Multidisciplinary investigation of trans fat

Trans fat, derived from the partial hydrogenation of vegetable oils, is present in many processed foods and bakery items. But in the US the FDA is currently reviewing evidence that trans fats are not generally recognised as safe (GRAS) for any use in food.

Although the evidence linking trans fat with heart disease has mounted for years, the evolving science has at times been equivocal, largely because of two unique sources of trans fat: dietary and ruminant.

“While there is an almost unanimous view that trans fatty acid should be phased out to less than 1% of total daily energy consumption, a similar consensus has not been reached with respect to TFA from ruminant meats and dairy since the amounts likely to be consumed are modest and outweighed by nutritional benefit,” said Paul Nestel, MD, professor of medicine and senior faculty at Baker IDI Heart and Diabetes Institute in Victoria, Australia, when asked about that evidence.

Scientific evidence linking various health risks with the consumption of trans fat resulted in the FDA announcing a preliminary ruling that trans fats are not generally recognised as safe (GRAS) for any use in food. This preliminary ruling, which proclaims partially hydrogenated oils as food additives, triggered a public comment period that ended on 8 March 2014.

The FDA will now review the evidence that dietary trans fat adversely impacts human health, and then decide whether to restrict partially hydrogenated oils (PHOs) from the American diet, and by how much.

According to Joshua T Cohen, deputy director of the Center for the Evaluation of Value and Risk in Health and a research associate professor of medicine at the Institute for Clinical Research and Health Policy Studies at Tufts Medical Center, Boston, the benefit of restricting trans fat at the individual level is clearly positive. He further suggested recently that “a comparison of FDA’s proposed regulation with other risks and with other measures to improve health reveals that it confers substantial individual benefits at a relatively low cost”.

Clinical Therapeutics features a special report in its March issue focusing on the science and policy leading up to the US FDA’s preliminary steps towards restricting industrially produced trans fatty acids at the federal level.

The report includes papers by Dr Nestel, Dr Cohen, R Rammy Assaf and Rishi Sood, MPH. Dr Nestel describes the cumulative evidence linking TFA and cardiovascular disease while Dr Cohen measures regulatory action by the FDA from a policy perspective. Mr Assaf, a recent intern at the World Health Organization Health Systems and Services in Geneva, Switzerland, and a student at the University of Miami Miller School of Medicine, provides context for FDA action by describing the history of TFA regulations. Finally, Mr Sood, health policy analyst, Bureau of Primary Care Access and Planning, New York City Department of Health and Mental Hygiene, describes the outcome of a voluntary TFA ban in Nassau County, NY. Dr Ryan, Associate Professor and director, Division of Primary Care/Health Services Research and Development in the Department of Family Medicine and Community Health at the University of Miami Miller School of Medicine, and Clinical Therapeutic Topic Editor for Endocrinology, Diabetes and Other Endocrine Disorders, summarises the trans fatty acid debate in his editorial, ‘No Longer Generally Recognized As Safe (‘GRAS’)’.

Clinical Therapeutics Updates can be freely accessed at the journal’s website