As Daniel Patrick Moynihan, an American sociologist, politician, and diplomat once said: “Everyone is entitled to his own opinion, but not his own facts”. And we wholeheartedly agree. A shared set of facts is the first step to building a better world with longevity for all. In that spirit, we are creating a series that covers 101 indisputable facts about ageing, health and longevity.
More so than many of the other ways in which we experience our environment, flavour is a complex phenomenon that is made up of multiple senses. The most important of these are the basic sense of taste for which the taste buds on our tongues are responsible, and the sense of smell. The former detects the salty, sweet, bitter, sour and savoury tastes, which are combined with smell to produce the overall flavour. Additionally, the temperature, texture and visual appearance of food can also impact how we experience taste.
During ageing, the taste sensation by the tongue is usually impacted earlier than sense of smell. The number of papillae (the structures containing the taste buds) on the tongue begin to decline as early as one’s 40s, while those that remain change in shape, becoming more ‘closed’ and making it harder for chemicals within the food to contact taste buds within. This results in a reduced ability to detect the 5 basic tastes. Studies have found this decline to be more significant in males, though not all are in agreement about which basic tastes this gender difference applies to.
Some other less obvious factors also affect sense of taste during ageing, including decreased oral health (leading to poorer chewing) and decreased saliva production. These changes mean that food is not broken down as much in the mouth and there is less fluid to carry food chemicals to the taste buds. As covered in fact #22, sense of smell also declines with age, with a steep decline usually occurring after the age of 60. This reduces the ability to detect those aspects of flavour that are associated with specific foods, but is not strictly part of the sense of taste and so will not be covered in greater detail here.
Loss of taste is an important contributor to loss of quality of life in the elderly. Losing one’s sense of taste can lead to disinterest in food, and also makes it harder to notice when food is spoiled. Fortunately, the extent of taste decline varies greatly from one individual to another, and preliminary research suggests that maintaining good general health and oral hygiene is associated with lower levels of impairment.
How our sense of taste changes as we age: https://theconversation.com/how-our-sense-of-taste-changes-as-we-age-112569
Taste Perception with Age: Generic or Specific Losses in Threshold Sensitivity to the Five Basic Tastes? https://doi.org/10.1093/chemse/26.7.845