These comments were delivered July l8, 2007 as part of a National Academy of Sciences debate between Dr. Whelan and the Center for Science in the Public Interest's Dr. Michael Jacobson:
The risks of trans fats as a cause of heart disease has been wildly exaggerated; calls for government agencies to ban trans fat in food are without scientific merit. Such bans would prevent few, if any, deaths from heart disease. Indeed it might be argued that such a move will cause harm by distracting attention from the real causes of heart disease.
High levels of dietary trans-fats (TFAs), derived primarily from partially hydrogenated vegetable oils, can raise levels of LDL, the so-called “bad cholesterol.” But TFAs are only one of several dietary factors that affect blood lipids and, more importantly, serum cholesterol is only one of several factors that may influence the risk of heart disease. Cigarette smoking and high blood pressure, as well as diabetes and obesity, contribute far more to heart disease than any specific dietary factor.
Any practicing physician who has treated patients with elevated cholesterol levels will tell you that even the strictest low-fat diets often result in only modest cholesterol reduction. So how could we expect significant effects on LDL cholesterol from banishing levels of just one type of fat — one that represents only about 2% of our total daily calorie intake? Those individuals with unhealthy lipid levels, of course, should choose polyunsaturated or monounsaturated fats. It's saturated fats, not trans-fats, that they should be concerned about — because it's saturated fats that represent over 10%, maybe 15% of caloric intake. Individuals struggling with excess blood lipid levels need to discuss with their physicians the option of cholesterol-lowering drugs.
You will hear that not only do trans fats increase the levels of LDL cholesterol, but they also decrease the levels of HDL or "good" cholesterol. This is true — but the experiments that demonstrated this effect were performed with levels of TFA that were clearly higher than those typically encountered in the American diet. The implications of this effect at a time when dietary TFAs are obviously decreasing are likely to be minimal, if the effect is at all detectable.
You will also be told that TFAs increase levels of biomarkers of inflammation — and atherosclerosis is now considered to result at least in part from inflammatory processes. But the data supporting this effect is still preliminary — it's epidemiological, or based on short-term studies.
In contrast, one human study demonstrated that compared to the effects of a diet high in saturated fat, people who switched to an equivalent amount of a TFA-containing diet actually experienced an improvement of arterial function. Again, this is just preliminary, but it suggests that we have far to go before we have a really complete picture of the role of TFA in the genesis or promotion of heart disease, compared to that of saturated fats or other dietary lipids. Why do we want to jump the gun on the research?
Given the scientific facts, then, why is there such an uproar about TFAs? I would like to put the proposed bans and government regulatory action in some perspective.
First, in recent years, public health authorities have increasingly turned to regulation to combat chronic disease in a fashion similar to using regulation to fight infectious disease — requiring water chlorination, inoculations, and so forth. An example is the New York City Health Department's decision in January 2006 to make diabetes a reportable disease — in the same way that sexually transmitted diseases are reportable. The problem is that government intervention for chronic diseases, which are primarily linked to lifestyle factors, is intrusive and simply will not work. By calling for a ban on TFAs in restaurant foods, the public-health establishment is responding as if TFAs were an imminent health threat — like listeria in deli meats. They are not.
Second, as the hyperbole about TFAs has escalated — with a _New York Times_ columnist opining that TFAs in Girl Scout cookies have killed more Americans than al Qaeda — physicians and scientists have largely remained mute on the topic. Silence is interpreted as agreement — and the momentum for the ban builds.
Third, the food industry has turned the fear of TFAs into a brilliant marketing strategy — trumpeting the "No Trans Fats" claim on labels. Unsuspecting customers will conclude from the absence of TFAs that products are healthier — and maybe even think they are reduced in calories — when in fact there are no health benefits. All fats, saturated or not, contain nine calories per gram. There are no caloric savings from replacing TFAs with other fats — although I speculate that the vast majority of Americans think trans-fat-free products are indeed reduced in calories.
Fourth, as to why the war against trans fats exists. Heart disease is the number one cause of death in America. There are those who believe it is better to do something rather than nothing — even if there is no evidence the proposed intervention will be efficacious.
Which reminds me of the old adage "For every complex problem there is a simple solution — and it never works."
What will replace the allegedly malicious TFAs? In the 1980s, the Center for Science in the Public Interest and associated activists fomented a frenzy about the beef tallow that fast-food restaurants used to fry potatoes because it contains cholesterol-raising saturated fats — and demanded that they stop it. And what did CSPI recommend to take its place? Partially hydrogenated vegetable oils with TFAs. Now the wheel has turned and CSPI is outraged over TFAs. And what fats will now replace TFAs in our diets? Beef tallow?
In a recent conference, the American Heart Association addressed this issue. The AHA Trans Fat Conference Planning Group noted that about 9 billion pounds of partially hydrogenated oils (the type that contain TFAs) will need to be replaced with other oils and fats. On the basis of company information, they estimated that only 3.25 billion pounds of key alternatives would be available in 2007. Such alternatives might include low-linoleic corn and cottonseed oils, which are not widely available, tropical oils that are high in saturated fats, new "trait-enhanced" oils, blends of liquid oils with harder components, modified hydrogenation-processed oils, and interesterified oils (not all of which have been fully evaluated for health effects yet).
We need to keep in mind that when making radical changes we must remember the law of unintended consequences. Furthermore, AHA notes that changes in the types of oil seed crops planted typically take about four years to reach the market. Although this timing can be accelerated, it is clear that acceptable alternatives are not now readily available in the required amounts. And the current interest in using some crops (e.g., corn) for fuel production will also decrease availability for food use. Thus, pushing for a federal ban on TFAs in the American diet may lead to use of less desirable fats — especially for some applications such as baked goods for which liquid oils are not acceptable.
We have lost perspective on the important threats to health: smoking, obesity, excessive alcohol use, and more. And if we ban trans fats, we move one step closer to endorsing the principle that government should determine what we eat and how we should live even when the data and expected benefits are skimpy.
A few more points to clarify my position — and the position of the American Council on Science and Health:
As part of an overall effort to reduce risk factors for heart disease, advice to the public to limit consumption of both saturated fatty acids and TFAs by substituting polyunsaturated or monounsaturated fats whenever possible is justified by the scientific evidence. Scare tactics, including claims that there should be zero tolerance for TFAs in the food supply, are not justified.
Overstating the negative health effects of TFAs, and the potential benefit of decreasing them is harmful to public health because:
–It overemphasizes this single dietary factor as opposed to other aspects of diet, other modifiable risk factors for coronary heart disease, and other public health priorities. A variety of factors — including modifiable ones such as cigarette smoking, high blood pressure, obesity, diabetes, physical inactivity, and blood cholesterol levels, as well as factors that cannot be modified, such as age and family history — all play roles in the causation of heart disease.
–Food choices influence several of the modifiable risk factors. An exaggerated focus on the role of TFAs, not backed up by solid data, could prompt people to pay less attention to other aspects of diet and other measures important in reducing their risk of heart disease, such as smoking cessation or weight loss.
–Even with regard to lipid levels alone, TFAs are not the only or the most important determinant. Data from U.S. national surveys show that LDL cholesterol levels in men aged 50 to 74 and women aged 60 to 74 years decreased between the mid-1970s and 2002, a period when TFA intake is believed to have changed very little. Clearly, other factors — such as changes in other aspects of diet or the increased use of lipid-lowering drugs — must have been responsible for this change.
A pioneer in the field of cholesterol and heart disease, Dr. David Kritchevsky of the Wistar Institute, noted just before his recent death: The kerfuffle over trans fats is just "the scare du jour " — with smoking, high blood pressure, obesity, and diets high in saturated fats being far more important heart threats. With trans fats now accounting for 1% to 2% of our caloric intake and saturated fats accounting for about 15%, the chances that a ban on trans fats in restaurants will reduce the risks of heart disease are about zero. Instead, the ban will only cause havoc in the restaurant industry and escalate costs of doing business, all of which will be passed on to consumers.
Perhaps the absurdity of the trans fat scare and its resulting restaurant ban was apparent in a quote from Four Seasons purchasing manager, Joel Patraker, who bragged that his dining landmark did not use trans fats, noting, "we use a large amount of wonderful, farm-fresh butter." Talk about out of the trans fat frying pan and into the saturated fat fire.
See also: ACSH's report on Trans Fatty Acids and Heart Disease.
Whelan and Jacobson at their
July 18, 2007 debate
before the National Academy of