SAN DIEGO (CN) – Nestle and California Pizza Kitchen are "deliberately poisoning their consumers" with "trans fat pizzas" containing partially hydrogenated vegetable oil, a "toxic carcinogen," a woman claims in a $5 million class action.

Katie Simpson sued California Pizza Kitchen and Nestle, whose store-bought pizza brands include California Pizza Kitchen, DiGiornos and Stouffer's, in Federal Court.

Simpson does not claim she was forced to eat Nestle's pizzas, but says she "repeatedly purchased Nestle trans fat pizzas for personal and household consumption."

She claims that Nestle squeezes healthier pizzas off supermarket shelves by using the low-cost food additive, partially hydrogenated vegetable oil, allowing it to increase its market share.

"Artificial trans fat is a toxic carcinogen for which there are many safe and commercially acceptable substitutes," Simpson says. She claims it has been shown to cause, or contribute to, heart disease, type-2 diabetes, breast, prostrate and colorectal cancer, Alzheimer's disease and or cognitive decline.

"Although there are safe, low-cost, and commercially acceptable alternatives to trans fat, including those used in competing brands and even in a few Nestle and CPK [California Pizza Kitchen] products, defendants unfairly elect not to use those substitutes in the Nestle trans fat pizzas in order to increase profit at the expense of consumer health," the 16-page complaint states.

Partially hydrogenated vegetable oil was invented in 1901, and patented by German chemist Wilhelm Normann, according to the complaint.

"Artificial trans fat is manufactured via an industrial process called partial hydrogenation, in which hydrogen atoms are added to normal vegetable oil by heating the oil to temperatures above 400 degrees Fahrenheit in the presence of ion donor catalyst metals such as rhodium, ruthenium, and nickel. The resulting product is known as partially hydrogenated vegetable oil, or PHVO, which is the main source of trans fat in the American diet and used in dangerous quantities in the Nestle trans fat pizzas," the complaint states.

Due to its low cost and long shelf life, the additive was marketed originally as a "'wonder product'" and used in many processed foods.

But in recent years scientists have determined that trans fat is unhealthy, and many countries have banned or limited its use, including Denmark, Austria, Switzerland, Brazil, Argentina, Chile and South Africa.

California was the first state to ban artificial trans fat, in 88,000 restaurants, and has limited the amount of trans fat used in foods offered on school menus, Simpson says.

New York City banned trans fat in 20,000 restaurants in 2006, and Philadelphia, Stamford, Conn., and Montgomery County, Md. followed suit.

"Now, given its toxic properties few food companies continue to use PHVO. Defendants, however, have decided not to follow their more responsible peers and cease using PHVO, instead placing profits over public health and deliberately poisoning their consumers," the complaint states.

Simpson claims Nestle's profits are "far outweighed by the gravity of the serious health harm imposed on consumers." She claims this "unfair, immoral behavior" limits shelf space of competitors who make trans fat-free pizzas.

States are also burdened by sick Americans who seek treatment through Medicare and Medicaid programs after eating trans fat pizza, Simpson claims.

She adds: "Plaintiff lost money as a result of defendants' conduct described herein in that she purchased products that, because they were detrimental to her health, were unfairly offered for sale in violation of California law. Had defendants not violated the law, plaintiff would not have been able to purchase the Nestle trans fat pizzas, or would have only been able to purchase Nestle and CPK pizzas containing safe alternatives to PHVO and trans fat."

She seeks restitution, disgorgement, a cease and desist order for abatement of nuisance, corrective advertising and damages for unfair competition.

She is represented by Gregory Weston.

Nestle did not immediately respond to a request for comment.