The Food and Drug Administration has just removed “Generally Recognized As Safe” (GRAS) status from trans fats. Food manufacturers will be banned from using trans fat-containing oils, shortenings, and margarines. The ban is not based on credible science and will produce no public health benefits.
- What are trans fats? Trans fats are vegetable oils that are processed to be firm at room temperature. They’re found in vegetable shortening and foods cooked or made with shortening such as pastries, crackers and fried foods. They have been used in food preparation for 100 years — Procter & Gamble began selling the shortening Crisco in 1911. rans fat-based vegetable oils and margarine became the recommended substitute for butter and lard amid the 1970s-era alarm over a purported (and now debunked) link between saturated (animal) fats and heart disease.
- How did trans fats become controversial? During the 1990s, two Harvard researchers, Walter Willett and Alberto Ascherio, began publishing a series of epidemiologic studies claiming to link consumption of trans fats with increased risk of heart disease. In 2002, the National Institute of Medicine issued a report warning that there was no safe level of trans fat consumption.
- Enacted alarm. In 2006, New York City became the first jurisdiction to ban trans fats from restaurant-prepared foods. A few other local jurisdictions have since followed suit. However, the U.S. Food and Drug Administration (FDA) has not taken action against trans fats, although product labeling is required.
Science and health background.
- Do trans fats increase the risk of heart disease? There is no credible scientific evidence whatsoever showing that trans fats cause or increase the risk of heart disease.
- What is the purported mechanism by which trans fats are supposed to increase the risk of heart disease? Laboratory studies indicate that blood levels of LDL cholesterol (often referred to as “bad cholesterol”) increase temporarily after trans fats are consumed.
- Is this temporary rise in LDL cholesterol bad? Although chronic elevated LDL may increase the risk of heart disease, the increase in LDL from trans fat consumption is transient (temporary) and does not lead to permanently elevated LDL or heart disease. Importantly, heart disease is a complex, little-understood and multi-factorial phenomenon. The relationship between heart disease and LDL is not entirely understood as an elevated LDL level does not reliably predict heart disease.
- What do studies of humans show? The vast majority of the studies of trans fats involving human populations (i.e., epidemiology) have been conducted by Willett and/or Ascherio. Despite their results purporting to link trans fat consumption with increased risk of heart disease, these studies are not credible because:
- Statistical noise. Their results all fall within the realm of statistical noise, as determined by the traditional standards of science and statistics.
- Garbage in, garbage out. None of the consumption and/or medical data in any of the studies is sufficiently reliable. No one knows how much trans fat any study subject consumed or over what period of time. No one knows the cause or nature of any of the heart disease among the studies’ subjects. Without these key data, it is impossible to attribute heart disease to trans fat consumption with any degree of confidence.
Are there other reasons to doubt the purported link between trans fats and heart disease?
- The potential relationship of diet to heart disease risk is not well understood. Many common notions about diet and heart disease arising from the 1970s have proven to be false or at least more complicated than previously thought. Dietary saturated fat and salt, for example, are the not “killers” that they were touted as. Eggs and butter, in particular, were wrongly demonized. Dietary fiber is not a magic bullet for preventing heart disease. Consider the trans fat-relevant example of elevated cholesterol, long thought to cause heart disease and death. In the much-vaunted Framingham Heart Study — where 5,200 men and women in Framingham, Mass., have been extensively studied in over 1,000 published reports since 1948 — high cholesterol is not associated with increased heart disease risk after age 47. After age 47, in fact, those whose cholesterol went down had the highest risk of a heart attack.
- Willett and Ascherio have single-handedly tried to railroad trans fats. Not only did Willett and Ascherio conduct most of the epidemiology studies on trans fats, they also published many of the reviews of the epidemiology —i.e., essentially applauding their own work. This runs against the traditional notions of the scientific method where study results are supposed to be replicated and reviewed by other, independent scientists.
- Existing trans fats bans have accomplished nothing. There is no evidence that existing bans on trans fats have made anyone anywhere any healthier or reduced their risk of heart disease.
What is the harm is caused by a trans fat ban?
- Misleading the public. Wrongly blaming trans fats for heart disease misinforms, confuses and angers the public. When butter was declared to be unhealthy, trans fat-based margarine was supposed to be healthier. Now butter is “safer” than margarine. People were wrongly scared off eggs for decades.
- No substitute. While there are substitutes for trans fats in some products, for other products there are no substitutes, particularly in baking.