Food manufacturers have been making a concerted effort to remove trans fats from their products and reduce levels of saturated fats. Trans fats have been linked to health risks as diverse as cardiovascular disease and prostate cancer, and the growing level of scientific evidence supporting their adverse impact on health has led to well-publicised bans in New York City restaurants, and to other cities, like Boston and Chicago, considering similar measures. McDonald's has been making concerted efforts to improve its healthy image. But given the popularity and recognition of the restaurants, the removal of trans fats, announced recently by chief executive Jim Skinner, should help reinforce the message to consumers to be selective in their fat choices. For food manufacturers taking parallel measures, this would also translate into greater market for their trans fat free products, as consumers are more likely to look out for trans fat free claims on labels and marketing materials. Though trace amounts of trans fats are found naturally, in dairy and meats, the vast majority are formed during the partial hydrogenation of vegetable oil (PHVO) that converts the oil into semi-solids for a variety of food applications. Hydrogenated fats have been widely used by food producers for a century, but fears about their trans fat content - and the risk to health that these can cause - have prompted companies to begin looking for alternative oils that provide the same function without the attendant dangers. Dairy ingredients group Land O'Lakes, vegetable oil giant Bunge, DuPont's Pioneer Hi-Bred unit, and Iowa firm Asoyia, are just a handful of a growing number of firms to recently roll out ingredients to food manufacturers eager to slice the trans fats out of their formulations. According to DuPont, for example, new oil testing results have confirmed that its new high oleic soybean oil trait contains at least 80 per cent oleic acid, significantly increasing the stability of the oil when used in frying and food processing. This, DuPont said, meant that the oil did not need to be hydrogenated and that it thus contained only "negligible" amounts of trans fats. The move by McDonald's to switch to cooking oils free of trans fats in all of its restaurants comes several years after a landmark settlement that saw the fast food giant agreeing to pay $8.5 million to settle a lawsuit and donating $7 million to the American Heart Association, as well as spending another $1.5 million to inform the public of its trans fat plans. The settlement was the result of action by a small US activist group called BanTransFat.com against McDonalds. The San-Francisco activists challenged that although McDonalds had announced it would voluntarily change to a cooking oil with less trans fat by February 2003, the firm had failed to make the switch, and had neglected to inform the public of this status quo. Proving to be a potent lobbyist, Stephen Joseph, the lawyer who founded BanTransFats.com, first gained publicity for his cause by suing Kraft Foods to highlight the trans fat content of its iconic food product, Oreo cookies. The company has since moved to remove trans fats from its snack foods. More recently, BanTransFats.com was involved in making Tiburon, California 'America's first trans fat-free city' and assisted New York City in developing its trans fat-free program. This led to New York City passing a regulation banning trans fat in December 2006.