Fasting may improve recovery from spinal cord injury, according to a new rodent study.
Injured rats that were only fed on alternate days showed half the spinal cord damage compared with their normally fed counterparts after several months. The findings add to a growing body of evidence that calorie restriction can boost recovery from a variety of injuries.
Ward Plunet at the University of British Columbia in Vancouver, Canada, and colleagues created lesions in the spinal cords of a group of rats. Half of the animals were able to eat whenever they wanted, while the other 鈥渇asting鈥� half were fed only every other day.
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Over the course of these two months following the initial spinal injury, fasting rats showed slightly better improvement in their ability to complete a ladder-climbing task than their counterparts. Inspection of the rodents鈥� spinal cords then revealed that the lesions were 50% smaller in the fasting animals than the control animals.
Overzealous cells
Other studies have shown that a calorie restricted diet started several months before an injury such as stroke can protect neurons from dying. This is the first to show that calorie restriction can help after injury too, Plunet believes.
He suspects that fasting helps because it dampens the body鈥檚 immune system, causing fewer overzealous immune cells to reach the site of spinal injury. These cells sometimes block off the site of injury to such an extent that they prevent nerve regeneration.
Calorie restriction appears to make the cells in the spinal cord more sensitive to growth-promoting proteins, Plunet adds. Spinal cord biopsies from the animals in his study showed that the cells of fasting rats had more functional copies of a receptor that responds to a chemical that boosts nerve growth.
Profound changes
The study findings may seem counterintuitive, since people who are sick are often encouraged to eat more to help their body heal, Plunet admits.
鈥淭he findings challenge conventional medical protocols for severely ill, traumatised patients,鈥� says neurosurgeon Michael Fehlings at Toronto Western Research Institute, Canada.
However, he says, patients with spinal cord injury have undergone a major trauma to their body, which can result in profound metabolic changes that potentially leave them at risk of malnutrition, which fasting may exacerbate.
鈥淣onetheless, the current research is of major interest and suggests a novel therapeutic approach for spinal cord injury,鈥� Fehlings adds.
Plunet presented the findings at the annual Society for Neuroscience meeting in Atlanta, Georgia, last week.
