p> A diet rich in methionine, an amino acid typically found in red meats, fish, beans, eggs, garlic, lentils, onions, yogurt and seeds, can possibly increase the risk of developing Alzheimer’s disease, according to a study by Temple researchers.

The scientists fed one group of mice an eight-month diet of regular food and another group a diet high in methionine. The mice were then tested at 15 months of age — the equivalent of a 70-year-old human. The researchers examined capacity to learn a new task and found it diminished in the group with the diet high in methionine.
The study found that mice fed diets rich in methionine had an increased level of homocysteine and up to 40 percent more amyloid plaque in their brains – the standard measurement to see how far Alzheimer’s disease develops.

Methionine is an essential amino acid for the human body but when methionine reaches too high a level, our bodies try to protect themselves by transforming it into a particular amino acid called homocysteine.

Data from previous studies has shown that when the level of homocysteine in the blood is high, there is a higher risk of developing dementia.

“Stopping the intake of methionine will not prevent Alzheimer’s,” said lead researcher Domenico Praticò, “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.”

The researchers published their findings in the journal Current Alzheimer Research.