South Africans’ health is set to improve when new legislation kicks in on 17 August 2011 to limit artery-clogging artificial trans fats in all food products. The Department of Health has confirmed that the use of artificial trans fats, which has been linked to an increased risk of heart disease, will be limited to a maximum of 2% in all foods.
Not everyone is enthusiastic about the new legislation.
"This legislation is, unfortunately, not based on any factual evidence that South African diets in general contain excessive amounts of trans fatty acids, and seems to be more a reaction to emotion and political view - both local and international,” says Andrew MacKenzie, an independent expert on oils and fats who has worked in the food manufacturing industry for many years.
“I honestly don’t think it’s justified or likely to be of any benefit; in fact it may well have the opposite effect. Simply taking out the trans fats is not the end of the story.”
According to MacKenzie trans fats in margarines and similar spreads (a major source of fats in the average diet) play an important role in that they contribute “body” at ambient temperature (so-called “stable on the table”), yet melt at mouth temperature (thus avoiding the “cold sausage roll” fatty sensation from high melting components).
Subsequently, the trans fats have to be replaced by (mainly) saturated fats which are also regarded as "bad". (Saturated fats are a well-known precursor to high cholesterol and heart disease.)
“To meet the conflicting requirements of room temperature stability and good oral melting properties necessitates the use of specialised mixtures of (mostly) ‘tropical’ fats and oils which contain shorter chain saturated fatty acids that are generally regarded as 'undesirable’,” MacKenzie explains. “Thus, in general, we'll see an increase in saturated (mainly short chain) fat content to counter the textural and organoleptic [sensory] problems caused by the removal of trans fats.”
Initial good intentions
Ironically, trans fats were initially developed with good intentions. When it was discovered in the late 1970s that saturated animal fats could lead to high cholesterol and heart disease, the food industry looked at healthier, unsaturated vegetable oils to replace butter, but found that many of them became rancid quickly due to oxidation. As a result they started using hydrogenation by which hydrogen is bubbled through vegetable oils to increase their shelf life, keep foods fresh for longer and improve their taste and texture.