cheese, sweets and fried foods.

Calegan approves of the study, published in March in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, but he does disagree on a few points. The journal article encourages consumption of whole grains, but Calegan said he believes any grains have a negative effect on blood sugar which eventually harms the brain.

Some doctors believe that Alzheimer’s disease is similar to diabetes, with some researchers even calling it “Type 3 diabetes,” Calegan said.

Inflammation in the body may be the culprit, he said.

The “Standard American Diet,” which Calegan calls by the acronym SAD, increases inflammation, while healthier foods fight it.

“Inflammation is at the root of every major medical problem that people have in our society,” Calegan said. “It all boils down to inflammation.”

The MIND diet eliminates inflammatory foods and encourages the consumption of anti-inflammatory berries, vegetables and oils. And exercise encourages brain-building hormones, Calegan said.

“We are finally starting to look at preventing (chronic diseases) instead of looking at expensive pills to try to mitigate them and it’s too late,” he said. “That’s what we’ve done thus far.”

Calegan knows that diet and exercise will not rid the world of Alzheimer’s disease, and it may not prevent all types of dementia. Many diseases that affect the brain have similar symptoms but completely different causes.

“What we call Alzheimer’s and what we call Parkinson’s, there are probably multiple ways to get there, based on the genes you have, based on the environmental exposures you’ve had to certain viruses, to certain foods, to certain drinks and certain lifestyles,” he said. “These all play a roll, and this is extremely complicated.”

But changing Americans’ habits will not be easy, he said, no matter what benefits they may reap.

“I do think we can reduce the risk of getting these things dramatically through proper diet and exercise,” Calegan said. “It will take a very large change in diet in this country.”