Omega-3 Fatty Acids Keep Arteries Healthy

New research from Columbia University Medical Center continues to shed light on the benefits of making fish a staple of any diet.

Fish are generally rich in omega-3 fatty acids, which have shown benefit in many health areas such as helping to prevent mental illness and delaying some of the disabilities associated with aging. Eating wild tuna, sardines, salmon and other cold water fish appears to protect people against clogged arteries. Omega-3 fatty acids can also lower triglycerides, a type of fat often found in the bloodstream.

Now, a CUMC research team led by Richard J. Deckelbaum, M.D., Director of the Columbia Institute of Human Nutrition, has found that a diet rich in fish oils can prevent the accumulation of fat in the aorta, the main artery leaving the heart. The beneficial actions of fish oil that block cholesterol buildup in arteries are even found at high fat intakes.

The study was conducted in three separate populations of mice: one that was fed a balanced diet, one that was fed a diet resembling a “Western” diet high in saturated fat, and a third that was fed a high fish fat diet rich in omega-3 fatty acids.

Researchers in Dr. Deckelbaum’s laboratory, including Chuchun Liz Chang, a Ph.D. student in nutritional and metabolic biology, found that the fatty acids contained in fish oil markedly inhibit the entry of “bad,” or LDL, cholesterol into arteries and, as a result, much less cholesterol collects in these vessels.

They found that this is related to the ability of those fatty acids to markedly decrease lipoprotein lipase, a molecule that traps LDL in the arterial wall. This will likely prove to be important as a new mechanism which helps explain benefits of omega-3 fatty acids on heart health.

Dr. Deckelbaum advises those interested in increasing omega-3 intakes do so by either increasing fish intake or by using supplements that contain the “long-chain” fatty acids, EPA and DHA, which are found in cold water fish.

The research was published February 5, 2009 by the American Heart Association’s Arteriolosclerosis, Thrombosis and Vascular Biology, and is supported in part by grants from the National Institutes of Health.

The mission of the Institute of Human Nutrition (IHN) is to provide outstanding academic, professional education, and training programs in human nutrition and conduct basic science and translational research on the role of nutrition in human health. The Institute’s educational outreach includes conferences, symposia, and other initiatives for health practitioners, educators, industry, and non-profit organizations to advance knowledge on nutrition’s role in health and disease for individuals and populations worldwide. Since its fiftieth anniversary in 2005, the Institute has initiated strategic planning to expand research and educational initiatives, alumni programs, fund-raising, and global dissemination of its nutrition education and intervention programs. For more information, please visit http://www.cumc.columbia.edu/dept/ihn/

Columbia University Medical Center provides international leadership in basic, pre-clinical and clinical research, in medical and health sciences education, and in patient care. The medical center trains future leaders and includes the dedicated work of many physicians, scientists, public health professionals, dentists, and nurses at the College of Physicians & Surgeons, the Mailman School of Public Health, the College of Dental Medicine, the School of Nursing, the biomedical departments of the Graduate School of Arts and Sciences, and allied research centers and institutions. Established in 1767, Columbia's College of Physicians & Surgeons was the first institution in the country to grant the M.D. degree and is among the most selective medical schools in the country. Columbia University Medical Center is home to the largest medical research enterprise in New York City and state and one of the largest in the United States. For more information, please visit www.cumc.columbia.edu.

Abstract

OBJECTIVE: We previously reported that saturated fat (SAT)-enriched diets increase arterial cholesteryl ester (CE) deposition, especially from LDL-selective uptake (SU), and this was associated with increased arterial lipoprotein lipase (LpL). We now question how n-3 fatty acid rich diets influence arterial cholesterol delivery and arterial LpL levels. METHODS AND RESULTS: C57BL/6 mice were fed chow or eucaloric high-fat diets enriched in SAT or fish oil (n-3) for 12 weeks, and then injected with double radiolabeled or fluorescent-labeled human LDL to separately trace LDL-CE and LDL-apoB uptake. SAT and n-3 diets increased plasma cholesterol levels similarly; n-3 diets lowered plasma triglyceride concentrations. SAT increased arterial LDL-SU with significantly higher CE infiltration into aortic media. In contrast, n-3 markedly reduced total LDL uptake and CE deposition and abolished SU with LDL localized only in aortic intima. Disparate patterns of CE deposition between diets were consistent with distribution of arterial LpL-SAT diets induced higher LpL levels throughout the aorta; n-3 diets decreased LpL levels and limited LpL expression to the aortic intima. CONCLUSIONS: n-3 rich diets decrease arterial total LDL delivery and abrogate LDL-SU in parallel with changing arterial wall LpL expression and distribution.

Reference:

Chang CL, Seo T, Matsuzaki M, Worgall TS, Deckelbaum RJ. n-3 Fatty Acids Reduce Arterial LDL-Cholesterol Delivery and Arterial Lipoprotein Lipase Levels and Lipase Distribution. Arterioscler Thromb Vasc Biol. 2009 Feb 5.

Columbia University Medical Center Released: Thu 05-Feb-2009

Key concepts: omega-3 fatty acids, EPA, DHA, fish oil, aorta, arteries