The supply status for omega-3 fatty acids may be influenced by gender

A new study from Australia reports that an increase of blood omega-3 fatty acid concentration by fish oil intake seems to be more effective in females and at concurrent vitamin/mineral supplementation.

In the randomized controlled trial, the omega-3 and omega-6 fatty acid concentrations were measured in red blood cells of 160 healthy adult participants, aged between 50 to 70 years, who received either 6 g of fish oil (480 mg EPA and 480 mg DHA), 6 g of fish oil plus a multivitamin, 3 g of fish oil (240 mg EPA and 240 mg DHA) plus a multivitamin or a placebo daily for 16 weeks (1). The study results showed that the treatment with 6 g of fish oil led to a higher eicosapentaenoic acid (EPA) concentration in blood compared to the intake of 3 g fish oil, while docosahexaenoic acid (DHA) intakes had no effect on red blood cell composition. The omega-3 (EPA plus DHA) to omega-6 fatty acid (arachidonic acid, AA) ratio and the total omega-3 fatty acid (EPA plus DHA) concentration was only higher, compared to placebo, in the participant group receiving the combination of 6 g of fish oil and the multivitamin supplement. Analysis by gender revealed that all treat- ments increased EPA incorporation in females while, in males, EPA was only significantly increased by the 6 g fish oil multivitamin combination. There was considerable individual variability in the red blood cell incorpo- ration of EPA and DHA. Gender contributed to a large proportion of this variability with females generally showing higher blood omega-3 fatty acid concentrations after fish oil intake.

The researchers commented that recent studies suggested that males and females respond differently to omega-3 fatty acid supplementation across different health parameters (2, 3). Males and females may there- fore differ in their ability to incorporate omega-3 fatty acids into erythrocytes. Some males may incorporate relatively low amounts of omega-3 fatty acids into red blood cells despite adhering to intake guidelines, the scientists concluded. Moreover, some vitamins/minerals may aid the incorporation of omega-3 fatty acids into red blood cells: as cofactors vitamins, such as B vitamins, and minerals seem to influence the biosynt- hesis of omega-3 fatty acids, altering their blood levels (4). On the other hand, low levels of antioxidant vitamins may increase the risk of oxidative damaging (peroxidation) of lipids. As vitamin E (alpha-tocop- herol) is vital to the prevention of polyunsaturated fatty acid (PUFA) oxidation in cell membranes, it has been calculated that the intake requirement for alpha-tocopherol for PUFA protection is 12 to 14 mg per day (5). By preserving intracellular and cellular membrane integrity and stability, vitamin E plays an important role in the stability of red blood cells and conductivity in central and peripheral nerves (6).

1. Pipingas A. et al. Randomized Controlled Trial Examining the Effects of Fish Oil and Multivitamin Supplementation on the Incorporation of n-3 and n-6 Fatty Acids into Red Blood Cells. Nutrients. 2014; 6:1956–1970.
   
2. Phang M. et al. Eicosapentaenoic and docosahexaenoic acid supplementations reduce platelet aggregation and hemostatic markers differentially in men and women. J. Nutr. 2013;143:457–463.
   
3. Stonehouse W. et al. DHA supplementation improved both memory and reaction time in healthy young adults: A andomized controlled trial. Am. J. Clin. Nutr. 2013; 97:1134–1143.
   
4. Bertrandt J. et al. Content of polyunsaturated fatty acids (PUFAs) in serum and liver of rats fed restricted diets supplemented with vitamins B2, B6 and folic acid. BioFactors. 2004; 22:189–192.
   
5. Deutsche Gesellschaft für Ernährung, Ö.G.f.E., Schweizerische Gesellschaft für Ernährungsforschung, Schweizerische Vereinigung für Ernährung. Referenzwerte für die Nährstoffzufuhr. 2008; pp 87–93. Neuer Umschau Buchverlag, Neustadt an der Weinstraße.
   
6. Boda V. et al. Monitoring erythrocyte free radical resistance in neonatal blood microsamples using a peroxyl radical-mediated haemolysis test. Scand. J. Clin. Lab. Invest. 1998; 58:317–322.