Q&A: Trans fat

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

Governor Arnold Schwarzenegger signed a bill that prohibits restaurants from using trans fat in any form, 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 have been linked to coronary heart disease and other chronic diseases such as diabetes.   

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

What is 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 earlier days, the industry actually used saturated fat such as beef tallow. Later, saturated fat was found to raise low density lipoprotein (LDL) or bad cholesterol, increasing the 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 that 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 (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 do 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 that trans fat may also hurt learning ability and memory. 

Harvard epidemiologists and nutritionists estimated that trans fat is involved in up to 100,000 deaths from heart disease 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 the Harvard School of Public Health recommend that consumers completely avoid intake of trans fat or avoid as much as they can. 

What does the government say about the safety ftrans fat?

The Food and Drug Administration sometimes if not always makes statements such as '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 suggests otherwise. 

How much trans fat do Americans consume each year? 

Consumers in the US eat trans-fats 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 to 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 that trans fats do nothing good except for providing energy, and they recommend that consumers should completely avoid trans fat. 

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

No. No government, federal or state, has ever banned the use of trans fat in packaged food or food prepared at restaurants. New York City just proposed on Sept 26, 2006, to phase out the use of trans fat in restaurants. In six months, restaurants should use margarine and shortening without trans fat for frying and spreads. But 0.5 grams per serving of trans fat are still 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 that the trans fat content in restaurant-prepared foods needs to be absolutely zero. 

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

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

How could consumers know if 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 'zero trans fat,' 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 as 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 that are refined may contain trans fat. A food with polyunsaturated fat may produce some trans fat after it is subjected 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 are not labeled if only a little bit is introduced during the processing.  

What are the major food sources of 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.

By Ben Wasserman, and edited by Heather Kelley.
Jul 27, 2008 - 10:37:07 AM