Most Landmark Theatres moviegoers already know that the flavorful taste of brewer's yeast is an alternative to less-healthy popcorn toppers like salt and butter. The Downer Theatre, 2589 N. Downer Ave., and the Oriental Theatre, 2230 N. Farwell Ave., included shakers of brewer's yeast -- also called "nutritional yeast" -- in their condiment collections since 1988.

"I remember several people saying that it was something we picked up from theaters in California," says John Dahlman, manager of the Downer Theatre. "I love brewer's yeast on popcorn, which I have eaten practically every day for 17 years."

Originally, according to Dahlman, the Landmark Theatres gave out lots of popcorn-with-brewer's-yeast samples because customers were unsure of it, but these days, they rarely give away freebies because so many people know it by name.

"I recall a customer once getting a ticket refund when they found out we were out of the yeast," says Dahlman.

Landmark Theatres purchase their nutritional yeast from Beans and Barley, 1901 E. North Ave. Beans sells two kinds of yeast: The Lewis Lab brand sells for $14.79 per pound, and Red Star Yeast goes for $8.15 per pound. The Red Star brand -- made in Milwaukee -- is available in smaller amounts.

Brewer's yeast is a deactivated yeast that's also a nutritional supplement used in recipes and as a condiment. It's low in fat and sodium, and usually fortified with B vitamins. Many people use it, especially vegans, as an alternative to Parmesan cheese as well as a popcorn topping.

Although the terms "brewer's yeast" and "nutritional yeast" are used interchangeably, they're not exactly the same. Nutritional yeast is any yeast grown for the specific purpose of being a food supplement, and is enhanced for better flavor because brewer's yeast has more of a bitter taste.

Nutritional yeast usually comes in the form of flakes or powder (but tablets are also available) and has a slightly nutty, cheesy flavor. It works well in a salt or red pepper shaker for easy access.

Pat Sturgis, co-owner of Beans & Barley, has eaten nutritional yeast on popcorn for 30 years. "My wife even carries a little shaker in her purse," he says.

Aside from popcorn, Sturgis puts nutritional yeast on brown rice, cottage cheese and his cat's food.

"I don't really know if this is a fable or not, but I have heard it helps cats resist fleas in flea season," he says.

Stacy LaPoint, president and co-owner of Companion Natural Pet Food, confirms that brewer's yeast works as a flea repellent for dogs and cats.

"Brewer's yeast contains all the B vitamins, Niacin and free-form amino acids which is added nutrition that could boost the immune system, then making it easier for an animal to naturally resist parasitic infestations," says LaPoint.

Brewer's yeast might also help people who are having difficulty sleeping, because it contains Niacin and Vitamin B6, which work together to create serotonin that is essential for restful sleep. It may also aid with diabetes, hypoglycemia, high cholesterol, eczema, nervousness, fatigue and constipation.

"Nutritional yeast is a condiment you should experiment with," says Sturgis.