Trans Fats May Raise Risk of Gallstones
Study of 46,000 men shows 'modest' increase in risk of gallstone disease
May 11, 2005 -- Eating a lot of trans fats (trans-fatty acids) could raise the risk of gallstone disease, researchers report in the Archives of Internal Medicine.
Their 14-year study of almost 46,000 men showed that those who consumed the most trans fats had a 23% higher risk of gallstone disease than those who ate the least amount of trans fats.
That's a "modest" increase, say the researchers, who included Chung-Jyi Tsai, MD, ScD, of the University of Kentucky Medical Center.
Gallstone disease is common in the U.S. and other Western countries, and it's increasingly a major cause of digestive illnesses that prompt hospitalization, say Tsai and colleagues. Gallstones occur in about 20% of women and 10% of men by the age of 60. The risk of having gallstones increases with age and obesity.
About Trans Fats
Trans fats (also called hydrogenated fats) are found in many processed foods, including some crackers, cookies, baked goods, chips, and snack foods. They're made by turning liquid vegetable oils into solid products like margarine and shortening.
These fats are not the same as saturated fats that are also known to increase LDL "bad" cholesterol.
"There has been concern for years that high intake of trans-fatty acids could have adverse health effects because they are structurally similar to saturated fats and lack the essential metabolic activity of the parent compounds," write the researchers.
In other words, trans fats may be too much like artery-clogging saturated fats and too little like the original fats (vegetable oils) they're made from.
Trans fats also naturally occur in small amounts in some animal products, such as butter, milk, cheese, beef, and lamb, says the web site of the FDA's Center for Food Safety and Applied Nutrition (CFSAN).
Studies have been "inconclusive" about the impact of trans fats on blood lipid levels, say Tsai and colleagues. Some research has shown that trans fats can reduce HDL "good" cholesterol and increase LDL "bad" cholesterol, they say.
The CFSAN puts it more bluntly: "Trans fat behaves like saturated fat by raising LDL cholesterol that increases your risk of coronary heart disease."
LDL cholesterol is notorious for clogging arteries, raising the risk of heart attack and stroke. Research has shown that in Western countries, about 80% of gallstones are cholesterol stones, says Tsai's study.