Less oxidative stress and lower incidence of cardiovascular disease with fish oil supplements

The beneficial action of Omega 3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) against cardiovascular disease may depend on their ability to reduce oxidative stress. This is shown by a study published by Free Radical Research, which found that daily intake of 4 grams of EPA or DHA for 6 weeks can reduce oxidative stress levels by about 20 percent.

The molecules involved in oxidative stress

The body naturally produces oxidizing molecules called reactive oxygen species. These substances play a key role in many processes, but an accumulation of them can become harmful. Certain circumstances, such as smoking habits, pollution, sun exposure, very strenuous physical activity or, simply, aging can promote an excessive production of reactive oxygen species, causing a situation known as oxidative stress. And oxidative stress can have very serious consequences, such as an increased risk of developing cancer, or Alzheimer 's disease or, again, various heart diseases. To test the benefits of Omega-3 intake in terms of oxidative stress, researchers from the University of Western Australia in Perth, Australia, and the University of Montpellier, France, have their effect on the accumulation of F2-isoprostanes. These molecules are derived from the peroxidation of arachidonic acid, an Omega-6 precursor of substances involved in inflammatory responses. This process is promoted by the presence of free radicals, molecules with high oxidizing power.

Omega-3 for heart and vessel health

The study involved overweight men with abnormal blood lipid levels and individuals with type-2 diabetes who were undergoing treatment to lower blood pressure. After having all participants take 4 grams per day of EPA, DHA or olive oil-which is not rich in Omega-3s-for 6 weeks, the researchers measured the levels of F2-isoprostanes in their urine. Analysis of the data obtained revealed that compared with olive oil, EPA reduced levels of these compounds by 24 percent in overweight men and 19 percent in diabetics. DHA, on the other hand, reduces F2-isoprostane concentrations by 14% in obese men and 23% in diabetics. Not only that, plasma levels of arachidonic acid are also reduced by both EPA and DHA. This, the authors explain, indicates that the effect of Omega-3s is due to true oxidation reduction.

Omega-3s counteract oxidative stress

The results obtained in this study disprove what was previously hypothesized. Indeed, the characteristic susceptibility of these fatty acids to oxidation had led experts to believe that omega-3s could increase levels of oxidative stress. But according to the research authors, the reduction in F2-isoprostanes observed in both obese individuals and diabetics indicates that these fats reduce oxidative stress. In addition, other studies, conducted, however, in healthy individuals, have also found the benefits of Omega-3s against oxidative stress. Taken together, these results show that the benefits of Omega-3s apply to both healthy individuals and those suffering from certain diseases. The new hypothesis formulated by the researchers is that this antioxidant effect is due, at least in part, to its anti-inflammatory action. In addition, the researchers explain, it is plausible that a reduction in the activity of a particular class of white blood cells, leukocytes, also comes into play. The authors conclude that these data further support the benefits of a diet enriched in omega-3 fatty acids for cardiovascular health.  

Source 

1. Mas E, Woodman RJ, Burke V, Puddey IB, Beilin LJ, Durand T, Mori TA, "The omega-3 fatty acids EPA and DHA decrease plasma F(2)-isoprostanes: Results from two placebo-controlled interventions," Free Radic Res. 2010 Sep;44(9):983-90