Sensory acuity: Impact of aging and chronic disease

Chemosensory abilities decline as a result of aging, chronic disease, and the medicines/treatments that are often used to address these conditions. The flavor of food and drink normally results from the multisensory integration of gustatory, retronasal olfactory, and trigeminal cues. Given that most of what we think we taste, we actually smell, it is the olfactory decline that may be expected to have the most adverse impact on the loss of the taste/flavor of, and pleasure in consuming, food and drink. The loss of sensory acuity, together with the dysgeusia that affects a number of individuals may well lead to a range of unhealthy eating behaviors ranging from anorexia at one end through to the overconsumption of salt and sugar at the other. Various sensory strategies have been put forward to tackle the loss of chemosensory acuity, including the greater use of herbs and spices (such as chili), flavor enhancers such as monosodium glutamate, as well as greater use of oral-somatosensory thermal cues (e.g., by formulating nutritionally beneficial ice cream). It is important not to forget the desirable sonic attributes of crisp and crunchy foods, as well as the importance of visual presentation, while also ensuring adequate contrast between the food and the plateware. However, looking to the future, effective intervention strategies for those suffering from a loss of chemosensory acuity will need to move beyond a narrow focus on meeting nutritional requirements in a tasty and pleasant manner to consider the more social/emotional role that commensality can play, especially for those living alone and/or in care.