February 15, 2013
Low Protein Diet Slows Alzheimer’s, Improves Brain Function In Lab Mice
Connie K. Ho for redOrbit.com — Your Universe Online
A study from the University of Southern California (USC) recently found that a normal, low-protein diet could slow signs of Alzheimer´s and boost memory in mice. The Alzheimer´s Association defines the disease as a form of dementia related to difficulties with behavior, memory and thinking.
In the study, mice with advanced stages of Alzheimer´s disease were put on a new diet. They were given specific amino acids every other week along with a protein-restricted diet over a four-month period. The scientists then tested the memory of the mice using mazes, and their results showed that the mice with the low-protein diet had improved cognitive function compared to the mice in the control group. They also discovered that the mice that consumed less protein had fewer abnormal levels of tau, a harmful protein found in patients diagnosed with Alzheimer´s.
In addition, the researchers studied the correlation between IGF-1, a growth hormone that is regulated by dietary protein, and Alhzeimer´s. IGF-1 is known to play a role in the development of the body during youth but has also been connected to several diseases that occur later in life. The USC team of researchers found that a protein-restricted diet lowered the levels of IGF-1 in the mice by 30 to 70 percent.
"We had previously shown that humans deficient in Growth Hormone receptor and IGF-I displayed reduced incidence of cancer and diabetes. Although the new study is in mice, it raises the possibility that low protein intake and low IGF-I may also protect from age-dependent neurodegeneration," explained Valter Longo, a USC Professor who directs the Longevity Institute of the USC Davis School of Gerontology, in a prepared statement.
"Alzheimer's Disease and other forms of neurodegeneration are a major burden on society, and it is a rising priority for this nation to develop new approaches for preventing and treating these conditions, since the frequencies of these disorders will be rising as the population ages over the next several decades," said Pinchas Cohen, dean of USC School of Gerontology. "New strategies to address this, particularly non-invasive, non-pharmacological approaches such as tested in Dr. Longo's study are particularly exciting."
The researchers believe that it is important to look into dietary solutions to the diseases instead of producing pharmaceuticals that can impact IGF-1 directly. "We always try to do things for people who have the problem now," continued Longo in a statement. "Developing a drug can take 15 years of trials and a billion dollars.”
The researchers says that it is important for doctors or registered dieticians to monitor the health of elderly patients who do decide to engage in a protein-restricted diet in order to ensure that they do not become deficit in amino acids, lose extra weight or develop other side effects.
"Although only clinical trials can determine whether the protein-restricted diet is effective and safe in humans with cognitive impairment, a doctor could read this study today and, if his or her patient did not have any other viable options, could consider introducing the protein restriction cycles in the treatment — understanding that effective interventions in mice may not translate into effective human therapies," remarked Longo in the statement.
Research into Alzheimer´s treatment has gained enormous traction in the last few years as public awareness of the devastating disease continues to grow. Last year President Barack Obama´s administration pledged to boost efforts to fight Alzheimer´s disease, including increasing federal funds available for Alzheimer´s research. They also placed an emphasis on improving caregiver support, public health education and data infrastructure.
“We can´t wait to act; reducing the burden of Alzheimer´s disease on patients and their families is an urgent national priority,” said US Health and Human Services Secretary Kathleen Sebelius in a prepared statement.
The results of the study were published in the online edition of the journal Aging Cell last month.