Study Links Saturated Fat To Cognitive Decline
May 21, 2012

Study Links Saturated Fat To Cognitive Decline

Saturated fats, already decried by health experts because past studies have linked them to cardiovascular and other diseases, could actually impair how well a person's brain functions, according to a new study published Friday in the Annals of Neurology.

In the paper, researchers from Brigham and Women´s Hospital in Boston analyzed the diets of more than 6,000 women aged 65 or older over the course of four years, Brian Fung, associate editor at The Atlantic, wrote late last week.

During that period, they found that those women who consumed greater amounts of saturated fat, which is found in red meat, butter and other full-fat dairy products, scored worse on cognitive function tests than those who consumed primarily the polyunsaturated fats found in corn and vegetable oils, Fung and Deborah Kotz of the Boston Globe added.

"When looking at changes in cognitive function, what we found is that the total amount of fat intake did not really matter, but the type of fat did," study author Dr. Oliva Okereke, a psychiatrist and epidemiologist at the hospital, told Telegraph Medical Correspondent Stephen Adams on Sunday. "Substituting in the good fat in place of the bad fat is a fairly simple dietary modification that could help prevent decline in memory."

“In general, when it comes to dietary fat, the message has been pretty consistent over time that those dietary fats that are beneficial for cardiovascular health might similarly be beneficial for brain health,” she added in a separate interview with Kotz. “Our analysis suggests if you substitute out 5 percent of your saturated fat calories with 5 percent monounsaturated fats, you could have a 50 percent lower risk [of memory and cognitive decay]."

According to the Boston Globe, the study found that women who had a higher intake of saturated fat had brains that appeared to be an average of five or six years older than their biological age, while those who consumed more monounsaturated fat had brains that were reportedly six or seven years younger.

The total fat consumption did not appear to have an effect on brain aging, and neither polyunsaturated fats nor trans fats were found to be linked to cognitive decline in this study, the newspaper added.

"Like most nutrition studies, this one can´t prove that dietary fat has a direct effect on brain function because it didn´t randomly assign women one diet or the other to follow," Kotz pointed out in her May 18 report. "While the researchers accounted for differences in body weight, smoking, alcohol use, and certain health conditions such as diabetes and hypertension, they couldn´t look at all potential differences between those who ate high amounts of saturated fats compared with those who ate more monounsaturated fats."

"For example, the study didn´t look at total fruit or vegetable consumption," she added. "That said, enough evidence has accumulated from a host of dietary studies to suggest that it´s wise to limit your intake of saturated fat, opting instead for healthier monounsaturated fats."