Research presented at AAIC found that people whose diets are full of junk food developed cognitive decline faster than those with healthier eating habits.
As we age, cognitive function declines. In some people, this process happens faster than others. Mounting research points to the idea that highly processed foods with lots of calories, salt, fat and added sugars — think: sugary sodas, grocery store birthday cake, fast food burgers and fries — may cause older adults’ cognitive abilities to decline faster.
At the Alzheimer’s Association International Conference this week, Natalia Gonçalves, PhD, from the University of São Paulo Medical School presented research that compared the cognitive health of older adults who frequently partook in foods that contain few to no unprocessed ingredients against the cognitive health of those who ate more than 80 percent healthy foods.
“The main takeaway is that diet is a modifiable lifestyle factor,” Gonçalves told Being Patient. “Therefore, we can choose to make better dietary choices in order to protect our brain health long term.”
The study tracked 10,775 people with an average age of 50 in Brazil for up to a decade, finding that people who ate lots of ultra-processed food — their diets were made up of 20 percent junk food at the start of the study — were more likely to experience declining decision making abilities and declining ability to learn, remember and focus on things overall as they aged. The research has now been submitted to scientific journals for peer review.
The findings support past evidence that highly processed junk food — i.e. higher cholesterol, more sugars — is associated with worse cognitive health. This preliminary work builds on other larger studies that have found older adults who ate more unhealthy foods had a smaller hippocampus, the region of the brain responsible for memory, which may lead to more memory difficulties or other cognitive challenges.
On the flip side, however, mounting evidence supports the idea that health diets — like the MIND or Mediterranean-style diet, which are low in processed foods, and high in vegetables, olive oil and omega 3s — improve brain health. Studies repeatedly imply that something about these diets helps to protect the brain from cognitive decline and Alzheimer’s.
In both cases, the science isn’t there yet to call these associations proven. Diet studies are often clouded with parallel lifestyle variables that are tough to control for. But Alzheimer’s Association Senior Director of Scientific Programs and Outreach Claire Sexton said while research continues, people have little to lose in taking up a healthier diet.
“There is growing evidence that what we eat can impact our brains as we age, and many studies suggest it is best to eat a heart-healthy diet low in processed foods, and high in whole, nutritional foods like vegetables and fruits,” Sexton said in a news release.
Future work is on the way to help clear up the complicated links between food and memory, uncovering why we might really be what we eat.