The modern, industrialized diet has become heavily dependent on the use of trans fats, particularly for the last half of the century. Trans fats were developed in 1902. At this time in dietary history, butter, lard and beef tallow were the most consumed fats. Trans fat was developed to offer a cheap alternative to the public, by converting the then inexpensive whale oil into a stable, marketable product.
Over the last two decades the health ramifications of trans fats has been unveiled. In response many restaurants and food manufacturers have eliminated its use, however there are still many products on the market lurking with trans fats. Trans fat's affect on blood cholesterol levels has been widely known. Hopefully the new studies linking it to aggression will be the final push to eradicate it from the industry.
Trans fats are made when an unsaturated fat has hydrogen added to it. In liquid unsaturated fats, such as vegetable oils, the atoms are configured in double bonds with carbon linking to carbon. In solid saturated fats, there are no double bonds because it is "saturated" with hydrogen forming single bonds. The trans fat is partially hydrogenated and contains mostly single bonds with one or more double bonds, so it is technically not a saturated fat. This is why trans fats can be solid, yet malleable and easily melted.
Trans fats can occur in nature and have not been found to cause the same negative affects as trans fats produced synthetically. Research is still ongoing trying to determine why synthetically produced trans fats have such adverse consequences.
Trans fats quickly infiltrated the Western diet for several reasons. First and foremost, the fat is cheap and had a long shelf life. Trans fats become rancid at a much slower rate because free radicals attack double bonds, which trans fats have fewer of. This combined with the assumption of health benefits because trans fats are technically partially unsaturated, and butter had no chance.
An article by Huffington Post
recently mentions a study
which adds to trans fats' already long list of faults. The study sampled over one thousand men and women, who were healthy and free of diseases such are diabetes, heart disease, HIV, or cancer. The study found that individuals who consumed a greater quantity of trans fat in their diet, regardless of sex, age, or education, were more likely to show signs of aggression or irritability. Although this study doesn't definitively demonstrate causality, it should lead us to question the ongoing dependence of trans fat in prisons and school lunches.