Web edition: June 12, 2012
Ingredients in fish oil widely considered to have heart-healthy powers may not deliver in some people. People with type 2 diabetes, including many with a history of heart disease or hypertension, don’t seem to get a cardiovascular benefit from omega-3 fatty acids, the key ingredients in fish oil, researchers report June 11 in the New England Journal of Medicine.
“This is surprising,” says Paul Marik, a physician and nutritionist at Eastern Virginia Medical School in Norfolk. “Why it didn’t show a benefit is unclear.” Previous research has suggested that fish oil can also help against depression, sepsis, cancer, joint pain and neurological disorders. “I’m not sure that, based on this study, we should throw fish oil out the window,” Marik says.
The omega-3 fatty acids in fish oil lower blood levels of triglycerides, which have been linked to cardiovascular disease.
For the international study, Jackie Bosch, a medical epidemiologist at McMaster University in Hamilton, Ontario, and colleagues tracked 12,536 people with type 2 diabetes or prediabetic conditions who had been randomly assigned to take capsules of omega-3s or olive oil. Although people getting the omega-3s saw their triglyceride levels improve substantially more than those getting olive oil, people in the omega-3 group were no more or less likely to die of heart problems or even develop them. About 9 percent of people in the six-year study died of a heart ailment, regardless of their study group.
When no difference emerged between the groups, Bosch acknowledged being disappointed but says diabetes patients might represent a special group.
“We’re seeing that the population being studied actually matters,” she says.
ORIGIN Trial investigators. N-3 fatty acids and cardiovascular outcomes in patients with dyslipidemia. New England Journal of Medicine. doi: 10.1056/NEJMoa1203859. [Go to]
P. Marik and M. Flemmer. Do dietary supplements have beneficial health effects in industrialized nations? What is the evidence. Journal of Parenteral and Enteral Nutrition, Volume 36, March 2012, p. 159. doi: 10.1177/0148607111416485.
N. Seppa. Fish oil fails to hold off heart arrhythmia. Science News. Volume 178, December 18, 2010, p. 15. Available online: [Go to]
N. Seppa. Fish oil may fight breast cancer. Science News. Volume 178, July 31, 2010, p. 13. Available online: [Go to]
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