Autoimmune Thyroid Disease

An Unfortunate and Lengthy Adventure in Misdiagnosis

Why kids don't eat their greens

with 5 comments

Choking on Cucumber

My Dad experiences certain tastes differently. So does my partner J. They can both taste something that I can’t in cucumbers and melons. Cucumbers and melons have a similar mild, weird taste to me, which I don’t find particularly unpleasant or indeed pleasant. By contrast my Dad is completely repulsed by cucumber and can just about manage the occasional slice of honeydew melon. He says these foods “taste like petroleum.” My partner J. reports something slightly different. To him, melons and cucumber taste almost, but not quite, like sick. He can’t even bear to eat things that cucumber has touched. I can’t find much information on the net about this particular aversion, but I believe it might be down to a chemical called cucurbitacin, an alkaloid which can cause severe stomach upset if ingested in a large enough quantity. There is certainly an evolutionary advantage in being able to taste this chemical, since tasters and non-tasters alike are equally susceptible to its effects.

Bitter Almonds

Cyanide is another interesting chemical that some of us can or cannot smell and taste. It is bitter in flavour and has an almond-like odour. About forty percent of the population can’t smell cyanide at all because they lack the gene to do so. Certain bacteria, fungi, and algae produce cyanide compounds that serve as a defence against being eaten by animals. Cassava, many fruit pits, apricot kernels, and bitter almonds all contain a cyanide compound known as laetrile or amygdalin that has anti-cancer properties. Whilst in this respect a small amount of cyanide can be beneficial, too much can clearly kill, so being able to smell and taste the distinctive “marzipan” bitter almond flavour of cyanide gives one a very useful evolutionary advantage when choosing one’s next meal. I can smell and taste cyanide compounds, but not as well as J. who protests vociferously if I mix apricot kernels in with the rest of our snack box of nuts. Whilst I can tolerate the mild bitterness (and occasional vile-tasting cyanide-bomb) of the apricot kernels and almonds, J. tastes a cyanide-bomb every time.

Why Don’t I Like Salads?

J. and I are also “supertasters.” A supertaster can taste two chemicals, phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP). About 25% of people taste these chemicals as a very bitter taste. Another 50% can taste them mildly, and the last 25% can’t taste them at all. Supertasters can taste a bitter substance in the following foods:

  • Green tea and to a lesser extent black tea
  • Black Coffee
  • Grapefruit
  • Undercooked or raw cruciferous vegetables such as cabbage, broccoli, Brussels sprouts
  • Peppers and chili peppers
  • Some salad greens (especially rocket)
  • Spinach
  • Strong cheeses
  • Dark chocolate
  • Dry wines and beer
  • Tonic water
  • Olives
  • Soy products

Supertasters can also taste sweetness as being sweeter than a typical taster, and sourness in fruits as being sourer. Any strong flavour or odour like tomatoes, cured meat, yeast, cheese, game, or fish is also deeply intensified. Says one particularly badly afflicted supertaster, “If it came from the ocean, I don’t eat it.”

Picky Eating

It’s a well-known universal truth that children hate eating their greens, and not without foundation. I can taste the bitterness in PTU/PROP containing foods; it’s why as a child and teenager I disliked tea, coffee, beer and wine, salads, all of the green vegetables listed, and I found olives and grapefruit downright revolting. As a vegetarian teenager I found soy products to be beyond disgusting and pleaded with my mother for her not to buy them for me.

But there was more to my dislike of foods than bitter tastes. I also disliked fruit intensely, yet curiously I never had any problems eating a sugar-loaded breakfast cereal. Bread (which contains soy and yeast), was only made edible with the addition of jam (seedless, the seeds were chewy and bitter); I refused the crusts because they tasted burnt, and wholemeal was completely inedible. I always gagged at the sick-smell and taste of both meat pies and cheese and tomato lasagna.

Looking back, it seems my Mum was always desperately trying to get me to eat things that I found revolting, from green vegetables to battered fish, which made me want to throw up. She thought I was some sort of child anorexic: I wasn’t, I just couldn’t stomach the taste, smell and texture of certain foods. The only thing I really liked the taste of during my childhood was fresh whole milk, and I was in a constant battle to be supplied that instead of UHT skimmed, which tasted putrid to me. It was around the time that “Maggie Thatcher the milk snatcher” removed my free milk from the school menu when I reached the age of seven, that my mother began to get very worried about my weight because there was so little that I actually wanted to eat. She went to the extent of putting tabs on me at school. All the teachers and the dinner ladies monitored what I ate, so I was forced to eat my revolting cardboard, yeast and burnt flavoured sandwiches. Why not give me school dinners? Ah, no, I was too picky for that, best not to even try!

Mum has always (rather unjustly) believed that I am in some way anorexic or picky and obsessed with food and sees my teenaged vegetarianism and my current interest in nutrition as an extension of this. I see things rather differently; for most of my life I have been completely disinterested in food and had absolutely no understanding of its impact on my body. Only recently have I come to discover that food is very interesting stuff and I am now the exact opposite of the anorexic I never was: I am busy trying to nourish myself in order to cure my chronic illnesses.

I think that the big clue in my relationship with my Mum over food, is that one day my family all sat down to a dessert of grapefruit, and my Mum was the only one who could actually eat it. We all declared it bitter, but I actually reacted very violently, gagging and spitting mine out and declaring it (rather precociously) to taste like cat’s piss. If only we had known about supertasting, maybe my childhood mealtimes would have been less of a battleground.

I’ve since “acquired” a taste for many of the classic supertaster foods, though I still find that green tea tastes like washing up liquid, soy is still manky flavoured cardboard, and grapefruit tastes like cat piss. Whether I am a full supertaster or one of the 50% majority of people who experience a mild bitterness, I don’t know, but I’m guessing I’m a full supertaster. What I do know is that J. is far more sensitive to bitterness in vegetables than me, though like me, he too has acquired a taste for alcohol, olives, dark chocolate, black coffee and strong cheeses, and he has always liked tomatoes while I don’t. I am still not a big alcohol drinker, and I can only take coffee and tea in small doses. I’m still iffy about game, but quite happy to eat cured meat, and while most people regard fish as a subtle taste, I find it quite strong and alien. I find most fish to be pretty unpleasant in taste (earthy, bitter, fishy) while J. does not, though I am happy enough eating very fresh shellfish and crustaceans. Oysters and seaweed taste vilely of rock-pools, but since oysters are very small and nutritionally worth the effort I will eat them, the rock-pool taste being largely neutralised by a bit of vinegar.

Evolution in Action?

I wonder what the genetic advantage is in tasting PROP and PTC? There must be one for the gene to be so widespread. Most of the supertaster articles you will find on the net or in the media describe what a terrible disadvantage such people have; supertaster children don’t eat their greens and are picky eaters (with misleading hints towards “anorexia” in spite of the fact that greens are typically low-calorie foods), and howls of dismay that supertasters don’t get enough of the anti-cancer chemotherapeutic phytochemicals and “wonderful” bioflavinoids found in such foods.

Or are they really that great? After starting Atkins, I became a dedicated salad-eater, but it was with some relief that I gave up eating regular salads last year when I sat down and took a look at what vitamins salad greens actually contain. I found that they don’t contain very much of anything apart from a tiny bit of folic acid and a bit of vitamin K, and most of them being destroyed by the “modified atmosphere” nitrogen packaging they are shipped in. Fortunately I can get both of these vitamins from elsewhere without having to endure the horrible bitterness of all red and dark green leaves. Brassicas are a very useful source of vitamin C and folic acid, and maybe a few carotinoids and chemotherapeutic agents, but unless you are planning to eat at least half a dozen cups a day (I dare you to try), they are pretty much useless for anything else.

That’s why My Hair is Falling Out!

Edible plants develop poisons over time when they are eaten due to natural selection. Poisonous and bitter-tasting plants are selectively rejected by animals that prefer sweeter shoots, with the consequence that their population increases. I also know that this very same group of bitter crucifers, greens, and soy foods contain goitrogens; chemicals that disrupt and depress thyroid function. PROP is in and of itself a goitrogen used to treat hyperthyroidism. In green vegetables, about a third of these chemicals are neutralised by cooking or fermenting, in soy they are extremely difficult to neutralise. Thyroid inhibitors are particularly damaging for children, those classic “picky eaters,” as they can lead to delayed development, lowered intelligence, and shortness of stature with normal or overweight.

Whilst we almost always cook brassicas and crucifers these days to reduce the PROP, PTC and other goiterogen content, the bitter taste supertasters detect may have helped our raw-vegetation-eating ancestors distinguish poisonous, thyroid-damaging plants from the rest and avoid or regulate their intake in order to gain the benefits of eating them without also gaining the disadvantages. So perhaps the next time you tell your kids to eat their greens and they refuse, you should ask yourself if they know better than you?

Notes from October 2007

It’s actually quite exciting to read this post back today, as it demonstrates how in February 2006 my sights had finally rounded on vegetables as a cause of my problems. I knew I was on the verge of a major breakthrough, as I’d realised I was reacting to some vegetables – like broccoli.


Written by alienrobotgirl

5 February, 2006 at 10:43 pm

Posted in My History

5 Responses

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  1. […] are a veritable religion), had a rather violent negative reaction to the contents of “why kids don’t eat their greens“, which seemed quite an innocent article to me when I wrote it. I’m glad it’s […]

  2. […] veggies primarily because they taste like absolute crap,” he says. It sounds like Rob is a supertaster. I understand Rob, as only other supertasters can understand! Around 25% of people can taste a […]

  3. […] I ate my lunch very slowly, and I hated the taste of most food. It turns out that I’m a supertaster, and it’s really not my fault: food really does taste bad. Joan Breakey’s research into […]

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