Garlic and onions are essential ingredients in Korean cooking, loved for their bold, spicy flavors. Interestingly, how you prepare them can make a big difference in how much nutrition your body actually absorbs.

Garlic: Cooking Increases Antioxidants

When garlic is heated, its allicin and water-soluble vitamins B and C decrease. However, cooking actually boosts the activity of antioxidants and increases levels of polyphenols and flavonoids—compounds that help slow aging. Cooked garlic also tastes sweeter, making it easier to eat more of it.

Raw garlic, on the other hand, contains abundant hydrogen sulfide, which has been found to support heart health. There may be no such thing as odorless garlic—but if it doesn’t smell, it probably isn’t very nutritious. When garlic is chopped or crushed, the compound alliin reacts with the enzyme alliinase to form allicin—the substance responsible for garlic’s distinctive smell. Allicin is also garlic’s most potent compound, known to boost circulation, energize cells, and even enhance libido by stimulating hormone production.

To reduce garlic breath, tea leaves can help. Flavonoids in green tea neutralize garlic odor, while parsley leaves are also effective. Eating garlic with high-protein foods like meat, fish, eggs, cheese, or milk can further minimize its smell.

Onion: Sautéing Boosts Nutrient Absorption

For onions, it’s best not to cook them immediately after slicing. Let them sit at room temperature for 15–30 minutes first. Exposure to oxygen converts sulfur compounds—the source of onions’ pungency—into beneficial enzymes that boost metabolism and help prevent blood clots.

Sautéing onions in oil also enhances nutrient absorption. As moisture evaporates, the natural sugars become more concentrated, bringing out a stronger sweetness. Use healthy oils like olive or canola oil, which are resistant to oxidation. Cooked onions pair especially well with pork or beef. When the vitamin B1 in meat combines with allicin from onions, it forms allithiamine—a compound that supports energy production.

Even onion skins can be useful. They contain 30–40 times more flavonoids than the flesh, and can be used to make broth or tea. These flavonoids, including quercetin, have powerful antioxidant properties that help slow aging, prevent cancer, lower cholesterol, and regulate blood pressure.

If your eyes water while cutting onions, wet your knife first. The sulfur compounds that cause tears evaporate quickly but dissolve easily in water. Using a wet knife reduces the amount that escapes into the air—and helps keep your eyes from stinging.

Source: 헬스조선 (https://m.health.chosun.com/)