Taste the difference: How our genes, gender and even hormones affect the way we eat

Do you often loathe the foods that others love? Then maybe you're a 'supertaster'

(FACUNDO ARRIZABALAGA)

Try it, it's delicious!" I often urge my children, bossily. And although I don't say it out loud, I feel equally baffled when adults are really faddy eaters or don't share my adoration of a particularly tasty morsel. It turns out I'm not a food fascist but contrary to popular belief, there is no one version of delicious. Some of us have a far stronger sense of taste than others (not necessarily a good thing) and a host of factors ranging from mood to gender to our sense of hearing (really) can impact heavily on our perception of flavour.

Psychologist Linda Bartoshuk and her colleagues first coined the term "supertaster" in the 1990s. In their research, they noticed that some people seemed to have a much higher taste response than others. But don't be fooled by the label. We're not talking about a superior palate . Far from it, Bartoshuk found that supertasters – which make up around 25 per cent of the population – carry a double copy of a gene which makes them super-sensitive to bitter tastes. Among the things they hate are green vegetables, grapefruit juice, coffee and soy products, as well as overly sweet things. At the other end of the spectrum – also 25 per cent of the population – are non-tasters, whose "pastel world" of flavours is far less sensitive, with the remaining 50 per cent somewhere in between.

Women are much more likely to be supertasters than men (35 per cent of women vs 15 per cent of men) and more Asians are supertasters than the rest of the world. Caucasian males have the lowest rate of supertasters of any known group.

Charles Spence, director of the Crossmodal Research Lab, part of Oxford University's Department of Experimental Psychology, says the discovery has huge commercial potential. "Already in some markets, such as toothpaste, companies have multiple brands that are targeted at supertasters or non-tasters," he says.

He reckons the next step is experimental chefs noting customers' reactions to an amuse-bouche before each meal and adjusting the dishes that follow to maximise their satisfaction. "If a quarter of the population have a strong reaction to some tastes and another quarter have no reaction, it makes no sense for everyone to be given the same dish. There's the potential to go out to dinner and leave not just having had a good meal, but knowing far more about your own taste."

Spence's research has shown that perceptions of taste and flavour are not only genetically determined, but influenced by all our other senses. "Most people know of the link between smell and taste, but we've found taste is far more multisensory, including sight. If you put red colouring in white wine, for example, even wine experts perceive the flavour differently. In fact, the more expert they are, the more they are fooled. They drink the white wine and talk about the buttery, straw-like flavours and when you give them the same wine with red food colouring, they describe the tobacco and chocolate-like flavours."

The colour of ambient lighting can influence how wine tastes. Then there's hearing. Heston Blumenthal's famous "sounds of the sea" dish (where diners eat a fish pie while listening to the seaside through an iPod) served at the Fat Duck in Bray, came about from collaborative experiments with Spence. "What you hear at the time of eating can hugely alter your perception of what you taste," he says, adding that experiments have shown that foods like carrots begin to taste unpleasant if you take the crunchy sound away.

We all know how hormones can affect perception of taste (pregnant women and food cravings), but mood has an impact too, says Lucy Donaldson, a senior lecturer in physiology and pharmacology at the University of Bristol. "Anxiety and depression can make things taste of cardboard. That's not just the effect of the anxiety not allowing you to concentrate on eating. The brain actually activates what happens on the tongue," she says.

Like many food researchers, Donaldson is not convinced the supertaster is as simple as was first thought. "The idea that they can be identified by a dislike of bitter tastes alone ignores the physiological rewards of food," she explains. "People learn to like red wine because they get the reward of the hit of alcohol. Then there's the fact that some people like bitter things, even if they experience bitter tastes strongly. There are also environmental influences. For example, I think my daughter is a supertaster but she loves broccoli and that may be because of things like being exposed to it in the womb."

Julie Mennella of Philadelphia's Monell Chemical Senses Centre gave expectant mothers either carrot juice or tomato juice during their pregnancy, and tested the infants' preferences after birth. The babies whose mother drank tomato juice didn't like the carrot juice and vice versa, showing that taste preferences develop in the womb. "At birth, the baby will already 'know' what people in his or her culture eat, and have a preference for these foods," says Virginia Utermohlen, associate professor at the Division of Nutritional Sciences at Cornell University, New York.

You can become conditioned to foods after birth, she believes. "In our culture, for instance, we are conditioned to view bugs as 'dirty' and not food, but in other cultures bugs are eaten happily. You can also be aversively conditioned to a given food if you get sick after eating it, whether it was the food that made you sick or not. I became – and still am – disgusted by a certain kind of tomato sauce with parmesan cheese that I once liked, because I was very sick after, though due to something different."

One blessing is that on average, we become less sensitive as we get older, says Utermohlen. "In particular, the transition from childhood to adolescence increases the ability to tolerate food. Similarly, as we get past 40 there is a decline in taste and smell sensitivity, which may allow tolerance of more foods. This doesn't occur at the same pace in everyone, though. In one study, chefs on average showed less decline than others."

Neil Martin, director of the Human Olfaction Laboratory at Middlesex University, believes you can retrain your taste. "If you like sugar in tea or coffee and you eliminate the sugar immediately, you'll find it horrid. But if you do it over a period of weeks – say, by a quarter of a teaspoon a week, by the end you will probably find the amount you originally had far too sweet. It never ceases to surprise people."

At Green & Blacks, Micah Carr-Hill, the head of taste, is seeking a taste assistant. Most such posts require someone with huge experience in the food industry and/or food science and whilst Micah says his new recruit may have such credentials, more important is someone with a passion for food and a natural ability to taste critically.

Keen to test my abilities, I waste no time in applying. If I can identify the secret ingredients in a chocolate bar specially concocted for me by Micah himself, I'm told I'm in with a chance. Next thing I know, I'm standing in the G&B kitchen in Berkeley Square London taking my first bite of said chocolate bar. Yum. "Chilli?" I announce, self-assured. Yes, nods Micah. Good start. "Orange?" No. "Lime?" No again. "Vanilla?" Nope. I take another bite. And another. Not a clue, I eventually have to admit, and could kick myself when he says ginger (of course!) although there's no way I'd have guessed rose petals, juniper, nutmeg and white pepper.

If, as Micah believes, the potential to taste critically or even to identify individual flavours is something you're born with, clearly I wasn't. But even being blessed at birth isn't enough. Once a year, following the wine harvest, Natasha Bridge, the head blender of Taylor's, Fonseca and Croft Ports, spends five weeks tasting 20 to 30 wines every morning. "Having to pick out the nuances is incredibly specialised work and without a huge amount of training, it wouldn't be possible," she says.

There's no room for blagging, points out Cathy Chapman, head of product development at M&S, who in the past has been screened and re-screened for her susceptibility to things like salt. Meanwhile, Sandra Ziles, head of own-brand at Ocado, believes a lot of the ability to taste critically comes down to keeping up with trends. "I have to eat out in masses of restaurants so I understand excellent quality and authentic tastes, as well as British versions of authentic tastes. I also have to work very hard at maximising my taste buds by ensuring the lighting, smells and noises around me are taken into consideration."

Whilst some go as far as insuring their sense of taste for millions of pounds, what I've learned is that my own isn't even worth giving up the day job for. I've also learned that next time someone doesn't share my love of some exotic fusion dish or plain old Brussels sprouts, I should be a bit more forgiving. Taste, it seems, can be a humbling business.

To learn about Green & Black's nationwide search for a taste assistant go to www.pieceofgreenandblacks.com

Are you a supertaster?

The easiest but least home-friendly test is to get some propylthiouracil (PROP), a prescription-only thyroid medication drug. In this test, widely used by taste researchers, people are made to taste PROP and if they find it repulsively bitter, they're deemed a supertaster.

For the home-friendly version, use a hole punch on a small piece of card and then rub some blue food colouring on your tongue. Place the paper with its hole over your tongue and press gently. Use a magnifying glass and mirror to count the number of papillae you see through the hole in your paper – these are the tiny pink dots on your tongue that won't go blue. If you have anywhere around 35 or more, you're probably a supertaster. Less than 15 and you're most likely a non-taster.

No time for experiments? Ask yourself, do you have many foods that you hate? Do you get a strong cooling effect from mint? And do you find foods like this objectionable: green vegetables, grapefruit juice, certain alcoholic beverages, coffee, green tea, soy based products and overly sweet things? If the answers are overwhelmingly yes, you are probably a supertaster.