High daily doses of vitamin D may improve the quality of life for patients diagnosed with Amyotrophic Lateral Sclerosis (ALS) or Lou Gehrig’s disease, a study at York University has found.
Using an animal model, the study’s researchers found that the motor performance and muscle endurance of mice with ALS improved when they were given higher than normal doses of vitamin D.
“We are the only group in Canada that is looking at the connection between dietary interventions and the effects on the ALS model,” says York kinesiology Professor Mazen Hamadeh (left) of the University’s Muscle Health Research Centre in the Faculty of Health. Hamadeh supervised the research led by York master of science degree students Jesse Solomon and Alexandro Gianforcaro in the School of Kinesiology & Health Science.
The researchers conducted three different studies looking at different amounts of vitamin D. The first looked at the effects of 10 times the adequate intake of vitamin D on the ALS animal model – the equivalent of 8,000 IU/day in humans. Results showed an improvement in both motor performance and endurance, but no change to disease outcomes, such as onset, progression or lifespan.
“We followed up with another study because we thought we didn’t give high enough amounts of vitamin D,” says Hamadeh. In the second study, the amount of vitamin D was increased to 50 times the suggested adequate intake amount or the equivalent of 40,000 IU per day in humans. Again, there was definite improvement in functional outcomes, but not in disease outcomes, confirming the findings of the first study, he says.
The researchers then thought that perhaps the recommended adequate intake amount of vitamin D was set too high and there was already an overabundance of vitamin D being administered. That led to a third study where only one fortieth of the recommended adequate intake amount was administered using the animal model, which induced a vitamin D deficiency. This study was published in PLoS ONE, an international online peer-reviewed journal, on Dec. 27.
This third study produced some interesting results, says Hamadeh. When vitamin D deficiency was induced before disease onset, disease severity was reduced, but after disease onset, it was worse. “So at very low levels there is something happening in the cell that is causing them to function better only for a little bit of time, only until disease onset, than they progress regularly,” he says.
The key now is to find out what molecular changes are occurring in the muscle, spinal cord and brain when vitamin D is administered, and that is what Hamadeh and his students are currently working on.
“ALS is the most common motor neuron disease and up until now there is no cure for it. It is also a fast-progressing disease. Between diagnosis and death, there are usually two to five years. We are trying to see whether by modulating the diet, by changing the diet, we can influence not only when the disease starts, but how fast it progresses and whether it can affect lifespan,” says Hamadeh.
“To find a dietary intervention that could influence a fast-paced disease after diagnosis of the disease, meaning after some irreversible damage has happened, means this particular nutrient has to be very powerful to either halt or slow the pace of the disease.”
The model Hamadeh works with suffers from heightened oxidative stress, a state of increased levels of free radicals or oxidants that are produced naturally inside the cell during normal functioning and metabolism. There is an association between oxidative stress and chronic, metabolic, autoimmune, neurodegenerative and neuromuscular diseases, including ALS, Type 1 and Type 2 diabetes, cardiovascular disease, obesity, hypertension, Alzheimer’s, Parkinson’s and multiple sclerosis.
Hamadeh hopes his research and that of his students will help not only ALS, but many other similar diseases that share common mechanisms with ALS.
By Sandra McLean, YFile writer