Fish oil supplements could help reduce fatty substances such as the bad cholesterol in the blood of people with diabetes, but not in people without the condition, according to researchers reporting in the October issue of Diabetes Care.
The Danish scientists maintained that as people with type 2 diabetes have high levels of fat in their blood, as well as lower levels of HDL ("good") cholesterol, the results suggest that diabetics could "partially correct" their condition with the addition of fish oils to their diet.
The study involved 42 adults with type 2 diabetes who were randomised to take either a 4g daily supplement of fish oil or a similar capsule of corn oil for 8 weeks preceded by a 4-week run-in period of corn oil supplementation. Blood was drawn before and after the 8-week intervention period. Plasma lipoproteins, including LDL and HDL subclasses, were separated by ultracentrifugation.
The researchers found that those who took the fish oil supplement for eight weeks lowered their levels of triacylglycerol (TAG), a fatty substance linked to heart disease. Both HDL-2b cholesterol and HDL-2a cholesterol (two sub-types of 'good' cholesterol) rose compared to those taking the corn oil. The ratio of LDL to HDL fell by nearly 1 per cent among patients taking fish oil supplements, and rose 4 per cent among those taking corn oil.
However the team observed no significant effects of fish oil on LDL cholesterol, HDL cholesterol, or the concentration of small dense LDL particles, linked to symptoms of heart disease.
The researchers concluded: "Fish oil supplementation may partially correct the dyslipidemia (abnormal blood fats) of type 2 diabetic patients. However, the very important aspect of diabetic dyslipidemia - the predominance of small dense LDL particles - was unaffected by fish oil."