It was found that the diet started a life-or-death process for cells that is apparently crucial for repairing the body. "During the fasting-mimicking diet, cortisone is produced and that initiates a killing of autoimmune cells," said the study's lead author, Valter Longo, a professor who heads the USC Longevity Institute at the Davis School of Gerontology. "This process also leads to the production of new healthy cells."
Multiple sclerosis (MS) is a neurological disease that affects an estimated 2.3 million people worldwide, according to the National MS Society. Symptoms of the disease are highly variable between individuals and range from blurred vision to paralysis.
As a physiological readout, they observed increased levels of the hormone corticosterone, which controls metabolism. There was a reduction in the cytokines, which cause inflammation. Improvements in the white blood T cell counts were measured as well. Crucially, the researchers also found that the fasting-mimicking diet promoted a regeneration of the myelin sheath that was damaged by the autoimmunity.
"On the one hand, this fasting-mimicking diet kills bad immune cells," Longo said. "Then, after the mice return to the normal diet, the good immune cells but also the myelin-producing cells are generated, allowing a percentage of mice to reach a disease-free state."
The researchers were able to investigate the efficacy of the diet on people with multiple sclerosis through a pilot trial. Eighteen patients were put on the diet mimicking fasting for a seven day cycle followed by a Mediterranean diet for 6 months. In addition, for six months, 12 participants were on a normal diet, with 18 others were on a ketogenic diet. Those who got a fasting-mimicking, then Mediterranean diet cycle and those on a ketogenic diet reported improvements in their physical health, quality of life, and mental health.
"We are optimistic," Longo said. "What we don't want is patients trying to do this at home without involvement of their specialist or without understanding that larger trials are necessary to confirm that the diet, as a treatment, is effective against multiple sclerosis or other autoimmunities."
Sources: NIH, AAAS, Cell Reports