The keepers of the sprout

16 December 2006

So what about Weckx’s boldest claim: that boiling sprouts once, in the British style, leaves them toxic to humans, or at least unbearably bitter? Paul Breslin, an American geneticist, offers a cautious endorsement. He has studied compounds known as glucosinolates found in sprouts and vegetables like broccoli. These compounds are toxic to people with thyroid problems (though they appear to help ward off cancer in healthy people). They are bitter-tasting and they are broken down by cooking, he confirms. However, there is a catch. In a development that offers the science-minded family the promise of loud disputes this Christmas, geneticists have found that those same compounds do not taste bitter to everybody. In crude terms, about 30 per cent of the population have a genetic quirk that leaves them unable to pick up the bitter taste of glucosinolates. To use more technical terms, Brussels sprouts taste less bitter to people who are ‘homozygous for the AVI haplotype of the hTAS2R38 gene’ — a line you may care to remember for use around the dining table.

This is potentially devastating news for sprout lovers. What if we are merely insensitive freaks, and not brave at all? Reached by telephone at the Monell Chemical Senses Centre in Philadelphia, Dr Breslin warns against concluding that sprout-loving is simply a question of genetics. ‘Tasting bitterness is not the same thing as liking or disliking vegetables,’ he says. Grown-ups routinely learn to love bitter things, especially when they carry social cachet, like coffee or beer.

Yet under prodding, Dr Breslin admits that he is in the 30 per cent of the population who cannot taste bitter glucosinolates. And yes, he loves sprouts. ‘My wife can’t stand them, so when I prepare them, I am on my own.’ Which sounds like the makings of an excellent British-style Christmas.

David Rennie is a contributing editor of The Spectator.