The First Leaves from the Garden
Fellow gardeners, as spring turns to summer, lettuce is probably the first crop in the garden to offer up a harvest. Not long after you sow the seeds, plump leaves begin to rise. If you pick them one at a time from the outside in, a single plant can go a surprisingly long way at the table. You rinse a freshly picked leaf under running water, top it with a spoonful of rice, and fold it into ssam, a hand-held lettuce wrap. That scene has graced Korean summer tables for generations.
Few crops ask so little of the gardener and give back so much. Once lettuce settles in, the more you pick, the more it grows back, so it becomes a dependable member of the household all season long. How did people in the past see this everyday green we keep so close at hand? Let's open the Dongui Bogam (Treasured Mirror of Eastern Medicine), Korea's classic medical encyclopedia from the early 1600s, and find out.
What the Dongui Bogam Says
The Dongui Bogam lists lettuce under its medicinal name, wageo (萵苣), and describes its nature as cool. One passage goes further and calls it cold, so the text clearly sees lettuce as something that cools the body's heat. It records the flavor as bitter and says the plant is mildly toxic. To picture that sharpness, think of the milky white sap that beads up when you cut a lettuce stem.
As for its benefits, the text says lettuce strengthens the sinews and bones, benefits the five organs, and loosens energy that has become stuck in the chest. It also notes that lettuce opens the body's meridians, whitens the teeth, sharpens the mind, and lessens the need for sleep. It even says lettuce can treat snakebites.
The Dongui Bogam also leaves a word of caution. Quoting the Introduction to Medicine (Yixue Rumen, a Ming-dynasty Chinese text), it notes that people eat lettuce regularly as a vegetable, but those who suffer from cold conditions may find it chills the belly. It adds that lettuce won't do anyone serious harm. Read this way, the advice is not to fear lettuce, but to eat it with some care if you tend to run cold. The text also has a separate entry for baekgeo (白苣), or white lettuce. Citing the Bencao, a classic Chinese materia medica, it says white lettuce shares the same nature, flavor, and benefits as wageo and looks much like it. The difference is that white lettuce has fine white hairs.
How It Compares with Modern Nutrition
The Dongui Bogam saw lettuce as cooling and able to clear stuck energy in the chest. That isn't far from how we think of it today, as a watery, low-calorie leafy green. If you've ever lost your appetite in the thick of summer heat, you may know how a plate of lettuce wraps can leave you feeling refreshed and settled. The old text's "cold nature" and "opening of the chest" fit naturally with that cool, refreshing feeling. Like other leafy greens, lettuce supplies water and vitamins, so it's easy to see where the old idea that it's good for the skin might come from.
The claim that lettuce lessens sleep deserves a closer look, because it sits oddly with how drowsy lettuce is said to make people. The Dongui Bogam seems to point one way, but Korean tradition has long held that eating lettuce makes you sleepy. The usual explanation is the calming effect of compounds such as lactucin, found in the milky sap of the stem. It's fun to set the old texts, folk tradition, and modern chemistry side by side. These comparisons simply layer a traditional view over general knowledge, though. They are no basis for claiming that lettuce treats anything.
From Garden to Table
Lettuce is at its best raw. Use it to wrap rice as ssam or toss it into salads. When the plants are producing more than you can keep up with, try blanching the leaves lightly and dressing them as muchim, a seasoned Korean side dish, for a change of pace. In the past, people even collected the white sap from the stem separately for medicinal use.
Keep one thing in mind when you eat it. As the Dongui Bogam advises, lettuce is cooling by nature. If you have a weak stomach, tend to feel cold, or are prone to loose stools, it's best to go easy. Because of its reputation for causing drowsiness, avoid eating a lot of it before driving. On the other hand, a few lettuce wraps before bed may be a bit of old wisdom worth trying for a good night's sleep.
Add the view of an old medical classic to a leaf of lettuce you grew yourself, and that familiar green may start to feel a little new.
