A new study found that mice with many of the pathologies of Alzheimer's disease showed fewer signs of the disease when given a protein-restricted diet supplemented with specific amino acids every other week for four months.
Mice at advanced stages of the disease were put on the new diet. They showed improved cognitive abilities over their non-dieting peers when their memory was tested using mazes.
In addition, fewer of their neurons contained abnormal levels of a damaged protein, called "tau," which accumulates in the brains of Alzheimer's patients.
Dietary protein is the major dietary regulator of a growth hormone known as IGF-1, which has been associated with aging and diseases in mice and several diseases in older adults.
USC Professor Valter Longo, the study's corresponding author, and his team found that a protein-restricted diet reduced levels of IGF-1 circulating through the body by 30 to 70 percent, and caused an eight-fold increase in a protein that blocks IGF-1's effects by binding to it.
IGF-1 helps the body grow during youth but is also associated with several diseases later in life in both mice and humans. Exploring dietary solutions to those diseases as opposed to generating pharmaceuticals to manipulate IGF-1 directly allows Longo's team to make strides that could help sufferers today or in the next few years.
Upcoming studies by Longo will attempt to determine whether humans respond similarly - while simultaneously examining the effects of dietary restrictions on cancer, diabetes and cardiac disease.
Longo worked with Pinchas Cohen, dean of the USC Davis School, as well as USC graduate students Edoardo Parrella, Tom Maxim, Lu Zhang, Junxiang Wan and Min Wei; Francesca Maialetti of the Istituto Superiore di Sanita in Rome; and Luigi Fontana of Washington University in St. Louis.
The results of their study were published online by Aging Cell last month. (ANI)