SUNDAY July 27, 2008 (foodconsumer.org) -- California on Friday became the first state to ban the use of artificial trans fat also known as partially hydrogenated vegetable oils, long linked to clogging of arteries, in all restaurants and other food establishments in the state.

Gov. Arnold Schwarzenegger signed a bill that prohibits restaurants from using trans fat in any form of fat including oil, margarine and shortening. The bill AB97 was introduced by Assembly member Tony Mendoza (D-Norwalk).

Under the new law, the use of trans fat in all California restaurants will be phased out by Jan 1, 2010 in all foods except for baked foods which will be free of trans fat by Jan 1, 2011. Violations of this law lead to fines ranging from $25 to $1,000.

Does this law solve the problem associated with trans fat in California? The law does not seem to affect packaged foods which may contain trans fat. There are some other issues about the substance that has been linked to coronary heart disease and other chronic disease such as diabetes.  

Below are some common questions and answers foodconsumer.org published early and cited here for those who are interested in learning more about trans fat.

What are trans fat?

Trans fat is the common term for partially hydrogenated vegetable oils that contain trans fatty acids. Natural liquid vegetable oils are transformed into solid or semi-solid trans fat in a chemical process known as partial hydrogenation - adding hydrogen atoms to the natural unsaturated fatty acids in vegetable oils.

Why does the industry use trans fat?

Trans fat is used widely in processed food mainly for a longer shelf-life and desirable palatability including texture and mouth feel.  Sometimes trans fat also renders a particular flavor profile. Trans fat is commonly used in fries and baked goods.   Solid saturated fat from animal sources may have similar functionalities. In early days, the industry actually used saturated fat such as beef tallow. Later, saturated fat was found to raise low density lipoprotein or LDL or bad cholesterol, increasing risk of coronary heart disease. Because of this, the industry shifted to using trans fats, thinking that trans fats would not have the adverse effects as saturated fat does.  

What can tran fat do to damage human health ?

In fact, trans fat is worse than saturated fat, the former can raise not only bad cholesterol, but also kick out the high density lipoprotein or HDL or good cholesterol while the latter only raises bad cholesterol. Many randomized and controlled dietary trials have already found that consumption of trans-fat can more than raise bad cholesterol. It can promote inflammation that is implicated in many chronic diseases such as heart disease, heart attacks, diabetes   and other chronic diseases such as infertility. Recent studies have shown trans fat may also hurt learning ability and memory.

Harvard epidemiologists and nutritionists estimated that trans fat is involved in as many as 100,000 people in the United States each year.  

Is there any safety threshold for trans fat?

There is no safety threshold for trans fat, meaning intake of trans fat in any amount may have an adverse effect. Nutritionists and epidemiologists at Harvard School of Public School recommend that consumers completely avoid intake of trans fat or avoid as much as they can.

How does the government say about the safety on trans fat?

The Food and Drug Administration sometimes if not always make statements like 'trans fat like saturated fat increases levels of bad cholesterol.' It does not point out other risks as often. But the FDA never says consumption of trans fat is safe as evidence suggest otherwise.

How much trans fat Americans consume each year?

Consumers in the US eat trans-fat equivalent to 2 to 3 percent of total daily calories. This translates into 4 to 6 grams each day. In a year, an average American may consume about 5 pounds of trans fat.

Does the FDA recommend consumers avoid trans fat?

The FDA suggests consumers should NOT completely avoid trans fat as complete avoidance of trans fat could restrict consumers' selection of foods, potentially causing nutritional imbalance. At this time, the government suggests consumers limit their daily intake of trans fat below 1 percent of total calories, which is 2 grams of trans fat per day. But again, that recommendation does not mean one percent is safe. Harvard scientists say trans fats do nothing good except for energy and they recommend consumers should completely avoid trans fat.

Did the government ban use of trans fat in processed food?

No.  Governments, federal nor state, have not ever banned use of trans fat in packed food or food prepared at restaurants. New York City just proposed on Sept 26, 2006 to phase out use of trans fat in restaurants. In six months, restaurants should use, partially hydrogenated oils, margarine and shortening without trans fat for frying and spreads. But still 0.5 grams per serving of trans fat are allowed.   The city law takes effect on Sunday July 1, 2007.   By July 1, 2008, no food prepared by restaurants should contain trans fats. That means trans fat in restaurant-prepared foods need to be absolutely zero.

A s of January 1, 2006, the FDA requires the food industry, not the restaurant industry, label trans fat on food packaging, but allow the food manufacturers to claim “trans fat: zero” when less than 0.5 grams of trans fat per serving is present in a food.

Does 'zero trans fat' on a label mean the food absolutely contain no trans fat?

The FDA allows food processors to claim "zero trans fat" on the label of a food if the food contains a level of trans fat that is below 0.5 gram per serving.

How could consumers know a food contains trans fat or not?

Consumers should read both the label and the ingredient list. Claims like zero trans fat can be confusing and misleading. If consumers are told "trans fat: 0", they need to go through the ingredient list to see if there is any partially hydrogenated vegetable oil or items that contain trans fat. Sometimes, trans fat may be present in other ingredients such shortening and margarine. For vegetable oils, the producer may not list trans fat, but try to add up all types of fat including saturated fat, monounsaturated fat and polyunsaturated fat to see if the total matches the total (serving) size (usually 15 grams). If both are different, then there is likely some trans fat.

Is a food with no artificial trans fat added absolutely free of trans fat?

In addition to the industrially produced trans fat, a food may contain trans fats from other sources. Meat and milk from ruminant animals contain small amounts of naturally occurring trans fat. Trans fats can be converted from natural vegetable oils at high temperatures. That is why natural vegetable oils being refined may contain trans fat. A food with polyunsaturated fat may produce some trans fat after it is subject to thermal treatment. For instance, home cooking can also result in some trans fat if high heat is used to cook vegetable oils such as in a frying process.   The label may not tell consumers everything contained in a food. For instance, contaminants if not too much introduced during the processing are not labeled.

What are the major foods for trans fat?

Major food sources of trans fat for American adults include cakes, cookies, crackers, pies, bread (40%), animal products (21%), margarine (17%), fried potatoes (8%), potato chips, corn chips, popcorn (5%), household shortening (4%), salad dressing (3%), breakfast cereal and candy (1%), the FDA reported in 2005.