International Health News: Fish and Fish Oil - Comprehensive listing of well-written research abstracts categorized by disease and health condition. Topics include: Atherosclerosis, Arrhythmias/Cardiac Arrest, Hypertension, Breast/Prostate Cancer, Rheumatoid Arthritis, Psoriasis, Emphysema/Cystic Fibrosis, Kidney Disorders, Attention Deficit Disorder, Stroke/Blood Coagulation, Angina/Heart Attack, Cholesterol/Triglycerides, Cancer, Diabetes, Inflammatory Bowel Disease, Asthma, Pregnancy and Infants, Menstrual Cramps, Mental Health/Depression/Dementia, Diet/Weight Control.
Fish oil can help reduce deaths from heart disease, according to evidence reports released in April 2004 by the Agency for Healthcare Research and Quality (AHRQ) in Rockville, MD. The systematic reviews of the available literature found evidence that long-chain omega 3 fatty acids, the beneficial component ingested by eating fish or taking a fish oil supplement, reduce heart attack and other problems related to heart and blood vessel disease in people who already have these conditions, as well as their overall risk of death.
Although omega-3 fatty acids do not alter total cholesterol, HDL cholesterol or LDL cholesterol, evidence indicates that fish oil can
help lower high blood pressure slightly,
may reduce risk of coronary artery re-blockage after angioplasty,
may increase exercise capability among patients with clogged arteries, and
may possibly reduce the risk of irregular heart beats, particularly in individuals who have had a recent heart attack.
"These findings will help health care professionals and the public understand which benefits of omega-3 fatty acids have been scientifically proven and pinpoint areas where additional evidence is needed," said Carolyn M. Clancy, M.D., AHRQ director. "Translating scientific evidence into information that can be used to improve health and health care is key to AHRQ's mission."
The evidence reports of the health effects of omega-3 fatty acids are part of a series conducted by AHRQ-supported Evidence-based Practice Centers at the request of the National Institutes of Health (NIH) Office of Dietary Supplements (ODS), which plans to use the findings to develop research agendas on the issues. Five reports are currently being issued, and an additional six reports will be issued next year.
Paul M. Coates, Ph.D., director of NIH's Office of Dietary Supplements, said, "The reports describe some positive findings as well as a number of areas where data are insufficient to draw conclusions about the efficacy and safety of omega-3 fatty acids. The Office of Dietary Supplements, in collaboration with other NIH institutes, will use these reports to develop appropriate research agendas for omega-3 fatty acids that will fill these gaps in knowledge."
Findings from the three other AHRQ evidence reviews indicate that:
Omega-3 fatty acids do not affect fasting blood sugar or glycosylated hemoglobin in people with type II diabetes, nor do they appear to affect plasma insulin levels or insulin resistance.
Alpha-linolenic acid (ALA), a type of omega-3 fatty acid from plants such as flaxseed, soybeans, and walnuts, may help reduce deaths from heart disease, but to a much lesser extent than fish oil.
Based on the evidence to date, it is not possible to conclude whether omega-3 fatty acids help improve respiratory outcomes in children and adults who have asthma.
Omega-3 fatty acids appear to have mixed effects on people with inflammatory bowel disease, kidney disease and osteoporosis, and no discernible effect on rheumatoid arthritis.
The evidence reports and Evidence-based Practice Centers that produced them are: Effects of Omega-3 Fatty Acids on Cardiovascular Disease, Effects of Omega-3 Fatty Acids on Cardiovascular Risk Factors and Intermediate Markers for Cardiovascular Disease, and Effects of Omega-3 Fatty Acids on Arrhythmogenic Mechanisms in Animal and Isolated Organ/Culture Studies (Tufts-New England Medical Center EPC, Boston); Health Effects of Omega-3 Fatty Acids on Asthma (University of Ottawa EPC, Ottawa, Ontario); Health Effects of Omega-3 Fatty Acids on Lipids and Glycemic Control in Type II Diabetes and the Metabolic Syndrome, and on Inflammatory Bowel Disease, Rheumatoid Arthritis, Renal Disease, Systemic Lupus Erythematosus, and Osteoporosis (Southern California-RAND EPC, Santa Monica).
Summaries of evidence reviews are available on AHRQ's Web site at http://www.ahrq.gov/clinic/epcindex.htm#dietsup, and on the National Guideline Clearinghouse Web site at http://www.guideline.gov (select "EPC reports"). Free printed copies are available from the AHRQ Publications Clearinghouse by calling 1-800-358-9295 or sending an e-mail to firstname.lastname@example.org.
AHRQ Evidence Reports Confirm that Fish Oil Helps Fight Heart Disease. Press Release, April 22, 2004. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/news/press/pr2004/omega3pr.htm