The mere mention of food additives may conjure images of mysterious powders and potions being sprinkled, stirred and shaken into the foods you and your family eat every day. Read the ingredient labels on just about any packaged food and you may wonder why so many of these scientific-sounding substances need to be there — and more important, whether they’re OK for your health.

Food additives include a variety of substances that are categorized into groups such as flavors, colors, texturizing and stabilizing agents, sweeteners, emulsifiers and preservatives. These additives improve the taste or texture of a food or make it last longer on the shelf, for example.

Some packaged foods and drinks are heat treated to keep them safe to eat. The heat can cause unwanted changes — it can make a beverage separate or turn a vegetable soggy. An additive can provide viscosity to a food that has changed in texture or lend some extra crunch to a vegetable that has softened.

Additives might extend a food’s shelf life or make it more palatable — but what about your shelf life? “You can say with a great deal of certainly that there just is no evidence that food additives are harmful,” says David Levitsky, PhD, professor of nutrition and psychology at Cornell University.

Before manufacturers can use additives, they undergo extensive testing, explains Eric Decker, PhD, professor in the department of food science at the University of Massachusetts at Amherst. “The amount that is consumed is so low that it is not a risk,” he says. “The biggest concern is not food additives, but diets that lead to health issues such as obesity. These are way more dangerous than anything you will see from food additives.”

Common additives and what they do

Carrageenan: This is a natural compound that comes from algae. It’s often used as a thickening agent in ice cream. “Cheaper ice cream has less fat in it, and if you didn't have carrageenan, you would need to use more fat to get the thickness you want,” says Levitksy. Carrageenan acts as a fiber in the body, he notes.

Related: The Truth About Carrageenan

Calcium carbonate: This naturally occurring compound (used as a calcium source in many calcium supplements) is added to flours as a dough conditioner. It also functions as an anti-caking agent, says Gerald P. Kelly, senior technical consultant at UL Verification Services, Inc. in Canton, Massachusetts. Manufacturers sometimes add it to high-end salts to prevent clumping. This additive also controls the acidity of a product and may be used as a source of calcium in various foods, says Decker.

Carboxymethylcellulose: Derived from cellulose, a form of carbohydrate, this is used as a stabilizer and thickening agent in food products such as puddings. It’s also is added to provide fiber. “If a product wants to make a claim that something is high in fiber, they may use this,” Kelly explains.

Calcium chloride: A mineral salt, this is added to processed vegetables to make them firm. It’s a popular additive for pickles since it keeps them nice and crisp. “When vegetables are cooked at a high temperature, they tend to get mushy, so this may be used in the cooking water to give vegetables that are being canned a little more texture,” Decker says.

Guar gum: Made from extracts of guar seeds, this thickener changes the properties of foods such as frozen yogurt, enhancing the taste and what it feels like in your mouth, says Levitsky. “You notice the difference in texture when you dip your spoon into it and the food clings to it,” he says. Guar gum is added to ice creams and some cheese products.

Sodium acid pyrophosphate: This combination of phosphoric acid (derived from phosphate rock) and sodium hydroxide (also know as lye) or sodium carbonate (also known as soda ash) acts as a leavening agent in cookies. It provides a little bit of volume, but not has much as you would get using yeast, Kelly explains.

Potassium sorbate and sodium benzoate: A prepared fruit or potato salad purchased at the supermarket is likely to contain one of these salts, says Kelly. They increase shelf life by preventing the growth of bacteria, mold and yeast.

To reduce your additive intake

If you’re concerned about eating too much of any particular additive, eat a varied diet, suggests Decker. “You would have to eat a tremendous amount of an additive before it would be a problem,” he says. “If you eat different kinds of foods, you’re less likely to consume a lot of one additive.”

To cut down on additives altogether, purchase organic packaged foods or cook from scratch. Also look for foods grown locally. When food is grown nearby, the shelf life doesn’t need to be extended, so it’s less likely that the food will contain additives.

Related: Should You Stop Eating Canned Tomatoes?