Too much of an amino acid typically found in red meats, fish, beans, eggs, garlic, lentils, onions, yogurt and seeds can increase the risk of Alzheimer's disease, says a new study.
According to Temple researchers, a diet rich in amino acid methionine can up a person's chances of developing Alzheimer's.
The researchers published their findings, titled "Diet-induced hyperhomocysteinemia increases Amyloid-_ formation and deposition in a mouse model of Alzheimer's disease," in the journal Current Alzheimer Research.
"When methionine reaches too high a level, our body tries to protect itself by transforming it into a particular amino acid called homocysteine," said lead researcher Domenico Praticr, an associate professor of pharmacology in the School of Medicine.
"The data from previous studies show - even in humans - when the level of homocysteine in the blood is high, there is a higher risk of developing dementia. We hypothesized that high levels of homocysteine in an animal model of Alzheimer's would accelerate the disease," the expert added.
A brain sample taken from mice used in the study shows dark spots consistent with amyloid plaque, indicative of the progression of Alzheimer's disease. Mice fed diets rich in methionine had an increased level of homocysteine and up to 40 percent more amyloid plaque in their brains.
Still, Praticr emphasized, methionine is an essential amino acid for the human body and "stopping one's intake of methionine won't prevent Alzheimer's. But people who have a diet high in red meat, for instance, could be more at risk because they are more likely to develop this high level of circulating homocysteine," he said.