Taste and smell changes fuel cancer malnutrition, dsm-firmenich review finds

Cancer patients face unique challenges to food consumption that can lead to malnutrition and thereby reduced treatment tolerance and response. Experts at dsm-firmenich explain to Nutrition Insight how cancer and its treatment affect patients’ taste and smell, while calling for routine monitoring of these alterations, as they are often overlooked in clinical practice. 

There must be standardized assessment methods to improve communication about sensory experiences between patients and health care professionals, urge Marie Bouvet, director of Innovation & Science Medical Nutrition, and Lyzandra Passarella-Dutour, senior director of Technical Taste.

Reflecting on new literature on sensory issues affecting nutritional intake and treatment outcomes in cancer patients, Bouvet shares that her team partnered with Dr. Ruben Hack, a medical oncologist at the Cantonal Hospital of Winterthur, Switzerland, to conduct a literature review.

“Insights were collected from more than 150 peer-reviewed papers to better understand the prevalence of taste and smell alterations (TSAs), underlying mechanisms, and impact on the patient experience, as well as identify strategies to support those affected,” she says.

“TSAs are an extremely common side effect of cancer and its treatment. Some reports find that up to 60% of patients experience changes in their sense of smell, while as many as 90% experience taste alterations. How these are experienced also varies from patient to patient and even over the course of treatment.”

Bouvet shares that some patients experience a complete loss of sensation, while others have heightened or reduced sensations, and some experience “phantom” sensations in the absence of stimuli. In one study of cancer patients, 58% of those with taste alterations reported a metallic taste, one of the most commonly reported changes, she notes.

Marie Bouvet calls for validated questionnaires so patients can report taste and smell changes.“Understandably, individuals with TSAs usually experience reduced enjoyment of food, which can have a significant impact on quality of life during an already difficult period,” says Bouvet. “One study found that taste alterations were among the most distressing treatment side effects, affecting patients’ daily lives.”

“Moreover, loss of food enjoyment and appetite strongly impacts nutrient intake and therefore nutritional status. This makes TSAs a significant contributor to malnutrition in these individuals, which can have devastating impacts, including decreased tolerance and response to therapies, and, in some cases, reduced survival rates.”

Standardizing TSA assessment

According to Bouvet, TSAs are often overlooked in clinical practice for several reasons, including being treated as less urgent than side effects such as pain, nausea, or diarrhea.

“There is also a lack of established, standardized screening methods to diagnose, monitor, and address TSAs. In our review with Hack, we highlighted the need for simple, validated patient-reported questionnaires and more standardized assessment approaches to better monitor TSAs.” 

“This would help patients to communicate their sensory experiences and how they impact their nutritional intake and quality of life with care teams, who can then adapt supportive strategies as needed over time.”

Passarella-Dutour adds that establishing such systems could let patients report TSAs, so those affected could receive medical nutrition with sensory-adapted flavor profiles.

Lyzandra Passarella-Dutour says medical nutrition only works if patients are willing to consume it.“Sensory-adapted nutritional solutions have already been well received by patients undergoing cancer treatments in clinical testing, including those experiencing TSAs. And because TSAs can change throughout treatment, nutritional recommendations can evolve with them,” she says.

“If patients later develop heightened bitter perception, for instance, their nutritional care could be adapted accordingly, helping to support intake and nutritional status as their needs change.”

Medical nutrition potential

According to Passarella-Dutour, medical nutrition products are effective only if patients are willing and able to consume them. She cites evidence that sensory-adapted solutions help patients accept food and nutritional supplements.

“Designing sensory experience into medical nutrition products from the outset can help improve adherence and support nutritional intake,” she says. “Different formulation approaches can be considered depending on the product’s nutritional composition and the specific sensory alterations experienced.” 

“dsm-firmenich has an advanced toolkit bringing together patient and consumer insights, medical nutrition expertise, flavor creation, taste modulation, premix, application, and sensory science.”

Passarella-Dutour highlights the company’s ModulaSense for addressing heightened perceptions, such as bitterness, metallic notes, acidity, and ingredient-specific off-notes.

“This strategy is particularly useful for oral nutritional supplement (ONS) formulations containing high levels of ingredients such as peptides or proteins, which can introduce multiple off-notes that can negatively affect the sensory experience and, ultimately, product adherence.”

Bouvet says close collaboration between clinicians, researchers, patient groups, and the nutrition industry can help build the evidence base.“Beyond masking unwanted tastes, sensory variety may help maintain the appeal of medical nutrition over time. The need for this becomes clear with longer-term use. dsm-firmenich [internal, unpublished] research indicates that 60–70% of oncology patients experience flavor fatigue or taste boredom after several weeks of ONS use.”

She also spotlights dsm-firmenich’s Novasense sensates for sensory enhancement, adding that studies on patients undergoing cancer treatment report positive results for warming and cooling sensations. Other research on older cancer patients undergoing treatment shows flavor modification strategies can boost nutritional intake and quality of life.

What is needed now?

Despite evidence supporting sensory-adapted solutions for cancer patients, Bouvet and Passarella-Dutour highlight where the science is still thin and what industry and researchers need to address as they build solutions.

“There is a need for more systematic assessment and robust clinical evidence to build understanding of the factors influencing TSAs, how they vary between patients, and which approaches are most effective in managing them,” says Bouvet.

“Progress in research and product development can happen in parallel, though: close collaboration between clinicians, researchers, patient groups, and the nutrition industry can help build the evidence base while translating emerging insights into solutions that better meet patients’ needs.”

Adding to the discussion, Passarella-Dutour highlights that dsm-firmenich contributes to this space by helping bridge patient insight and product development via patient research and sensory studies. These studies help identify needs and suitable approaches, from taste modulation to sensory-enhanced solutions.

“With our medical nutrition customers, we can then help translate these insights into the design of medical nutrition products. Ultimately, stronger clinical evidence and closer cross-sector collaboration will be essential to turn sensory insights into validated, patient-centered solutions that support nutritional intake and quality of life throughout cancer treatment,” she concludes.