What Do You Think About The Fasting Mimicking Diet For People With MS?

Question:
​What do you think about the Fasting Mimicking Diet?

Answer:
The fasting mimicking diet (FMD) is an interesting addition to the paradigm of the “anti-inflammatory diet”.  By using a low calorie and low protein diet for brief periods, researches hypothesize that this MAY help the MS disease process.   Earlier this month, Dr. Longo (from USC) published a paper on this topic where they first studied the effect of FMD on mice that have been given a condition called EAE (which is the closest disease state that appears like MS in mice).  They gave this diet to mice for 3 days every week and found that when compared to a control group of mice (i.e., a group that had a regular mouse diet), that the FMD mice had less disability and even 20% of the mice had complete reversal of symptoms.  They also found that the FMD mice had an increase of T-regulatory cells (which is a good thing), and a reduction of angry/inflammatory Th1 and Th17 cells (also a good thing).  Interestingly, they also found that the FMD mice appeared to have improved remyelination with a promotion of oligodendrocyte precursor cells (the cells that make myelin).

So, it appears that the FMD is helpful in mice that are given a disease that looks like MS, which is very interesting.  The next question is, will it help humans with ACTUAL MS?  The even more basic question is… is the FMD safe for humans to submit themselves to?

Dr. Longo’s recent paper reported a feasibility study where 60 patients with MS were randomized to a “control”, “Ketogenic”, or “FMD” diet.  The ketogenic diet is a high fat diet used to help treat children with difficult to control seizures, and served as a reasonable comparator arm in this feasibility study.  The patients were assigned these diets for 6 months and followed by the researchers.  What they found was the the diets appear safe; however, only 60% of the patients in the control diet group complied with the protocol whereas 100% did in the FMD group.  About 78% of the FMD group reported some adverse event (usually an airway infection, i.e., the cold) or a UTI.  The researchers also noted that the white blood cell count of patients being treated with FMD had a reduction of white blood cells by ~20% which then rebounded to normal after switching off the FMD diet.  Interestingly, they also saw a “mild reduction in” disability among patients using the FMD diet.

This is very interesting.  Dr. Longo and his colleagues have shown that mice with a disease like MS are benefitted by the FMD and that humans with MS appear to tolerate a FMD diet.  There is preliminary data suggesting the FMD may be beneficial in what matters for MS patients (namely stability/improvement of disability).  

So, what needs to happen now?

The short answer is:  1) this data needs to be replicated so we can have confidence that these preliminary findings are real, and 2) we need more data on the impact of FMD on actual patient with MS which would include not only neurologic exam findings, but blood monitoring (to determine what actually happens in the body when exposed to the FMD) and to assess FMD’s impact on inflammation in the brain and spinal cord in MS patients (i.e., through the use of MRI).

What is not clear based on the paper is the exact make-up of the diet used in the protocol.  Undoubtedly, the researchers are planning the next phase of testing.

For those interested in participating in research such as this, I would suggest you keep your eye on www.clinicaltrials.gov and search for ‘fast mimicking diet’.  At the time of this blog post, I do not see any actively recruiting trials, but I suspect that will change in the future.  On the .gov website you will find contact information for future studies as well as proposed locations for the research.  I would also suggest you discuss with your doctors about the safety of such a diet since everyone is different and other diagnoses for a given individual may make such a diet more risky.

Hope this helps,

A. Scott Nielsen MD MMSc
Neurologist and MS Specialist at Kaiser Permanente