This post originally appeared on Decanter.com.
After she turned 60, Californian wine publicist Jo Diaz began noticing that when she tasted wine her sense of smell wasn’t what it used to be. Now aged 68, she says, "It takes me longer to pick up all the parts of a wine’s aromas. I swirl five times to get what I used to pick up in one sniff. But I’m enjoying the process more."
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Savoring a glass of wine is a pleasure we like to think won’t fade as we get older. Our wine-tasting skills might even get better with time, right? With age, hair turns grey, skin wrinkles, and hearing and vision often deteriorate, so it’s no surprise that the ability to smell and taste can fade, too. Research indicates some of us will be lucky and will hang on to most of the abilities we already have, while others will face a downhill slide in our powers of perception. All this is highly individual and a gradual decline in sensitivity may not always be obvious.
"Smell (olfaction) and taste (gustation) are distinct physiological systems," according to Dr. Beverly Cowart of the Monell Chemical Senses Center in Philadelphia, who has been studying aging and the palate for more than 30 years. Each system has its own receptors and neural pathways, but it’s often difficult to work out how each sense contributes to our overall perception of a wine because smell,taste and touch (mouthfeel) all co-mingle in the imbibing experience.
We perceive five basic tastes: sweet, sour, salty, bitter and savoury, or umami (though some researchers argue the latter doesn’t really belong on the list). We start out with up to 10,000 tastebuds, clustered on the tongue, the inside of the cheeks, the roof of the mouth and in the throat. Each tastebud contains specialised receptor cells that send signals to the brain.
By contrast, we can detect thousands of distinct scents, perceiving them through a complex process, which makes it easy to disrupt. How it worked was a mystery until the early 1990s, when Dr. Richard Axel and Dr. Linda Buck, who won a joint Nobel Prize in 2004 for their research, unravelled the network that governs our sense of smell. It starts with the family of 350 odor receptors clustered at the top of the nasal cavity. There are thousands of specific aromas, and only a single molecule is needed to light up one or more olfactory receptors.
Smell sensitivity varies widely from individual to individual thanks to quirks of physiology. Some people are "smell blind" to certain chemicals, such as TCA, or cork taint, for example.
On the decline
Cowart and other researchers now know that the ability to smell fades much more than the ability to taste. Taste, says Dr. Linda Bartoshuk of the University of Florida, is our most stable sense. There’s some evidence the number of tastebuds declines with age, but people may not notice this because they’re scattered throughout your mouth. If you add in the physical sensations of texture, you can still discern much from a mouthful of wine.
The taste we start losing first is our sense of bitterness. Bartoshuk says it declines in a measurable way over a lifetime for men, while for women it starts at menopause. Other studies have indicated that perception of salty tastes decreases more than sour and sweet ones.
When it comes to the sense of smell, the U.S. National Institute of Aging reports that 30 percent of Americans aged between 70 and 80 and nearly a third of those aged 80 or older have some problems, while a 2002 study found 62.5 percent of 80 to 97 year olds had some smell loss. "The degree of decline varies widely," says Cowart. It becomes harder to discriminate among smells and particular aromas that we lose sensitivity to can vary wildly from person to person.
There are plenty of theories around why smell and taste decline with age. Living in a polluted environment, for instance, hugely affects the sense liver problems and diabetes as well as sinus infections, ear infections and viruses like hepatitis and flu play significant roles in declining sensory perceptions through cell death and inhibiting the regeneration of olfactory receptors. Many affect taste as well as smell. Saliva plays a huge role in taste, so medications that dry your mouth impact what you taste. And too much alcohol can irritate tastebuds as well as cut down smell sensitivity.
We also know a blow to the head can knock out the sense of smell. U.K. wine trade veteran Harry Waugh was an active taster in his 80s when he hit his head in an automobile accident and lost his sense of smell; thereafter he relied on taste and mouthfeel rather than nosing a wine. When wine critic Robert Parker Jr. struck his head in a biking accident in 2002, he rushed home and poured some wine into a glass to make sure his famed sense of smell hadn’t been impaired.
Memory also augments our powers of smell discrimination. A 2011 study of perfumers conducted by Jean-Pierre Royet, a neuroscientist at the University Claude Bernard in Lyon, France, showed that much of the ability to detect and identify thousands of different odours depended on how much training each individual had. Royet and his researchers compared the brain scans of novice perfumers and those with up to 35 years of experience while they tried to identify dozens of odours. Both groups scored well, but the pros were more accurate and faster and used a different part of the brain—the area involved in memory recall.
Wine professionals may compensate for a lessened ability to nose out nuances by relying on their experienced palates and detailed taste memories. California-based Dan Berger, 73, who’s been writing about wine for almost 40 years and organizes and judges wine competitions, believes his palate memory is "better than it has ever been" because the vast number of wines he’s tasted from around the world "conjure up sense memories I never had when I was younger." This is one way that age can be a positive factor in how our brains read smell and taste signals.
Berger reports that the late critic Robert Balzer stopped judging wines at age 95, not because his palate was any less sharp, but because he was very slow. And Mendocino winemaking legend John Parducci, who died last year, asked Berger to remove him from the red wine panel at one competition when he turned 87 because he felt he couldn’t judge reds with enough accuracy any more, though he remained good at whites.
Bartoshuk says loss is not all bad, even if difficult to adjust to at first. She points out that our brains are wired to make new connections. Diaz, for instance, says she has come to prefer highly aromatic whites like Torrontes and Viognier. In the same way that a number of athletes in their 70s are still running marathons, some people retain their critical wine faculties into late age.
And a great taster in decline might even be more discriminating than a normal person in their prime. I recall a dinner at which the great Napa Valley wine collector Barney Rhodes, in his late 70s, nodded off, then woke up to identify a mystery wine poured into his glass.
Scores of older winemakers, importers, brokers and sommeliers are still using their noses and taste buds to make critical decisions on wines—a fact that should give ageing wine lovers reason to continue to have confidence in their own wine opinions.
Paul Draper, the much-lauded chief winemaker at California’s Ridge Vineyards, will turn 79 this year and has been making some of the state’s greatest wines at Ridge since 1968. Draper admits he’s able to be more perceptive when he tastes only four to six wines in one sitting. "I feel more confident about my descriptors and my assessment," he says.
Of course, he’s assessing wines critically on a constant basis. Lytton Springs and Monte Bello, to name two of the winery’s top vineyards, have many parcels, so major blending tastings require fine discrimination. He’s still up to the task. "I’ll step back when I can no longer smell or taste," he insisted. "But that time has not come just yet!"