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A wave of newly published science and analysis from the 2008 International Symposium on Chylomicrons in Disease (ISCD) raises a warning flag to the global health community over an overlooked type of cholesterol. It also serves as a call to action towards further progress that will be featured at the next ISCD conference planned for March 2010.

The science focuses on chylomicrons – a type of cholesterol carrier formed in the intestine. Because chylomicrons are processed quickly, they are virtually undetected by common doctor-directed cholesterol tests. Now growing evidence points to chylomicrons as a major missing puzzle piece in the diagnosis and treatment of metabolic disorders that give rise to heart disease and stroke, diabetes, chronic obesity and other dangerous health conditions.

"The knowledge showcased at ISCD 2008 has tremendous implications for how we understand, diagnose and seek to reduce cardiovascular risk factors that are associated with chronic disease," says Dr. Spencer Proctor, ISCD Chair and Director of the Metabolic and Cardiovascular Diseases Laboratory at the Alberta Institute for Human Nutrition, University of Alberta. "It has become clear that chylomicrons, and the intestine in general, play a much larger and more active role in metabolism and health than has been previously recognized."

The complete ISCD findings are published in the September 2008 edition of Atherosclerosis Supplement. Excerpts from ISCD sessions along with an overview of award-winning presentations by student young investigators are also featured in a layman-oriented summary article, "Windows to the world of chylomicrons," available at www.ISCD2008.com.

One key finding links high levels of this cholesterol to intake of fructose corn syrup, found commonly in soda pop and other sweetened food stuffs, "This serves as further warning that particularly children and people with obesity should avoid these beverages and foods," says Proctor.

Another major finding indicates that the intestine may in some cases actually increase intestinal cholesterol production in a compensatory response to common cholesterol drugs, such as the well-known statins, that target a reduction in liver cholesterol production. Also, Canadian research lead by the University of Alberta indicates a healthy fatty acid – vaccenic acid – found in dairy and beef products may help reduce intestinal cholesterol production.

ISCD 2008, held earlier this year in Lake Louise, Alberta, Canada, was hosted by the Alberta Institute for Human Nutrition and the University of Alberta. It brought together a broad, multi-disciplinary range of scientists with expertise in chylomicrons, from more than 15 countries and several continents, covering the spectrum from basic discovery to clinical research. The agenda featured over 30 presentations and broad discussion of latest research, new opportunities and future challenges in this field. It also included presentations and awards focused on young investigators, helping to emphasize professional training and education at the international level.

With sponsorship including the pharmaceutical and agricultural sectors, ISCD served as an important event for these two sectors to come together in the collective interest of highlighting the importance of nutrition in chronic disease.

Chylomicrons are technically large lipoprotein particles – balls of biochemistry made up primarily of dietary fat and cholesterol – that form in the small intestine following a meal. These chylomicrons are absorbed into the bloodstream and transported throughout the body, where they deliver a portion of their contents to various tissues. They are also modified based on interaction with other lipoproteins in the blood.

The modified or "mature" chylomicrons are called "remnants," which, as new evidence further confirms, can build up on arterial walls. Remnants that pass through freely are ultimately transported to the liver and further broken down.

The entire cycle takes place in as little as 15 minutes or up to several hours following a meal. As a result, only about three percent of the cholesterol associated with chylomicrons is captured by blood sample cholesterol tests that are conducted following a 12 hour fasting period.

The growing body of evidence suggests this undetected intestinal cholesterol and the chylomicron remnants may be just as dangerous, or even more dangerous, than low density lipoproteins (LDL) cholesterol, which is the so-called 'bad' cholesterol produced by the liver, says Proctor. "This may explain why as many as half of the people diagnosed with cardiovascular disease do not have high LDL levels. Chylomicrons appear to be the hidden factor."

Information on the planned March 2010 ISCD event will be provided to ISCD participants and featured on the ISCD Web site as details are finalized.

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International scientists raise warning flag on intestinal cholesterol