July 28, 2009
Atherosclerotic cardiovascular disease remains the leading cause of death as people age. One of the chief contributing factors remains high levels of blood fats. As society has become aware of this, there has been a slight decrease in blood cholesterol levels in the U.S. since the late 1980s, however, consumption of saturated and trans fats remains above recommended levels. Only one-quarter of U.S. adults with high cholesterol levels have it under control. About 24 million U.S. adults are on cholesterol lowering medications. Therefore controlling dietary fat intake is extremely important, but changing society’s nutrition-related behaviors is a major challenge.
Trans fats are mostly artificial fats that do not provide any health benefits. In similar amounts they are far stronger in increasing the risk of heart disease than the naturally occurring saturated fats. They increase low-density lipoprotein (LDL) cholesterol levels (the bad cholesterol), decrease high-density lipoprotein (HDL) cholesterol levels (the good cholesterol), increase systemic inflammation and affect insulin sensitivity (contributing to high blood sugar levels). It is reported that a 2% increase in energy intake from trans fats may increase the risk of a heart event by up to 23%. On an annual basis 6% to 19% of heart disease events and 30,000 or more premature deaths are estimated to occur in the U.S. because of trans fat consumption.
In the early 1900s trans fats became popular with the hydrogenation of vegetable oils and the development of processed foods, especially baked/fried goods and spreads. These chemically modified oils were popular due to the extended product shelf life/stability, low cost and flavor. In the 1970s, margarine, made from partially hydrogenated oil was even promoted as a healthier alternative to butter. It was in the 1990s that the dangers of trans fats were identified. By 2006 the U.S. Food and Drug Administration (FDA) required that all packaged goods display information on trans fat content. Products with less than 0.5 grams of trans fats per serving (although not completely negligible) can be labeled with “zero grams trans fat.” Attentive shoppers can now avoid trans fats in packaged foods but this requires close reading of labels. Unfortunately avoiding trans fats at restaurants is more difficult because they generally do not disclose nutritional information. In society this is problematic since restaurants in this country now provide about one third of the daily caloric intake.
Artificial trans fats are an unnecessary ingredient that pose a substantial risk to heart health. Eliminating trans fats, however, and using alternatives on a global scale will be challenging to accomplish quickly. Corn oils are healthier but their supply is more limited. Soybean oils require some hydrogenation to be acceptable. Proprietary trait-enhanced oils are emerging, but development is slow and expensive. Certainly we need to be aggressive to reduce trans fat exposures at schools and in people most vulnerable to atherosclerotic disease.