Amino Acid Linked to Alzheimers

PHILADELPHIAA diet rich in methionine, an amino acid found in red meats, fish, beans, eggs, garlic, lentils, onions, yogurt and seeds, can possibly increase the risk of developing Alzheimers disease, according to a study by Temple researchers (Curr Alzheimer Res. PMID: 19939226).

Researchers used a seven-month old mouse model of the disease. They fed one group an eight-month diet of regular food and another group a diet high in methionine. The mice were then tested at 15 months of agethe equivalent of a 70-year-old human. They found that mice with the normal diet had normal homocysteine levels, but the mice with the high methionine diet had significantly increased levels of homocysteine. When methionine reaches too high a level, the human body tries to protect itself by transforming it into a particular amino acid called homocysteine. Previous studies have shown high levels of homocysteine increase the chance of developing dementia.

The group with the high methionine diet also had up to 40-percent more amyloid plaque in their brains, which is a measurement of how much Alzheimer s disease has developed. The researchers also found the capacity to learn a new task diminished in the group with the diet high in methionine.

The study was funded by grants from the National Institute of Health and the Alzheimers Association, in addition to support from Pennsylvania Commonwealth through the Fox Chase Cancer Center.