12 August 2013
ByAppeared in BioNews 717
The review looked at 'subfertile' women, defined as those that have been trying to conceive for over a year with no success. Around a quarter of couples experience trouble conceiving, and although the exact causes in each case are often poorly understood, female disorders such as poor egg quality, fallopian tube damage and endometriosis are thought to be responsible in 40 to 50 percent of couples.
Antioxidants are substances that mop up free radicals in the body, and they are thought to reduce oxidative stress associated with some of these conditions. Many infertile women turn to over-the-counter antioxidant supplements such as vitamin C and vitamin A to try and increase their chances of conceiving.
But a meta-analysis of 28 trials, involving a total of 3,548 women, concluded that women taking either individual or combinations of antioxidant pills were no more likely to conceive than those fed placebos or other dietary supplements such as folic acid.
'There is no evidence in this review that suggests taking an antioxidant is beneficial for women who are trying to conceive', said lead researcher Marian Showell from the University of Auckland.
She added that the general quality of trial evidence the review had looked at was poor, and that it was difficult to draw comparisons between different antioxidants, as lots of different substances had been included. The review also looked for evidence of adverse effects of antioxidants, such as ectopic pregnancy or miscarriage, but found no evidence to cause concern.
'I don't think the results were surprising in the sense that there are no national organisations or guidelines that recommend routine use of antioxidant supplements for fertility', Dr Wendy Vitek, a fertility researcher at the University of Rochester who was not involved in the review, told The Huffington Post. She added, however, that the findings are disappointing: 'It would make everyone's lives easier if we could say, "here, take this supplement"'.