There has been a great deal of ballyhoo this week over the decision by the U.S. Food and Drug Administration to require food products to include notices as to how much trans fatty acids they carry. A spokesman of the Center for Science in the Public Interest argued on CNN’s “Crossfire” that the issue wasn’t about obesity, but about heart disease. Paul Begala intimated on the same program that the FDA’s decision would save lives. Based on the research to date, neither statement is necessarily correct.
Trans-fatty acids are a particular form of saturated fat that seems to have a greater effect on the human body than general saturated fats. In particular, it appears to raise LDL cholesterol ("bad" cholesterol) and lower HDL cholesterol ("good" cholesterol). Higher levels of bad cholesterol have been shown to be linked to a greater risk of heart disease and other serious illnesses. It is for this reason that a panel from the Institute of Medicine stated that the safest upper limit for consumption of trans-fats was zero. However, the issue is not quite as clear-cut as people who are concerned about labeling would like. Studies have repeatedly failed to show a serious link between ingestion of trans-fatty acids and heart disease and early death. One 1997 study, for instance, which looked at the causes of coronary ‘events’ and deaths found no real correlation between intake of the acids and having a heart attack. Someone who ate six grams of trans-fatty acid a day was only 14 percent more likely to have a heart attack than someone who ate one gram, although they were 39 percent more likely to die. Yet even that 39 percent relative risk is not high enough to attribute definitely causation to the trans-fatty acids. The same study found that people who ate 2.7 grams of the substance per day were actually 10 percent less likely to die of heart disease.
Other studies have shown similarly small relative risks of heart disease. Careful epidemiologists do not draw conclusions from relative risks this small, because there may be other factors at play. It would be easy, for instance, to say that drinking causes lung cancer based on a comparison between amount of alcohol ingested and the prevalence of the disease. But that would not take account of the fact that many drinkers smoke.
So when people say that labeling food is about protecting you from heart disease, they may be right, but they may not be. As the Institute of Medicine pointed out in its report on the subject, it could not recommend that people cut trans-fatty acids out of their diet because many foods that contain them naturally also contain other nutrients that are essential to the body’s well-being. Breast milk, for instance, contains trans-fats. If someone decides to cut out foods simply because of the presence of trans-fats on the label, they may be damaging their health, not improving it.
* In an effort to improve the environment, authorities worldwide have been keeping records of how much mercury has been released into the atmosphere for many years. These records suggest that there were substantial reductions in such emissions during the 1980s, after which emissions leveled off to a relatively constant figure. We would therefore expect to see these trends reflected in actual measurements taken from the atmosphere.
But that has not been the case. Recent research by a group of German, South African, Canadian and Scandinavian researchers headed by Franz Slemr of the German Max-Planck-Institut für Chemie has found some interesting discrepancies with the empirical data. They found that atmospheric concentrations of mercury increased from the 1970s to a peak in the 1980s, followed by a rapid decline to a minimum in 1996, after which they have remained constant.
As the researchers point out, this is not consistent with the record of the release of anthropogenic (caused by mankind) mercury and suggests that there may be a bigger role for natural emission of mercury than is currently thought. Once again, scientists’ assumptions that man is mostly responsible for changes in the atmosphere seem less convincing the more we know about what is actually happening. We still have a lot to learn about the way the atmosphere operates.
* On July 3, the Energy Information Administration (EIA) released an examination of the economic effects of the Climate Stewardship Act 2003, a bill supported by Sens. John McCain (R.-Ariz.) and Joe Lieberman (D.-Conn.), which seeks to restrain carbon dioxide emissions by instituting a series of tradable allowances for carbon dioxide production. The EIA estimated that the new restrictions would cost the American economy $507 billion between 2010 and 2025.
The Pew Center on Global Climate Change released its own analysis of the EIA study and commented, "The Pew Center has examined the EIA analysis and believes that the model’s structure, combined with unrealistic input assumptions and the limited sensitivity cases selected, results in unrealistically high cost projections."
Funnily enough, those who are concerned about global warming alarmism have repeatedly warned that the climate models on which the scare is based have structural problems, unrealistic input assumptions, not enough sensitivity and result in unrealistically high warming projections.