It’s probably one of the lesser-reported symptoms of MS, but a research team at the University of Pennsylvania’s Smell and Taste Center concluded in March 2016 that there is a high incidence of poor ability to identify taste by people with MS.
MS loss of taste & metallic taste in mouth
Little had previously been known or studied regarding the relationship between taste and MS, although former research estimated that between 5 to 20% of people with MS experienced some kind of taste dysfunction.
However, the article Taste Dysfunction in Multiple Sclerosis, published in the Journal of Neurology, concludes that not only are taste deficits more common than previously realised, but that the extent of this dysfunction correlates with the amount of damage in the brain, as revealed by MRI scans.
The study’s aim was to assess the ability to identify bitter, sour, sweet and salty tastes on different regions of the tongue, and compared 73 people with MS to 73 people without the condition across a 96-trial test of the four tastes, recording a ‘dysfunction’ when taste recognition was below the fifth percentile of the control group.
For the MS group, salt appeared to be the hardest taste to appreciate, with 31.5% falling below the normal level. Twenty-five percent had trouble recognising a sweet flavour, 22% with sour, and 15% with a bitter taste. Frequent reports also suggested a temporary metallic taste in the mouth.
Female vs male taste buds
Furthermore, the researchers were able to identify that the taste scores were inversely proportional to the amount and volume of lesions which were evident on MRI scans of the different brain regions.
The study’s lead author and director of the Smell and Taste Center, Dr Richard Doty concluded that “This study represents the most comprehensive study performed to date on the influences of MS on the ability to taste. It appears that a sizeable number of these patients exhibit taste deficits, more so than originally thought.
This suggests that altered taste function, though less noticeable than changes in vision, is a relatively common feature in MS.
These findings give us a better insight about the areas of the brain that are more likely to impact the dysfunction when scarred from the disease.” A consistency between the groups with and without MS was that women fared better on the tests than men – a result attributed to the fact that women have more taste buds than men.
Professor George Jelinek from OMS commented that the researchers didn't mention that this raises the possibility that how well people with MS can taste flavors could be used as a marker of the progression of the disease.
If it correlates closely with MRI disease activity and damage, then preservation of taste function could be used to indicate that the disease is not progressing, rather than subjecting people with MS to repeated MRIs.
It also fits neatly in with our focus on mindfulness and mindful eating: to be aware and really taste our food is one focus of the OMS Program. Honing that skill and preserving that function is a pretty good barometer of wellness!