'Western' Diet & Alzheimer's-Like Effects in Mice
Whether findings might apply to humans remains to be seen
By Amy Norton
MONDAY, Feb. 24, 2014 (HealthDay News) -- Common compounds in the "Western" diet seem to promote Alzheimer's-linked brain deposits and memory problems in mice, researchers say.
Scientists found that when they added the compounds -- called advanced glycation end products (AGEs) -- to the lifelong diets of laboratory mice, the animals developed greater amounts of beta-amyloid in the brain. Beta-amyloid is the protein that makes up the brain "plaques" seen in people with Alzheimer's disease.
What's more, mice fed these compounds developed more problems with movement and memory as they aged compared to mice that spent their lives dining on chow that produced low levels of these chemicals.
AGEs are naturally present in small amounts in the human body, said senior researcher Dr. Helen Vlassara, of the Mount Sinai School of Medicine in New York City. But you also ingest the compounds through food -- particularly animal products prepared at a high heat.
That includes fried, grilled or broiled meats, and dairy products that are pasteurized or sterilized.
"We ingest these toxins in huge amounts over a lifetime," Vlassara said.
The problem with that, she explained, is that accumulating AGEs can promote chronic inflammation in the body. And that type of persistent, low-level inflammation is implicated in many disease processes, including Alzheimer's.
The new findings, reported Feb. 24 in the Proceedings of the National Academy of Sciences, suggest that a diet high in these compounds is unhealthy for mouse brains.
But what about people? To get an idea, Vlassara's team followed 93 adults aged 60 and older who gave blood samples and completed a standard questionnaire doctors use to screen for dementia.
The investigators found that people with higher blood levels of a particular AGE tended to show a bigger dip in mental acuity over nine months.
However, another Alzheimer's researcher said much more work is needed to clarify how these compounds might affect the human brain.
"We need larger, well-controlled studies to identify a strict correlation between dietary AGEs and cognitive [mental] decline," said Dr. Jeremy Koppel, a geriatric psychiatrist and scientist at the Feinstein Institute for Medical Research in Manhasset, N.Y.
"Well-controlled" means that researchers would have to account for many other factors in people's mental function -- such as education, overall health and lifestyle habits. Koppel said studies should also use "more elaborate" tests of memory and other mental abilities, and not only the short screening tool used in this study.
For now, he said, "The take-away is that a diet enriched in these compounds seems to do bad things in mice."
Vlassara agreed that more human studies are needed. But she said people don't have to wait to make dietary changes -- especially since cutting down on foods high in these compounds, and eating more plant-based foods, generally are considered healthy moves.