To many the proposed FDA rule to deny GRAS status to partially hydrogenated oil—and thereby in effect banning it from use—would be a great public health benefit. However, this proposed rule is not without consequences to many individuals, so it is critical that this decision is made carefully.
The FDA and others have stated that further decreases in trans fatty acid consumption could decrease thousands of cardiac events and deaths. These calculations of saving lives by further lowering trans fatty acid consumption assume that the biological effects of trans fatty acid follow a dose dependent linear response. Unfortunately, the pharmokinetics of the biological effects of trans fatty acids are difficult if not impossible to confirm since most studies that show adverse effects of trans fatty acids had to use dietary trans levels in excess of 5% of total energy. FDA has calculated that trans fatty acid consumption of partially hydrogenated oils has decreased from 4.6 g per day in 2003 to 1.3 g per day (2.1 to 0.6% of total energy) in 2010. It is very common for kinetics to not be linear especially at extremely low or high concentrations of bioactive agents. Therefore, it does not seem scientifically prudent to make a bold statement of how many deaths a food ingredient is causing without any clinical data.
One could argue trans fatty acids should be eliminated regardless of what we know about their biological effects because they have no known nutritional benefits. However, when making policy recommendations for the removal of a food ingredient, one always needs to examine what will be used in its place so we do not repeat past problems like recommending fat removal only to increase sugar consumption. Certain foods require solid fats for function (e.g., baked goods) so partially hydrogenated oil will have to be replaced with another solid fat such as palm oil. Some may argue that this is OK because trans fatty acids are much worse than saturated fatty acids. However, oils are partially hydrogenated so that small amounts of the unsaturated fatty acids are removed and thus they can contain significant amounts of polyunsaturated fatty acids (>30%) compared to palm oil (<10%). Oils such as palm also contain higher levels of saturated fatty acids (>45%) than partially hydrogenated oil (<20%). Unfortunately, the health consequences of replacing partially hydrogenated oil with tropical oils in diets that already have low levels of trans fatty acids is unknown.
There are potential solid fats such as interesterified fats and organogels that could provide the functionality needed in foods currently containing partially hydrogenated oils without drastically increasing saturated fatty acid levels. However, these fats are more expensive and would increase food costs. At a time when large numbers of Americans require food assistance and with a political environment that will likely decrease food aid, the proposed rule would largely affect Americans who are the least food secure.
The proposed rule is also a problem for future technology development. Some partial hydrogenation technologies, such as electrochemical hydrogenation, can produce low levels of trans fatty acids. Could these products be used in foods if the proposed rule is passed? If so, what criteria would be used to determine if they are GRAS?
It is critical that food regulations and policy are based on sound scientific evidence since removal on any food ingredient could have unintended consequences. Obtaining the data to make sound regulatory decisions is very difficult under the current research funding environment and this issue again highlights the need for increased funding for food and nutrition research or the development of public-private funding mechanisms that could sponsor the clinical trials needed to evaluate the safety and health-promoting properties of foods.