What’s that unfamiliar terminology on your nutrition label? Could it be a potential carcinogen? A hidden vitamin? Actually, ingredients run the gamut. And erring on the side of caution by avoiding multisyllabic, chemical-sounding words doesn’t always work, because some scary-sounding ingredients are in fact healthy. Here are some common terms to watch for.

Saturated fats, which are listed in the fats section, are found primarily in animal products, including whole milk, butter, cheese, red meat, and ice cream, as well as in coconut oil, coconut milk, and palm oil. They’re troublesome because they can increase LDL, the bad kind of cholesterol.

Trans fats, found in most margarines and many fast foods and commercially baked products, may be even more unhealthy than saturated fats because they may boost LDL cholesterol and triglycerides (another form of blood fat), and they may make blood platelets stickier than usual, encouraging the formation of clots. A high intake of trans fats has been associated with an increased risk of heart disease. By 2006 the FDA will require that food makers list trans fats on labels under Total Fat. Until then you can find them listed in the ingredients section under assumed names, such as “partially hydrogenated vegetable oil” and “vegetable shortening.”

High-fructose corn syrup is found in juices, cookies, even pasta sauce. This ubiquitous sweetener is implicated in America’s obesity problem and in the worldwide diabetes epidemic because, like other sugars, it raises blood sugar dramatically and is high in calories that don’t make you feel full. It’s best to limit consumption of products with added sugar.

Chemicals with names like “potassium metabisulfite” and “calcium chloride” can send a chill down a healthy eater’s spine. Many of these oddly named substances are preservatives, but some of them have health benefits. These agents usually occupy the fifth or sixth position on an ingredients list, so they’re not present in large amounts. But if you’re sensitive to sulfites, a type of preservative, even small amounts may cause an allergic reaction. Calcium chloride, often used to maintain the shape of canned tomatoes, is actually an added source of dietary calcium.

Propellants, used in vegetable cooking sprays, carbonated beverages, and sprayable whipped cream, are a far cry from the rocket propellants used by NASA. Nutritionists consider them safe. Cooking sprays, in fact, are a good way to reduce fat intake. Products like Pam contain little or no fat and single-digit calories. In contrast, a tablespoon of oil, margarine, or butter contains 11 to 14 grams of fat and 100 or more calories.