Do you like your steak rare or well done? The answer could influence how mentally sharp you stay as you age, new research suggests. Scientists have found that compounds known as glycotoxins, which form as we brown (or blacken) certain foods, may increase the risk of age-related dementia.
Publishing in the Proceedings of the National Academy of Sciences last year, researchers from the Icahn School of Medicine at Mount Sinai in the US linked diets high in glycotoxins to age-related dementia and obesity and diabetes in both humans and mice.
The researchers found that mice that were raised on a diet high in glycotoxins (specifically a type called advanced glycation end products, or AGEs), were more likely to develop dementia-like cognitive and movement problems as they aged than mice fed a low-glycotoxin diet. The mice fed a lot of AGEs also had increased amounts of amyloid beta proteins in their brains, which are the sticky proteins that form plaque in the brains of people with Alzheimer's disease.
The team then monitored the amount of AGEs in the blood of 93 New Yorkers aged over 60 for a period of nine months. During this time they also asked the participants how often they were eating glycotoxins and monitored their cognitive function and their insulin sensitivity - which is a major marker for the risk of metabolic syndromes such as diabetes and obesity.
They found that the participants who had more AGEs in their blood over the course of the study experienced more cognitive decline than their peers, as well as reduced insulin sensitivity.
The diets of these participants weren’t monitored in the lab, so we don’t know exactly how many glycotoxins they were eating, but the researchers believe there's now enough evidence to further investigate whether eating rarer meat could offer a simple way to reduce our risk of dementia and metabolic syndromes as we age.
But although the results are interesting, there's still a lot more research to be done. "These studies are only preliminary and more evidence is required in the form of large scale epidemiological studies before we start recommending how to best cook our food," Michael Woodward, a dementia researcher from Austin Health in Australia, told Dementia News.
"However, this study further adds to a growing body of evidence that suggests what you eat - for example highly fatty, fried and processed foods can be linked to diseases such as dementia, diabetes and cardiovascular disease," he added.