Pleasure from Food – insights from brain responses to taste

Young and older adults experience similar taste sensations, but like tastes differently. This is one of the most evident outcomes from the research by Heleen Hoogeveen. She successfully defended her thesis on November 30th 2016, at the University of Groningen. Her work was part of a TI Food & Nutrition project, called Sensory & Liking, of which the outcomes provide new leads for product development targeted at the elderly. 

Grandmother likes an extra tablespoon of sugar in her tea, and grandfather wants his potatoes with a heavy sprinkling of salt. In fact, many elderly compared to young adults prefer foods with intense taste. Researchers tend to think that in the elderly decreased taste sensation is related to changes in taste liking. “However, we observed that healthy older adults sense tastes similar to young adults, but show higher liking for sweet and salty tastes”, stresses Hoogeveen.“ This is probably because taste liking is dependent on more factors than taste sensation alone.”

Neuronal processes

Searching for a better understanding of taste liking, Hoogeveen investigated the neuronal processes taking place from the moment the product touches the tongue and stimulates the taste buds to the moment people give their opinion on how they like the taste. She and her colleagues were the first to measure (via functional Magnetic Resonance Imaging (fMRI)) brain activity, in 39 healthy young adults (18-30 years of age) and 35 healthy elderly people (60 to 72 years of age), when tasting sweet, sour, salt and bitter at different concentrations.

In contrast to earlier findings, Hoogeveen found no activity differences in brain areas involved in taste sensations between the young adults and the elderly. This indicates that aging per se is not necessarily related to changes in taste sensation. However, brain areas involved in memory and emotions did show differences between the two age groups. “In elderly these areas showed higher activity, which might explain the differences in product appreciation between them and younger participants.”

Hoogeveen also investigated how the amount and composition of saliva affects taste processing in the brain. “Mucin concentration, as a proxy of viscosity of saliva, was related to activity in a brain area coding taste intensity”, she says. “Perhaps this finding could impact salt and sugar reduction tools.”

Optimizing products

According to the PhD fellow, much food product development currently focuses on how foods can retard the aging process. “In addition to this focus on the nutritional value of food product, there should be just as much attention on optimizing the appreciation of products for the elderly”, she stresses. “Our work indicates the need for such research.”

Hoogeveen, who is looking for a position as a researcher bridging science and the food industry, experienced her time at TiFN as very inspiring. “It is challenging to translate fundamental outcomes towards practical applications. In this project industry partners and scientists communicated concisely and effectively to bridge this gap, providing valuable outcomes for us all.”