The term ‘anorexia of old age’ refers to a condition of loss of appetite, which occurs among many elderly citizens. About 15-20 % of seniors experience an unintended weight loss due to the lacking desire to eat. This may be because of emotional problems, such as depression or sorrow, but in many cases the cause is unknown.
Earlier studies have suggested that loss of appetite among the elderly population may be due to a reduced amount of the hormone ‘Ghrelin’ – a hormone that tells us when we are hungry. A new study led by a group of researchers from Plymouth University, England, have now observed a change in the production of a different hormone in the elderly. This hormone is called ‘Peptide YY’ and is possibly the culprit behind the loss of appetite. To reach this hypothesis, the researchers examined a group of 31 healthy adults in the age of 21-92 years old, whereof 6 of them were over 80 years old. However, the researchers noted that there was a great challenge associated with this experiment. The challenge was to find elderly adults who did not suffer from any health issues.
This was necessary to determine any changes in appetite among the participants, unaffiliated with any diseases. In the experiment, all the participants had to fast for several hours before they were allowed to eat their breakfast, which contained 660 calories. After the participants began eating, the researchers measured the participants’ levels of peptide YY, ghrelin and a glucagon-like peptide 1 (GLP-1) – a hormone responsible for reduced appetite and the release of insulin – with regular intervals during a 3-hour period. In addition, the participants were asked to estimate how hungry they were, how much food they thought they would eat, and how pleasant the food was to eat.
The results of the experiment showed that, compared to the younger individuals, the production of peptide YY was greater in elderly participants over 80 years old. Yet, there were no differences between the age groups in the ghrelin or GLP-1 levels.
Moreover, the results showed that those over 80 years old reported reduced hunger, reduced expected amount of consumption, and they thought that the food was less pleasant to eat compared to the results of the younger participants.
Based on these results, the researchers believe it to be possible that the increased production of peptide YY causes reduced appetite among elderly adults, which causes malnutrition and weight loss. Even though additional studies are necessary to determine the importance of the peptide YY-production in a larger population of elderly men and women, the researchers believe that the most recent results are extremely ‘exciting’. If more extensive studies come to the same results, the researchers can begin working on examining a possible imbalance of peptide YY and maybe even manage to combat this change so that ‘anorexia of old age’ can become a rare phenomenon.
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