My own first experiences with cross-cultural food rules came from my Italian in-laws. In the early years of my marriage, I'd sit at my mother-in-law's elegant table in the handsome Veneto town of Portogruaro and try to absorb her nuggets of food wisdom without blinking. Cucumbers, as mentioned, should be avoided, since they are well known to produce indigestion. Red peppers and eggplant are heavy, and act like daggers to the liver. Drafts, put simply, are lethal—almost any illness can be traced back to exposure to a sudden draft, and a cold breeze blowing across the belly causes the digestive apparatus to freeze up like an engine out of oil.
As I settled into Italian domestic life, this all became second nature. I may not have subscribed to the draft theory of mortality, but I dutifully covered my children's bellies and barred cucumbers from the communal salad bowl. Yet I found myself sensitized to this issue of international food theories. I began to ferret them out from friends, passing acquaintances, and particularly from spouses in cross-cultural marriages, a situation where people are most likely to butt up against each other's culinary preconceptions.
Like any good collector, I like to break my resulting finds down into categories.
The timing of food is a recurrent theme. The Portuguese, for example, insist that you must never eat oranges at night. There's even a lyrical saying: "Laranja de manhã é ouro/Ao meio dia é prata/E á noite mata," which, roughly translated, means "oranges are gold in the morning, silver at noon, and killers at night." A Jamaican client tells me that goat soup is best eaten after sunset (presumably because of its aphrodisiac properties); a Cape Verdean nurse counsels against eating sweet potatoes after dark; and Italians, of course, find milk distasteful once morning has come and gone, which explains the precipitous drop in cappuccino consumption after 11 a.m.
Concerns about temperature are another constant. A friend's Taiwanese husband insists one should never drink anything cold with a meal, because it congeals the oils in the food and blocks up your pipes. Another friend's French wife skips the congealed oil explanation but is just as certain that ice water paralyzes the stomach and halts digestion. In fact, Americans may be the only people on the planet who think nothing of downing enormous trash-can-sized cups of ice and freezing liquid at every opportunity. Who knows how blocked up our communal pipes have become?
Sometimes the hot and cold aspect is more metaphorical. A Chinese friend could fill a notebook with her mother's admonitions on cold food and hot food. To paraphrase: fruits and green vegetables that grow close to the earth and absorb humidity—watermelon, napa cabbage, green mung beans—have a cold nature. Red azuki beans, hot pepper, red meat, dates, and an endless list of other reddish foods have a hot nature. If you're coughing, or recovering from a cold, avoid cold foods like the plague. If you're a woman and have just given birth, hot foods will heal your female organs. Cold foods may stop a nosebleed; hot foods will give you pimples. My friend's mother can go on like this all day.