The more calories the adults took in, the higher their risk for mild cognitive impairment (MCI), which is the medical term for mild memory loss. While not serious enough to seriously interfere in their daily lives, people with MCI may have problems remembering recent events and/or new information, as well as have issues with other brain functions. People with MCI are at greater risk for developing dementia, but not all do.
The study involved more than 1,200 people between the ages of 70 and 89, including 163 who had signs of MCI. Participants described their diet during the preceding year in a food questionnaire.
One-third ate between 600 and 1,526 calories per day, one-third ate between 1,526 and 2,143, and one-third ate between 2,143 and 6,000 calories per day, the study shows. The results took into account other factors such as age, sex, education level, history of stroke, and depression.
Risk Increases With Calories
Those who took in the highest number of calories per day had double the risk for MCI.
"This fits into what we know about midlife risk factors for Alzheimer's disease," says Sam Gandy, MD, PhD, in an email. He is the associate director of the Mount Sinai Alzheimer's Disease Research Center in New York. "We know that obesity increases risk for Alzheimer's, and we know that caloric restriction decreases risk for Alzheimer's, so the overeating story fits well."
David Loewenstein, PhD, agrees. "More and more research has shown that anything that is good for the heart is good for the brain, and when people overeat, there are complications including risk for diabetes, stroke, and memory problems." He is a professor of psychiatry and behavioral sciences at the University of Miami Miller School of Medicine.
Eat Less, Exercise More to Protect Brain
His advice? Try to rein in the number of calories you eat, and exercise on a regular basis. "If you cut calories and replace empty calories with nutritious foods, your risk for brain disease and heart disease are reduced significantly."
Marc L. Gordon, MD, says the new study can’t tell us whether eating too much causes memory problems. It may be that memory problems cause us to eat too much. He is the chief of neurology at Zucker Hillside Hospital in Glen Oaks, N.Y., and an Alzheimer’s researcher at The Feinstein Institute for Medical Research in Manhasset, N.Y. “To say that we should advocate calorie restriction is not warranted. More needs to be done to try and factor in the direction of this association.”
Christine Tangney, PhD, is an associate professor of clinical nutrition at Rush University Medical Center in Chicago. “People in their 70s and 80s should not be consuming more than 2,100 calories per day,” she says. “Anyone consuming that many calories is at risk for many diseases including poor cognition and obesity.”
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.
About the Author