Nerve injuries are hard to recover from. Skin heals in days, and even bone knits back together in weeks. Nerve tissue regrows slowly, and in the spinal cord it may barely regrow at all. Anyone who has watched a friend or family member work through months of rehab after a back or neck injury knows how slow and uncertain that road can feel. That is why researchers keep looking for anything that might help protect nerve tissue after an injury, including diet.
In 2021, a team of researchers reviewed the research on two diet strategies, the ketogenic diet and intermittent fasting, after traumatic injuries to the spinal cord and peripheral nerves. Their review was published in PLOS ONE. Below, we walk through what they did, what they found, what the individual studies looked like, and, just as important, what the review cannot tell us.
Why we cover this research
Audacious was founded on the science of ketones and the nervous system. When a careful review summarizes a whole area of research, we think our readers deserve a clear, honest summary, including the parts that are still uncertain. We would rather you understand the limits of the evidence than come away with false hope.
A quick primer: ketosis and fasting
A ketogenic diet is very low in carbohydrates and high in fat. When carbohydrates are scarce, the liver turns fat into ketone bodies, mainly beta-hydroxybutyrate (BHB), which the brain, spinal cord and other tissues can use for fuel. This state is called ketosis.
Intermittent fasting means cycling between eating and not eating. In the animal studies in this review, it usually meant every-other-day fasting: food one day, no food the next. Fasting also raises ketone levels, which is one reason researchers group these two strategies together.
Why would ketones matter after a nerve injury? Injured nerve tissue often has trouble using glucose (blood sugar) efficiently, and repair is energy-hungry work. Researchers have proposed that ketones may offer an alternative fuel and may also calm inflammation and oxidative stress, a kind of chemical wear and tear on cells. These are hypotheses, and they are exactly what studies like these try to test.
What is a systematic review?
A systematic review follows a fixed, published method to find every study on a question, decide which ones qualify, and summarize them. It is designed to reduce cherry-picking. Think of it as the difference between asking one friend for a restaurant recommendation and reading every review on the site using the same checklist. It is not perfect, because it can only be as good as the studies it includes, but it gives a fairer picture than any single study.
What the researchers did
- They searched the medical literature (the MEDLINE database) from 1950 to 2020 and screened 1,890 articles.
- 11 studies met their criteria, all in animals (mostly rats, two in mice).
- 7 studies tested a ketogenic diet; 4 tested intermittent fasting, all using every-other-day fasting.
- 8 looked only at the spinal cord; 2 looked only at peripheral nerves, the nerves outside the brain and spinal cord; and one mouse study looked at both.
Studies of the brain and the optic nerve were left out, so this review speaks only to the spinal cord and peripheral nerves.
What they found
In most of the included studies, the diet groups showed benefits, either in the tissue under the microscope (such as more preserved nerve tissue) or in function (such as better use of a limb).
For example, one included rat study gave a ketogenic diet plus ketone salts right after a spinal cord injury and reported better forelimb recovery. Not every study was positive: one mouse study found no effect on recovery of movement and sensation.
The authors concluded that intermittent fasting and the ketogenic diet "may promote neuroprotection" after these injuries. Neuroprotection means helping nerve cells survive the damage that follows an injury.
A closer look at three of the included studies
Summaries can hide the details, so here are three of the individual studies the review included. Together they show both the promise and the mixed picture.
Ketogenic diet after a neck-level spinal cord injury in rats (2013)
Researchers in Vancouver gave rats a partial injury to the spinal cord at neck level. Starting 4 hours after the injury, one group ate a ketogenic diet and the other ate a standard diet. The ketogenic diet continued for 12 weeks, and the team tracked forelimb function for 14 weeks. The ketogenic group used the affected paw more, reached and grasped better, and had smaller injured areas with more preserved tissue. When the researchers blocked the transporters that carry ketones into cells, the protective effect disappeared, which suggests the ketones themselves played a role. View the abstract
Every-other-day fasting after spinal cord injury in rats (2008)
The same research group tested every-other-day fasting, started after a neck-level spinal cord injury in rats. The fasting rats did not lose weight overall, walked better, and performed better on a ladder-crossing task. Their injured areas were less than half the size of those in the control rats, and their blood BHB rose two- to threefold on fasting days. View the abstract
A ketogenic diet that did not help, in mice (2020)
Not every result was positive, and that matters. In a mouse study, animals ate a strict ketogenic diet for 7 days before and 28 days after either a mid-back spinal cord injury or an injury to leg nerves. Their blood ketones rose, but the diet gave no benefit for walking, coordination or touch sensitivity over those 28 days. The authors suggested the effects of a ketogenic diet may depend on the type and location of the injury. View the abstract
What this study does not show
- All 11 studies were in animals. The review included no human studies.
- The studies used different animals, diets and timing, so the authors could not combine them into one overall number.
- Only one database was searched, so some relevant studies may have been missed. Several studies also came from the same research groups, so they are not fully independent.
- "May promote neuroprotection" is a careful phrase. It means the idea deserves more research, especially in people.
If you are living with a nerve or spinal cord injury, this review is not a treatment plan. It is a look at where the science is today.
What about people?
Human research is just beginning. In a small 2018 pilot trial, 7 adults with a new spinal cord injury were randomly assigned to a ketogenic diet (4 people) or a standard diet (3 people) while in acute care and rehab. The main goal was to see whether the diet was safe and practical in a hospital setting, and it appeared to be. The ketogenic group had higher arm motor scores at discharge, but with only 7 people the authors called the results preliminary and said larger studies are needed. View the abstract
That is where human evidence stands: a promising feasibility signal, not proof of benefit.
Where this fits in the bigger picture
A larger meta-analysis of 49 studies on ketosis after acute brain and spinal cord injury found a similar pattern in animals. In that analysis, ketosis was linked to lower mortality, less neuronal damage and less loss of function in rodents. For a look at what happens inside injured neurons, see Dr. Ari's 2024 lab study on ketone salts, in which rat neurons in a dish given BHB moved into a scratched "injury" gap more than untreated cells did. For practical, everyday context, read Nerve Damage Recovery: What Helps, and What Ketone Research Is Exploring.
Practical takeaways if you are following this research
- Bring it to your care team. If this research interests you, share the paper with your doctor or rehab team rather than changing your diet on your own. Our list of questions to ask your doctor can help.
- Do not fast after an injury without supervision. Recovery often raises your need for calories and protein, and fasting can make that harder to meet.
- Watch for human trials. The most useful next step for this field is well-designed trials in people. Registries like ClinicalTrials.gov list studies that may be recruiting.
- Keep the foundations first. Medical care, rehab, sleep and good nutrition remain the backbone of recovery.
Common questions
Does this review prove a ketogenic diet helps spinal cord injuries?
No. It shows that most animal studies found some benefit, which makes the idea worth studying in people. No human studies were included, and the authors themselves used cautious language.
Is intermittent fasting or a ketogenic diet better after a nerve injury?
The review could not answer that. The studies differed too much in animals, diets and timing to compare the two approaches directly.
Why does timing matter so much?
Much of the damage after a spinal cord injury happens in the hours and days after the first impact, through swelling, inflammation and energy failure. Many of the positive animal studies started the diet soon after the injury, and it is not known whether starting later would have the same effect.
Can I get the same effect from a ketone supplement?
That has not been tested in people with nerve injuries. One included rat study combined a ketogenic diet with ketone salts, but a diet and a supplement work differently. Here is how they differ.
Read the study
Sayadi JJ, Sayadi L, Satteson E, Chopan M. Nerve injury and repair in a ketogenic milieu: a systematic review of traumatic injuries to the spinal cord and peripheral nervous tissue. PLOS ONE. 2021;16(1):e0244244. doi:10.1371/journal.pone.0244244. Read the full open-access paper.
The bottom line
This systematic review found that, in most animal studies, a ketogenic diet or every-other-day fasting after spinal cord or peripheral nerve injury was linked to better tissue preservation or function. The evidence is entirely from animals, the studies varied widely, and at least one found no benefit. It is an encouraging direction for research, not a treatment for people.
Curious about ketones?
If you are exploring a ketogenic lifestyle, KETOSTART is designed to help you get into ketosis and maintain it, with 6 g of BHB and electrolytes per serving.
References
- Sayadi JJ, Sayadi L, Satteson E, Chopan M. Nerve injury and repair in a ketogenic milieu: a systematic review of traumatic injuries to the spinal cord and peripheral nervous tissue. PLOS ONE. 2021;16(1):e0244244. PubMed
- Streijger F, Plunet WT, Lee JH, et al. Ketogenic diet improves forelimb motor function after spinal cord injury in rodents. PLOS ONE. 2013;8(11):e78765. PubMed
- Plunet WT, Streijger F, Lam CK, Lee JH, Liu J, Tetzlaff W. Dietary restriction started after spinal cord injury improves functional recovery. Experimental Neurology. 2008;213(1):28-35. PubMed
- Mayr KA, Kwok CHT, Eaton SEA, Baker GB, Whelan PJ. The effects of a ketogenic diet on sensorimotor function in a thoracolumbar mouse spinal cord injury model. eNeuro. 2020;7(4):ENEURO.0178-20.2020. PubMed
- Yarar-Fisher C, Kulkarni A, Li J, et al. Evaluation of a ketogenic diet for improvement of neurological recovery in individuals with acute spinal cord injury: a pilot, randomized safety and feasibility trial. Spinal Cord Series and Cases. 2018;4:88. PubMed
- Gambardella I, Ascione R, D'Agostino DP, Ari C, et al. Neuroprotection of ketosis in acute injury of the mammalian central nervous system: a meta-analysis. Journal of Neurochemistry. 2021;158(2):105-118. PubMed
- Ari C, D'Agostino DP, Cha BJ. Neuroregeneration improved by sodium-D,L-beta-hydroxybutyrate in primary neuronal cultures. Pharmaceuticals (Basel). 2024;17(9):1160. PubMed
Disclosure: Dr. Csilla Ari, a co-author of references 6 and 7, is the founder of Audacious.
This article summarizes published research for educational purposes. It is not medical advice, and these statements have not been evaluated by the FDA. Our products are not intended to diagnose, treat, cure or prevent any disease. Talk to your doctor before starting a ketogenic diet, fasting or supplements, especially after an injury.