Overview: Olfactory dysfunction can have both physical and social consequences, in addition to affecting food intake and weight. Researchers say foods that stimulate other chemical senses when consumed, such as chili or menthol, may improve the quality of life for people with smell disorders.
Source: University of Aarhus
Smell plays a key role in our ability to enjoy food. However, many people suffer from a lost, diminished or distorted sense of smell, and this can affect both their health and their quality of life, according to a new study from Aarhus University.
Losing your sense of smell or distorting it affects more than your cooking and eating habits, says Alexander Wieck Fjældstad, associate professor, MD. He was part of the founding of Denmark’s first clinic for smell and taste, and is the author of the study recently published in the scientific journal Foods.
“Reduced pleasure from eating and its social consequences are very important for patients and often have serious consequences for their quality of life,” says Alexander Wieck Fjældstad.
The study also shows that 39 percent of patients with severe odor disorders have a significantly increased incidence of weight loss, which can negatively impact their health.
Finish cooking as soon as possible
A total of 692 people answered a questionnaire about cooking, smell, weight changes and sensory awareness for the study. 271 had lost or had a decreased sense of smell (olfactory dysfunction), 251 had a impaired sense of smell (parosmia), and 166 were part of a control group.
The research shows that patients with a disturbed sense of smell differ from the control group in terms of food preferences as well as the ability and desire to cook.
“The patients expressed the wish to finish cooking as soon as possible. They do not find cooking as enjoyable as before, they are less interested in cooking for others and have lost the desire to try new foods. And less variation in eating habits can affect health,” says Alexander Wieck Fjældstad.
Previous studies have also shown that the loss or distortion of the sense of smell can have consequences ranging from social insecurity and an increased risk of depressive symptoms to an increased risk of household accidents.
How do you rediscover a sense of pleasure?
Fortunately, the recently published study explains how foods with different base flavors, textures and mouthfeel can increase a patient’s pleasure. When a food odor released into the oral cavity is not intercepted by the smell receptors in the nose, it is possible to compensate by focusing on other sensory inputs.
In other words, the other senses can enhance the eating experience, so that the patient is more satisfied with food, a better multisensory eating experience, and an improved quality of life.
“The patients find cooking a challenge, but the research can help because it makes clear which ingredients are unpleasant or pleasant if your sense of smell is impaired,” says Alexander Wieck Fjældstad.
He cites dried fruit, chili, menthol and canola oil as good food options for patients with impaired sense of smell and taste. When eating these foods, the mouthfeel provides sensory stimuli when the sense of smell fails.
In particular, patients with impaired sense of smell should avoid coffee, mushrooms, butter, ginger, black pepper, and toast, as these foods generally provide significantly less pleasure. This is due to a combination of a higher incidence of distorted odor detection and the fact that some of these foods strongly stimulate the other chemical senses, which becomes unpleasant when there is no aroma.
The consequences of a disturbed sense of smell when cooking and which foods really work for patients have not been studied before.
A common problem
Taste is a multi-sensory process where each sense contributes with different tones that together result in a complex symphony that allows us to identify what we eat, assess its freshness and edibility and ultimately give us a sense of pleasure. Few people realize how important the sense of smell is until they lose it.
However, in the wake of the Covid-19 pandemic, we have become even more aware of the importance of scent. About 65% of the more than 300 million Covid-19 patients worldwide have experienced a loss of their sense of smell. For more than half of those patients, the loss or distortion may be long-lasting.
“In connection with Covid-19, many people have experienced losing their sense of smell or becoming distorted, but actually it has always been a common problem,” says Alexander Wieck Fjældstad.
Fifteen percent of the population has a reduced sense of smell. The problem increases with age and is often linked to many well-known diseases such as diabetes, kidney disease and various neurodegenerative diseases. About two percent of Danes suffer from a complete loss of sense of smell.
About this news about olfactory research
Original research: Open access.
†The effects of olfactory loss and parosmia on food and cooking habits, sensory awareness and quality of life – a possible way to enjoy food againby Alexander Wieck Fjældstad et al. Food
The effects of olfactory loss and parosmia on food and cooking habits, sensory awareness and quality of life – a possible way to enjoy food again
Olfactory dysfunction often has serious consequences for patients’ quality of life. The most common complaint in these patients is their decreased enjoyment of food in both patients with loss of smell and parosmia.
How the different types of olfactory dysfunction differ in relation to food and cooking habits, sensory awareness, and food-related quality of life has not yet received much attention.
By applying questionnaires on cooking, eating, olfactory function, weight changes, sensory awareness, and food-related quality of life, we examined how different aspects of eating differ among participants with olfactory loss (n = 271), parosmia (n = 251) and normosmic controls (n = 166).
Cooking habits in olfactory dysfunction revealed marked differences compared to normosmic controls. Cooking with olfactory dysfunction was associated with, for example, a lack of comfort and inspiration for cooking and an inability to make new foods successful. Significant differences were also found in cooking between loss of smell and parosmia.
Food items were less well known among participants with olfactory loss and parosmia, while ratings of food liking differed between olfactory loss and parosmia, indicating the importance of individually adjusting ingredients in meals for olfactory loss and parosmia.
Parosmia was associated with a higher incidence of weight loss, but we found no difference in food-related quality of life between participants with loss of smell and parosmia.
While loss of smell and parosmia have far-reaching implications for patients’ cooking and dietary habits, adapting meals to “safer foods” and incorporating multisensory stimulation may be a potential way to enhance the enjoyment of food.