n-3 fatty acids induce oxidative modifications in human erythrocytes depending on dose and duration of dietary supplementation.
The present work was performed to study an optimal dose and duration of dietary n-3 polyunsaturated fatty acid (PUFA) supplementation that would not result in harmful modifications of oxidative cell metabolism. Forty healthy subjects were divided into four groups that received 2.5 g/d eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA), 5.1 g EPA + DHA/d, 7.7 g EPA + DHA/d, or placebo. Fatty acid composition, tocopherol status, and susceptibility to lipid peroxidation induced in vitro by 2,2'-azobis-(2-amidinopropane) (AAPH) were evaluated in human red blood cell (RBC) membranes on days 30 and 180. n-3 PUFA treatment increased EPA and DHA concentrations in RBC membranes in a time-dependent manner in all of the n-3 PUFA groups. These modifications occurred with concomitant dose- and time-dependent increases in the membrane unsaturation index. After 30 d of treatment with n-3 PUFAs, alpha-to-copherol significantly increased in RBC membranes of the intermediate- and high-dose groups. Because of the higher concentration of this antioxidant in these groups, the susceptibility of RBC membranes to peroxidation was decreased. However, after 180 d of treatment, alpha-tocopherol decreased to baseline values and AAPH-induced lipid peroxidation increased in a dose-dependent manner. These results show that high doses of dietary n-3 PUFAs, as well as long-time treatments, affect human RBC susceptibility to lipid peroxidation by changes in fatty acid composition and tocopherol content.
Palozza
P
P
Institute of General Pathology, Catholic University, Rome, Italy.
Sgarlata
E
E
Luberto
C
C
Piccioni
E
E
Anti
M
M
Marra
G
G
Armelao
F
F
Franceschelli
P
P
Bartoli
G M
GM
D000328:Adult; D000578:Amidines / Q000494:pharmacology; D004041:Dietary Fats / Q000494:pharmacology*; D004281:Docosahexaenoic Acids / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015118:Eicosapentaenoic Acid / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000187:drug effects* / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000097:blood / Q000494:pharmacology*; D005260:Female; D005527:Food, Fortified; D006801:Humans; D008054:Lipid Peroxides / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D013997:Time Factors; D014810:Vitamin E / Q000097:blood
D000578:Amidines; D004041:Dietary Fats; D015525:Fatty Acids, Omega-3; D008054:Lipid Peroxides; D014810:Vitamin E; D004281:Docosahexaenoic Acids; C046728:2,2'-azobis(2-amidinopropane); D015118:Eicosapentaenoic Acid