There is no doubt that the sense of taste (gustation) is a complex physiological phenomenon – I wrote about it here just last month. Now it’s time to venture into the world of taste disturbances.
Imagine never being able to taste food again, or anything for that matter. Imagine everything you eat tasting metallic and just yuck. It is obvious that being able to taste is essential for enjoying food. Not surprisingly, subnormal taste typically leads to poor appetite, which can result in malnutrition, reduced immunity, inhibition of psychological wellbeing and poor quality of life. Unfortunately this is not uncommon.
There are many things that affect one’s ability to taste:
- Drugs and medications
- Nerve diseases
- Radiation therapy
- Zinc deficiency
- Head injury
- Poor oral hygiene
- Dry mouth
- Taste bud or mucosal lesions
- Gum disease
- Gastrointestinal diseases
First on the list above is ‘age‘ – it is well known that elderly people have a lower taste sensitivity compared to the younger generations due to a smaller number of taste buds and lower taste sensitivity. A study from a while back showed that compared to young people, elderly people required 2-3x more salt in tomato soup simply to detect the salty taste. Woah. It is clear that an excessive amount of salt in the diet is strongly associated with poor cardiovascular health and in fact, coronary heart disease is the leading cause of death in Australia. We are on a bit of a tangent here, but it’s important to understand where taste impairment lies within the complex system of the human body, health and longevity.
You might have noticed that it’s not just physical changes to the taste buds that can disturb the way we taste. Changes in taste also stem from changes in saliva production, nerve pathways and the brain. Cancer patients undergoing chemotherapy often experience distortions to their taste, which can be so severe that poor compliance to cancer treatment and malnutrition result. What can we do about taste disturbances?
Firstly, lets learn some new lingo. Hypogeusia refers to a reduced ability to taste; ageusia is the total lack of taste; and dysgeusia is the distortion of taste. Someone with disturbed taste may experience one or all three of the above abnormalities. Other ‘-geusias’ are described here.
Now that we have some lingo down pat, we can move onto the treatment and management of taste abnormalities. Of course, the interventions differ depending on the symptoms the individual is experiencing and the cause of the taste disturbance. A systematic review showed that patients with zinc deficiency or spontaneous taste disorders of unknown cause had improved taste after zinc supplementation for three months (note: this is a very specific finding and can’t be generalised for everyone with taste disorders). Half of the studies involving zinc supplementation revealed side effects such as eczema, nausea, abdominal pain, diarrhoea, constipation, reduction in blood iron, increase in blood alkaline phosphatase and increase in blood triglycerides. There is low quality evidence (single blinded studies with a small number of participants) to show that acupuncture may improve taste discrimination without any side effects, however further studies are required before any conclusions can be made.
So zinc supplementation and to a lesser extent acupuncture might be helpful for some taste disturbances, but what can we do from a food and nutrition perspective? There are many useful tips for improving the taste of food, particularly for people undergoing cancer treatment:
Add seasonings; herbs and spices are great for adding flavour to food! Some suggestions are basil, oregano, dill, parsley, cumin, coriander, chilli, pepper, rosemary, cinnamon… It is always a good idea to keep an eye on the amount of salt and sugar added to food to ensure a lack of taste isn’t overcompensated for.
Cook with flavoursome foods; include ingredients such as onion, garlic, ginger, cheese, sauces, pickles, lemons and oranges in recipes. Learn more about the 5 different tastes and the concept of flavour in my previous article.
If food is too salty or acidic; add honey or table sugar.
If food is too sweet; add vinegar, lemon juice, salt, instant coffee, plain yogurt, sour cream.
If food tastes too strong; try eating cold or room temperature foods such as dairy drinks, cheese and crackers, salad with chicken.
Marinate meats in fruit juice, Asian-style sauces, honey or wine.
If red meat is unpleasant; try fish, chicken, eggs or dairy.
Vary the colour, texture and temperature of foods; whether food tastes too strong or doesn’t taste at all, playing with other sensations can make eating enjoyable again! This may involve having fluids through a straw to avoid chewing or adding croutons to incorporate crunch.
Experiment experiment experiment! The person experiencing taste disturbances is the best person to try out different strategies to determine what works and what doesn’t. The aim is to enjoy food and ensure the body is receiving adequate nutrition.
Side note: some ‘taste’ changes may not be taste changes at all, but rather a change in the perception of the taste. Confused? Consider this: a client reports that they have “gone off a food” because it tastes different, well it may just be because they simply don’t have a neurological emotional attachment to that food anymore. Things change. Yep, it’s tricky. Again, experiment!
The intention of this article is to raise awareness of taste disturbances and management. Please seek medical advice or see an Accredited Practicing Dietitian if you, or someone you know is experiencing taste disturbances.
Photo by Molly Warner