We recently ran an item about strange food reactions (what happens to urine after you eat red beets or asparagus, for example). A reader commented that we’d missed out on a personal favorite: the lingering sweetness that eating an artichoke imparts to the senses.
Try it. Eat a fresh, steamed artichoke and then take a sip of water. The water will taste sweet. (It doesn’t work with pickled artichoke hearts.)
What’s the science behind this, we wondered.
Searching the biomedical databases, we found a landmark 1972 paper on the topic, published in the journal Science. Two chemicals in artichokes were implicated in the study: cholorgenic acid and cynarin. The scientists assessed how sweet water tasted after: a) eating artichoke extract; b) consuming cynarin; c) consuming cholorigenic acid. The artichoke extract made the water sweeter than either of the two chemicals alone.
Of the two identified chemicals, cynarin seems to be the one most studied. It stimulates bile production and is a diuretic, apparently. Back in the 1970s, a few medical studies explored its potential as a cholesterol-lowering agent: I found one from 1975 that reported positive results in a group of 30 patients compared with 30 controls, and another from 1977, of 17 patients with abnormally high cholesterol due to a family condition, that found it didn’t help at all. I saw articles exploring cynarin as a potential immunosuppresant, or artichoke extract as a remedy for irritable bowel syndrome, and another exploring the therapeutic effects of administering cynarin up the rectum. (The literature also revealed an “exceptionally rare case” of contact dermatitis caused by touching an artichoke.)
These kinds of findings may explain why artichoke extracts are for sale on all kinds of medicinal/herbal websites. Me, I’d rather eat artichokes.
Back to the taste effect. To find out more, I e-mailed one of the original authors on the 1972 paper, Linda M. Bartoshuk, Bushnell Professor at the University of Florida Smell and Taste Center. Here’s what she had to say:
“I have not worked on this recently, but the most likely explanation I know is that cynarin inhibits some part of the sweet receptor. Washing off the cynarin releases that inhibition, sending a message to the brain along the fibers that mediate sweet taste. The artichoke effect is one of a large number of similar effects: Removing a stimulus triggers taste. We call these effects 'water tastes.' "
Bartoshuk went on to add, interestingly, that right now scientists are arguing about how many sweetness receptors there are on our tongues. “The current lore is that there is only one sweet receptor,” she says. “The problem [with] this explanation is that it requires that all sweets taste alike. Obviously this is not true.
“The believers argue that some sweets taste different because of the addition of another taste (e.g., bitter taste of saccharin). But those of us who do not taste some of the off tastes of sweeteners ( I am one of them) know that all sweets are not alike. For example, to me the sweetness of aspartame is very unlike the sweetness of sucrose.” (Sucrose is regular old table sugar, the stuff we get from sugar cane and sugar beets.)
True. I find aspartame cloying, Splenda much less so. A friend, on the other hand, noticed instantly (and was outraged) when I tried to pass off a Splenda-sweetened Diet Coke as regular old Diet Coke. I just had a stevia-sweetened drink and I didn’t care for it, though to be fair, that might have more to do with the weird not-quite-orange flavoring.
There’s a lot, it’s clear, behind even the simplest of taste sensations. Here's a Q-and-A with Bartoshuk that discusses a few of the others.
--Rosie Mestel / Los Angeles Times
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