Enjoyment of taste is one of the great pleasures in life. Yet as we age so do our senses, with the result that our tastes may change over time. Which explains why, among scientists and food companies, there’s growing interest in maintaining – and even improving – our ability to perceive flavours.
Not so long ago, the only wine I’d drink was white. But some time around my mid-40s, my tastes changed. Five years on and I can barely look at a glass of the stuff – though I’d quite happily drink red, any day.
It’s the same story with sugar and coriander; once I couldn’t get enough of either, but not any more.
The fact is, contrary to what many of us might like to think, our enjoyment of specific foods and preference for certain flavours is anything but cast in stone once we reach adulthood. It’s a known phenomenon, and it’s got its own name: the wandering palate.
To understand why our tastes change you must first understand how taste works, according to Professor Charles Spence, an experimental psychologist at the University of Oxford who specialises in the sensory perception of food. He has worked closely with leading food companies and Heston Blumenthal.
Our taste and smell senses are closely related, he explains. Taste comes from our ability to detect molecules that are released when we chew, drink or digest using taste buds and other specialised nerves.
“Flavour perception is one of the most multi-sensory of our everyday experiences, involving not only the taste and smell of a food or drink but also its texture, the sound it makes and even what it looks like,” he says.
“Our enjoyment comes from taste plus smell, but is also influenced by sound and look as well as texture, temperature and even pain – as with chilli.”
Experts agree that there are a handful of basic tastes, including sweet, sour, bitter, salty and the ‘brothy’ flavour of umami. But there are thousands of aromas, just one molecule of which can trigger hundreds of our nose’s olfactory receptors.
Our sense of smell is critical to our ability to perceive flavour. But a variety of external factors also affect our taste: illness and certain medications, for example.
Air pressure can affect the way food tastes on planes, researchers have found. A dry atmosphere can reduce the saliva produced by our mouths so lowering our ability to taste salt, another study suggests. Many women experience strange taste cravings during pregnancy, or fall out of love with a favourite food.
What you taste can be influenced by what metal your cutlery is made from, according to researchers from University College London. In a blind tasting, people found that a steel spoon can give food a salty kick, whereas a gold spoon can make it taste more salty and sweet.
Yet despite all this, the fact remains that as we age so the sensory nerve endings on which we depend to taste different flavours age, too.
As children, most of us will have had around 30,000 taste buds, which make eating a super-sensory experience and, in part, explains why most young children prefer food which is bland. By our late teens, our taste buds have declined by a third.
The number will further decline as we reach middle age. For women, it’s around the time they reach 50; for men, typically, a decade later. Sensitivity to salty and sweet tastes is dulled first, followed by bitter and sour tastes. Much of this will also be due to our ageing olfactory receptors.
However, hope lies in the very fact that our palates do have a tendency to wander, Spence suggests. “Our taste and flavour preferences change across our entire lifetime,” he says.
So, children between nine and 15 typically seem to like sweet, salty and extreme sour tastes more than adults.
Among adults, a liking for robust tastes – Stilton, for example – can emerge through social conditioning or by pairing an unpleasant taste with something you find pleasant, like coffee and sugar.
Meanwhile, loss of appetite and overall interest in food among the elderly could be linked to a decline in ability to enjoy the flavour of umami, according to new research from Japan published in January.
“While there is currently nothing you can do to recover taste or smell once it has been lost over time, you can make greater use of your other senses – texture, for example, and eye appeal – to strengthen your perception of flavour,” he adds. The other thing is practice.
A big predictor of whether we like olives or coriander or oysters is our motivation, our interest in a particular food and its taste, and our exposure to it. Familiarity can ‘sweeten’ any taste, according to a 2010 study in which as few as ten to 15 repeated tastings increased a liking for vegetables among a group of nine and ten-year-olds.
“Food and wine experts don’t have bigger noses or greater sensory abilities than anyone else, just a better ability to name what they are tasting,” Spence says. “Practise this and our perception of taste can be both enhanced and extended over time.”
Young children don’t like any strong flavours (other than sweet, a preference many lose at puberty). They crave, instead, the fat and sugar-packed milk that will make them grow.
Adolescents eschew bitter and sour tastes, favouring sweet-flavoured alcoholic drinks, for example, over those with more traditional tastes.
By their late teens, however, they are likely to reject extreme sweet tastes and may even start liking sprouts
Adults can appreciate more robust flavours such as game, ripe cheeses or anchovies, but can also easily become set in their ways making it harder to embrace new tastes.
Older people add more sugar and salt to their food to enhance its taste as their ability to smell fades. Which is why they have become a growing focus for food companies eager to develop products which are sweeter or saltier in flavour, but healthier by having a lower added salt or sugar content.