Information on Taste Disorders
The Smell, Taste and Flavour page of our site explains how anosmia results in a marked reduction in the ability to detect flavour in food and drink, and how many patients who believe they have problems with their taste are, more often than not, suffering from a smell disorder.
However, there are instances when a person’s ability to taste food is compromised whilst their sense of smell is unaffected. For example, loss of the sense of taste (ageusia) means that the ability to detect the basic tastes, sweet, sour, bitter, salt and umami, is lost, but the sense of smell is unaffected. Taste-specific disorders are far less common than smell disorders, for example only 3% of the patients who have passed through Carl Philpott’s Smell and Taste Clinic at James Paget Hospital have suffered from a taste disorder.
‘It started after a very bad cold that seemed to go from person to person in my household, eventually making it’s way to me, just in time to ruin the Christmas pleasures of smells and tastes that fill our household around that time of year. Although as the cold wore off it, it had taken a lot more than just a week of my life feeling under the weather, and brought with it a strong metallic taste in my mouth, one that would not go away.
I was plagued by this metallic taste for a week, and it affected my sleep and everyday life until finally it went away – along with my sense of taste. It took the best part of a few weeks for me to understand that I’d lost my sense of taste, because my sense of smell is unharmed and fully functioning. It was only when I had a glass of fresh cold orange juice one morning and realised that it tasted completely the same as water. That’s when I started holding my nose and eating different foods, extra strong mints, lemons, onions – all tasted the same.
What does it feel like to eat food that you can’t taste? Well, it’s a very strange experience, due to the majority of flavour coming from the food or drink’s smell. I can feel textures, the viscosity of liquids, I know how chewy or light the food is, I can feel the spice (something you don’t taste, you feel), but I just can’t extract any flavour from it. Bitter, sweet, salty, savoury or sour is irrelevant, as they all give the same experience.
Take a brandy for example, hold the glass near your nose and the strong brandy alcohol sensation hits your nose and is an extremely powerful smell, but once the liquid goes into my mouth it becomes the same as water, until I swallow it, and then the alcohol warm sensation is on my throat. Foods that are chewy are now my nemesis, due to them spending a long time in your mouth for the purpose of flavour extraction, something that is not happening in my mouth, so it’s made me change the way I eat as well as having a massive impact on wanting to eat in the first place, as food has no appeal to me anymore, it’s just become part of a daily process.
There can be a lot of confusion amongst people with a smell or taste disorder as to which sense it is that has the problem. Carefully experimenting with foods and flavours can help you identify whether it is your sense of smell, taste, or both that is causing the issue.’
Causes of Taste-specific Disorders
These are wide-ranging, and the list below is not exhaustive. The most common cause of taste loss is ageing, as with smell loss.
– Medications – taste impairment is an unwanted side-effect of many medications, with some actually altering the way that flavour is perceived; numerous drugs, for example, including some used as part of treatment for cancer can cause a metallic taste in the mouth. Others can interfere with saliva production, or disrupt the function of taste cells in the mouth.
– Damage caused by ear, nose, or throat surgery
– Chemotherapy for (typically) throat cancer
– Neurological disorders, i.e. strokes, epilepsy