Tastebud tales

There's a BBC Radio 4 Podcast called the Kitchen Cabinet that I listen to in the gym, a kind of foodie question time. It's full of fun facts and anecdotes about all sorts of food, and makes me laugh out loud less than Friday Night Comedy, which always leads to strange looks as I cackle away to myself on the treadmill!
On one recent episode, Peter Barham, the programmes resident food science expert, talked about tastebuds, and I discovered that what I was taught at school was completely wrong.

I was taught that the taste buds are grouped together on specific parts of the tongue, each area either sensitive to sweet, salt, sour or bitter. But that's so last century! For a start there are now 5 recognised flavours - the previous 4 and umami, a savoury sensation, like Parmesan cheese. Some scientists are suggesting that fat is also a recognised flavour and I guess there may be more yet to be identified.
It's now been recognised that our taste buds are scattered over the tongue, not grouped in one specific area - and this makes sense. Many poisonous foods and substances have a bitter flavour, so this is a protective mechanism as too bitter and we want to spit it out. Having bitter grouped at the back of the tongue as illustrated in my school days diagram would have been pointless, as by the time the offending substance was tasted it would have been half way to being ingested.
As with so many things in life, everyone tastes and experiences flavours so very differently. And it's not only the density of tastebuds, but also smell, sight, texture and memories that influence the sensations that tingle our tongues. Apparently about 10% of people have a high density of tastebuds which makes them 'supertasters', perfect for a job in a chocolate factory!
Taste is yet another of the body's amazing information channels. The tastebuds send signals to the brain telling it what to expect ie: sweet flavour means there's some carbohydrates on the way, and so the brain tells the body how to respond appropriately. There's an increase in salivary secretions, low levels of secretions in the stomach in anticipation and insulin is released to deal with the newly arrived sugar.
Also, the more we have of a flavour, the more we need to keep the same level of taste. So if you load your food with salt, you will gradually need more and more to produce the same level of flavour. Cutting out salt for a mere 2 weeks completely changes this. In the short term, food will taste quite bland, but once you reintroduce it again, you'll only need a tiny amount to get the salty taste you require.
This new tastebud knowledge got me thinking about food intolerance and having to cut things out of your diet. People have said to me "how can you manage without milk, or butter, or sticky toffee pudding? I don't think I could stop eating those things." Dairy certainly produces some wonderful flavours. I realised I don't really miss them. In fact I don't know if I'd even like them any more as my taste have definitely changed, particularly with sweet. I used to trough the puddings quite happily, the sweeter and gooier the better, but now deserts taste too sweet to me and I seem to prefer the natural flavours of fruit or cut right down on the sugar if making cakes. Plus, if taste includes memories and associations, I equate dairy with having migraines and feeling rotten, and I certainly don't miss that sensation!