Not too long ago, the dangers of trans fatty acids were known only to researchers and some advanced healthcare practitioners. Now the term has entered the public vocabulary, and public health policy is changing as a result. The Canadian government is under pressure from the Heart and Stroke Foundation to remove this toxin from the food supply altogether. Stateside, New York’s mayor recently signed into law a bill that would restrict the use of artificial trans fats in New York’s restaurants. It is just the beginning.
In case you haven’t heard, trans fats—found in fried foods (such as French fries), baked foods (like donuts), snack foods (like some crackers), margarines, vegetable shortening, and some salad dressings—throw cholesterol out of balance, cause inflammation, and increase the risk of coronary heart disease, among many other ailments. Trans fats have been prized by the food industry for their ability to prolong baked goods’ shelf life and to last longer in deep fryers. But the evidence against them is piling up.
[blockquote author=”Frank B. Hu, MD, Ph.D.” pull=”pullleft”]“Several previous studies have found a link between trans fat intake and the risk of coronary heart disease,” said Frank B. Hu, MD, Ph.D., of the Department of Nutrition at the Harvard School of Public Health. [/blockquote]
Dr. Hu and colleagues published a study that showed trans fats raised the risk of coronary heart disease in women. “It’s hard to estimate just how much of an effect trans fats are exerting if you are only using dietary assessments to gauge exposure. So we measured some trans fat in red blood cells, which is directly correlated to consumption.”
As part of the Nurses’ Health Study from 1989 to 1990, blood samples were collected from 32,826 women. During six years of follow-up, 166 cases of coronary heart disease occurred in study participants. These were compared to 327 women without the disease. Total trans fatty acid content in red blood cells closely matched some trans fats in the diet. Higher total trans fatty acid content was associated with higher LDL (“bad”) cholesterol, lower HDL (“good”) cholesterol, and an elevated risk of coronary heart disease. Among women with the highest amounts of trans fats, the risk of coronary heart disease tripled.
In the average American diet, 2 to 3% of the total calories come from industrially produced trans fatty acids. The US Department of Agriculture would like to see that figure drop to 1% or less.
“Trans fat intake has been substantially reduced in European countries,” Dr. Hu noted, “whereas consumption in the United States is relatively stable. Elimination of partially hydrogenated oils and other sources of trans fat from the diet is likely to make a significant contribution to the goal of reducing the burden of cardiovascular diseases.”