Professor Donald Jump and his co-workers report that fish consumption and omega-3 supplements may still help reduce the risk of heart disease, and that some fatty acids, from certain sources, are more effective than others.
The heart health benefits of fish oil, and the omega-3 fatty acids it contains, are well-documented, being first reported in the early 1970s by Dr Jorn Dyerberg and his co-workers in The Lancet and The American Journal of Clinical Nutrition.
To date, the polyunsaturated fatty acids (PUFAs) have been linked to improvements in blood lipid levels, a reduced tendency of thrombosis, blood pressure and heart rate improvements, and improved vascular function.
Discrepancies
Writing in the Journal of Lipid Research, the researchers note that recent studies may have reported ‘less conclusive’ data because of the very effectiveness of modern drug therapies for heart disease.
“It’s less clear how much impact fish oils have in preventing further cardiovascular events in people who already have heart disease,” said Jump.
“The studies done several decades ago showed value even for that patient population, but the more recent studies are less conclusive. We believe that one explanation is the effectiveness of current state-of-the-art treatments now being offered.”
Jump noted that some of the early studies done on fish oil were prior to so many effective medications being widely available and heavily used. “And people often forget that nutrients, like fish oils, are less potent than prescription drugs, and often have their best value when used for extended periods,” he added.
“When so many people in these studies are taking a regimen of medications to address the same issues that fish oil might also affect, it’s easy to understand why any added benefit from the fish oils is more difficult to detect.”
Other key findings from the review include:
- Plant-derived sources of these fatty acids, such as flaxseed oil or chia seeds, have less benefit than those from cold-water fish, because of differences in how the human body processes these nutrients.
- For individuals unwilling or unable to consume fish or fish-oil supplements, some products made from yeast or algae are high quality.
“We still believe the evidence is strong that the EPA and DHA content in heart tissues and blood is important to health and to the prevention of cardiovascular disease,” Jump said. “To meet the current recommendations for primary prevention of cardiovascular disease, individuals are advised to consume 200-300 milligrams of combined EPA and DHA per day.”
The research was supported by the US Department of Agriculture and the National Institutes of Health.
Commenting on the review, Harry Rice, PhD, VP of scientific and regulatory affairs for GOED, the omega-3 trade association, told NutraIngredients-USA: “I think the authors' conclusion that non-fish sources of n-3 PUFA vary in their capacity to regulate blood levels of EPA & DHA and CVD risk factors is premature.
“I think it's more likely that there's a variation in how long it takes to equilibrate those levels, and in the long-term, the ramp-up stage is of little significance.”
Source: Journal of Lipid Research
2012, Volume 53, Number 12, Pages 2525-2545
“Omega-3 fatty acid supplementation and cardiovascular disease: Thematic Review Section: New Lipid and Lipoprotein Targets for the Treatment of Cardiometabolic Diseases”
Authors: D.B. Jump, C.M. Depner, S. Tripathy