Neurogastronomy, essential for restoring the sense of taste in stroke and Alzheimer's patients

Neurogastronomy can help improve the perception of flavour that has been lost as a result of illnesses such as stroke or Alzheimer's disease, or due to treatments such as chemotherapy. This is one of this discipline's main challenges, which is investigating "how the brain creates flavour and why", explains Diego Redolar, a neuroscientist and researcher working in the UOC's Cognitive NeuroLab group.

In the case of cancer patients, treatment with chemotherapy kills all fast-growing cells, which includes both cancer cells and the taste buds and the cells responsible for hair growth. Which explains why these patients lose their hair and their food has a metallic taste. Cancer patients need to be properly nourished more than ever, but they cannot enjoy the food's taste. "The knowledge contributed by research in neurogastronomy may help this type of patient", Redolar explains, who is also professor at the UOC's Faculty of Health Sciences.

In recent symposia, the International Society of Neurogastronomy has given challenges to participants, for example, to compete (in teams whose members are chefs, neuroscientists and food scientists) to prepare the tastiest dishes for cancer patients who have impaired flavour perception and reduced appetite.

Along the same lines, F. Xavier Medina, anthropologist and director of the UOC's UNESCO Chair on Food, Culture and Development, explains that the UOC is working with Hospital del Mar on a project that will start this year to improve our understanding of why postoperative patients usually leave part of their meals untouched. "We think that they might be persuaded to eat more if we change the food's appearance or the colour of the plate", he proposes.

Today, says Redolar, we know that the brain conceptualizes smells as spatial patterns and it builds the perception of flavour from this and other senses. Neurogastronomy wants to find out how the information obtained by the sense of smell is combined with the data provided by the senses of taste, sight, touch and hearing; how it is processed in different parts of the brain; and how it produces this perception. It also wants to determine how it even associates an emotion with it. The UOC professor adds that memory plays a major role in this process, as a bad memory can make you desist from ever trying a food again: "Conditioned taste aversion, which is a type of learning, is very powerful", he continues.

For example, it has been found that a white plate can lead to a strawberry mousse being perceived as sweeter and more intensely flavoured. "Or if carrots are cut in a chip shape and presented lightly roasted, they will be perceived as a delicious titbit for snacking at any time of the day. It's not about genetically modifying the carrots to make them taste better; it's about making our brain believe that the carrots are delicious", the expert says.

The knowledge on which neurogastronomy focuses, Redolar adds, may have very interesting uses, beyond the culinary aspect and its application in industry, and it may also find important applications in health.

As Medina stresses: "Today, people are looking for certain standards in food preparation which can be optimized". However, Medina considers neurogastronomy to be highly "West-centred", in other words, it only studies how foods' flavour is perceived by part of the world's population, and "it pays very little attention to culture".

Taste and smell, little-known senses

In spite of this, it is a young research field with a lot of work ahead. According to the neuroscientist, one of neurogastronomy's greatest contributions is that it seeks to study taste and smell, which are much less known than sight or hearing, "because they are chemical sensory systems and their neural pathways are not so clearly organized in the brain". What the anthropologist finds most interesting is how it works with all the senses. "Gastronomy already does this, any chef will try this, but neurogastronomy tries to be much more conscientious", he concludes.