The research, published in The Journal of Nutrition, suggests that the effects of metabolic syndrome – a major risk factor for insulin resistance and diabetes - can be reduced through the addition of omega-3 fatty acids in low-fat, high-complex carbohydrate diets.
“Fish oil supplements correct many metabolic alterations associated with insulin resistance, including reduced postprandial plasma triglyceride concentration” stated the researchers, led by Jose Lopez-Miranda from the University of Cordoba, Spain.
Metabolic syndrome is the name given to a group of risk factors that frequently include obesity, hypertension, high levels of blood lipids, and high blood sugars.
The condition is a common precursor to type II diabetes, and is also strongly associated with increased risk of major health problems such as heart disease and stroke.
The causes of metabolic syndrome are unknown, although they are thought to involve both genetic and environmental factors – including poor diet.
One way to increase the overall health – and reduce the risks - of people with metabolic syndrome, has been to eat a diet low in saturated fat and high in complex carbohydrates. However, previous research has suggested that this diet does not help to reduce high levels of blood lipids - with some studies observing such a diet could even be raising blood lipid levels.
The new study looked into the effects of four different diet combinations on blood lipid metabolism, in 117 patients with metabolic syndrome.
In accordance with previous suggestions, the researchers found that a low-fat, high-complex carbohydrate diet had “several detrimental effects”, including significantly increasing total triglyceride levels, and triglyceride rich lipoprotein cholesterol levels.
In contrast, intake of the same diet supplemented with omega-3 was found to have no effects on blood lipid levels, with researchers observing that a diet rich in monounsaturated fats, or a low-fat diet rich in complex carbohydrates and omega-3 fatty acids, resulted in lower circulating blood lipid levels than a diet rich in high saturated fats or a diet low in fats and high in complex carbohydrates.
The data from the study suggest a place for higher omega-3 intake in people with metabolic syndrome, and supports previous research that suggests monounsaturated fatty acids can have a positive effect on blood lipid levels.
"The long-term effect of the low-fat, high-complex carbohydrate diet, pre vs. post intervention phases, showed several beneficial effects of long chain omega-3 PUFA supplementation,” stated the researchers.
“Our data suggest that long-term intake of an isocaloric, low-fat, high-carbohydrate diet supplemented with long chain omega-3 … have beneficial effects on postprandial lipoprotein response in patients with metabolic syndrome,”
Source: The Journal of Nutrition
Published online ahead of print, doi:10.3945/jn.109.120816
“A Low-Fat, High-Complex Carbohydrate Diet Supplemented with Long-Chain (n-3) Fatty Acids Alters the Postprandial Lipoprotein Profile in Patients with Metabolic Syndrome”
Authors: Y. Jimenez-Gomez, C. Marin, P. Perez-Martinez, et al