Higher Trans Fat Levels in Blood Associated With Elevated Risk of Heart Disease

March 28, 2007

Boston, MA — High consumption of trans fat, found mainly in partially hydrogenated vegetable oils and widely used by the food industry, has been linked to an increased risk of coronary heart disease (CHD). New York and Philadelphia have passed measures eliminating its use in restaurants, and other cities are considering similar bans. A new study from the Harvard School of Public Health (HSPH) provides the strongest association to date between trans fat and heart disease. It found that women in the U.S. with the highest levels of trans fat in their blood had three times the risk of CHD as those with the lowest levels. The study was published online on March 26, 2007, and will appear in the April 10, 2007 print issue of Circulation: Journal of the American Heart Association.

"The strength of this study is that the amount of trans fatty acid levels was measured in blood samples from the study population. Because humans cannot synthesize trans fatty acids, the amount of trans fat in red blood cells is an excellent biomarker of trans fat intake," said senior author Frank Hu, associate professor of nutrition and epidemiology at HSPH.

Clinical trials have shown that trans fatty acids increase LDL cholesterol and lower HDL cholesterol, making them the only class of fatty acids, which includes saturated fat, to have this dual effect. HDL (high-density lipoprotein) is considered a "good" cholesterol; LDL (low-density lipoprotein) a "bad" cholesterol.

The researchers, led by Hu and lead author Qi Sun, a graduate research assistant at HSPH, set out to test the assumption that higher trans fatty acid levels in erythrocytes—red blood cells—were associated with a higher risk of heart disease among U.S. women. Blood samples collected in 1989 and 1990 from 32,826 participants in the Brigham and Women's Hospital-based Nurses' Health Study were examined. During six years of follow-up, 166 cases of CHD were diagnosed and matched with 327 controls for age, smoking status, fasting status and date of blood drawing.

After adjusting for age, smoking status and other dietary and lifestyle cardiovascular risk factors, the researchers found that a higher level of trans fatty acids in red blood cells was associated with an elevated risk of CHD. The risk among women in the top quartile of trans fat levels was triple that of the lowest quartile. "Positive associations have been shown in earlier studies based on dietary data provided by the participants, but the use of biomarkers of trans fatty acids is believed to be more reliable than self-reports. This is probably the reason why we see an even stronger association between blood levels of trans fat and risk of CHD in this study," said Sun.

"These data provide further justifications for current efforts to remove trans fat from foods and restaurant meals," said Hu. "Trans fat intake in the U.S. is still high. Reducing trans fat intake should remain an important public health priority."

The study was supported by the National Institutes of Health.

"A Prospective Study of Trans Fatty Acids in Erythrocytes and Risk of Coronary Heart Disease," Qi Sun, Jing Ma, Hannia Campos, Susan E. Hankinson, JoAnn E. Manson, Meir J. Stampfer, Kathryn M. Rexrode, Walter C. Willett, Frank B. Hu, Circulation, April 10, 2007.

Harvard School of Public Health

---

---

	Trans Fatty Acids by Albert J. Dijkstra (Editor), Richard J. Hamilton (Editor), Wolf Hamm (Editor) Trans fatty acids (TFAs) have been used for many years to impart desirable physical characteristics to fats and fat blends used in food manufacturing. However, clinical trials and epidemiological studies conducted over the last thirty years have shown that TFAs can increase “bad” cholesterol levels in the blood while reducing “good” cholesterol. Accordingly, they are also linked with increased risks of coronary heart disease, thrombosis and strokes. For this reason, the food industry has been obliged to find alternatives to TFAs, thus enabling it to meet the presumed consumer demand for “low” or “no” trans fats products. The issue is becoming more and more pressing. For example, US labelling regulations now require that food manufacturers state the trans fat content of...
	Trans Fatty Acids and Coronary Heart Disease Risk (ILSI Europe Concise Monograph) by Penny M. Kris-Etherton (Author), Kris Etherton (Author), Robert J. Nicolosi (Author)
	Trans Fats: the Hidden Killer in our Food by Judith Shaw (Author) EVERYTHING YOU NEED TO KNOW BEFORE THE FDA'S NEW LABEL LAWS GO INTO EFFECT IN 2006 Identify foods made with trans fatty acids -- the dangerous manufactured ingredient in partially hydrogenated vegetable oils Rid your diet of trans fats -- at home, in restaurants, in take out, and in packaged foods Be healthier -- and live longer
	IOM recommends change in nutrition labeling: push to include trans fatty acids.(Clinical Rounds)(Institute of Medicine): An article from: Internal Medicine News by Norra MacReady (Author) This digital document is an article from Internal Medicine News, published by International Medical News Group on February 1, 2004. The length of the article is 922 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser. Citation Details Title: IOM recommends change in nutrition labeling: push to include trans fatty acids.(Clinical Rounds)(Institute of Medicine) Author: Norra MacReady Publication: Internal Medicine News (Magazine/Journal) Date: February 1, 2004 Publisher: International Medical News Group Volume: 37 Issue: 3 Page: 17(1) Distributed by Thomson...
	FDA to require labeling of trans fatty acids.(US Food and Drug Administration): An article from: Food & Drink Weekly by Informa Economics, Inc. (Publisher) This digital document is an article from Food & Drink Weekly, published by Informa Economics, Inc. on July 14, 2003. The length of the article is 462 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser. Citation Details Title: FDA to require labeling of trans fatty acids.(US Food and Drug Administration) Publication: Food & Drink Weekly (Newsletter) Date: July 14, 2003 Publisher: Informa Economics, Inc. Volume: 9 Issue: 27 Page: 1(2) Distributed by Thomson...
	Federal Dietary Guidelines to Target 'Bad' Fats.(trans fatty acids; saturated fats)(Brief Article): An article from: Family Practice News by Winnie Anne Imperio (Author) This digital document is an article from Family Practice News, published by International Medical News Group on April 15, 2000. The length of the article is 578 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser. Citation Details Title: Federal Dietary Guidelines to Target 'Bad' Fats.(trans fatty acids; saturated fats)(Brief Article) Author: Winnie Anne Imperio Publication: Family Practice News (Magazine/Journal) Date: April 15, 2000 Publisher: International Medical News Group Volume: 30 Issue: 8 Page: 8 Article Type: Brief Article Distributed by Thomson...
	Food Labels Listing 'Trans Fatty Acids' Could Save Lives, Says FDA.: An article from: Food & Drink Weekly by Informa Economics, Inc. (Publisher) This digital document is an article from Food & Drink Weekly, published by Informa Economics, Inc. on June 26, 2000. The length of the article is 782 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser. Citation Details Title: Food Labels Listing 'Trans Fatty Acids' Could Save Lives, Says FDA. Publication: Food & Drink Weekly (Newsletter) Date: June 26, 2000 Publisher: Informa Economics, Inc. Volume: 6 Issue: 24 Page: 1 Distributed by Thomson...
	Trans-Fatty Acids Linked to High Blood Pressure.: An article from: Family Practice News by Greg Borzo (Author) This digital document is an article from Family Practice News, published by International Medical News Group on October 15, 2000. The length of the article is 422 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser. Citation Details Title: Trans-Fatty Acids Linked to High Blood Pressure. Author: Greg Borzo Publication: Family Practice News (Magazine/Journal) Date: October 15, 2000 Publisher: International Medical News Group Volume: 30 Issue: 20 Page: 18 Distributed by Thomson...
	Vegetable oil spread with no trans fatty acids: olive, canola spreads resemble soft margarine.: An article from: Food Processing by Fran LaBell (Author) This digital document is an article from Food Processing, published by Putman Media, Inc. on June 1, 1993. The length of the article is 413 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser. From the supplier: Researchers at Arthur D. Little Inc in Cambridge, MA, working with L and G Pure Foods of Pacific Palisades, CA, have developed a vegetable oil spread that tastes like butter and has the appearance and texture of light margarine. However, it contains no trans fatty acid. The new spread uses either an olive oil or canola oil base and involves oil-in-water emulsion technology. It will be of particular...
	Watch those trans-fatty acids!(NUTRITION): An article from: A Friend Indeed by Nancy Heidenreich (Author) This digital document is an article from A Friend Indeed, published by Thomson Gale on January 1, 2006. The length of the article is 739 words. The page length shown above is based on a typical 300-word page. The article is delivered in HTML format and is available in your Amazon.com Digital Locker immediately after purchase. You can view it with any web browser. Citation Details Title: Watch those trans-fatty acids!(NUTRITION) Author: Nancy Heidenreich Publication: A Friend Indeed (Newsletter) Date: January 1, 2006 Publisher: Thomson Gale Volume: 23 Issue: 6 Page: 6(1) Distributed by Thomson Gale