紐西蘭研究人員發現，男性服用維生素E和鋅等抗氧化劑或許能增強生育能力。
提觀點
紐西蘭奧克蘭大學研究人員把研究對象鎖定為生育能力低的男性，即生育能力低於平均水平但仍能生育。
統計結果顯示，每20名男性中會有一人承受低生育能力困擾，夫婦晚育一半源於男性生育能力低。醫學專家認為，男性生育能力低80%是因為精子受到氧化，數量減少，質量降低。
精子氧化由一種名為自由基的分子引發。自由基是細胞新陳代謝產物，具有強氧化性，可損傷機體組織和細胞功能。抗氧化劑含有某些維生素和營養成分，能夠幫助細胞抵禦自由基損傷。
一些學者設想，男性服用抗氧化劑或許能夠幫助精子保持遊動能力。研究人員回顧以往生殖研究，希望獲得數據，支持這一觀點。
溯研究
研究人員回顧34項生育治療研究，涉及近3000對夫婦。治療方法包括體外受精和宮腔內人工受精，即兩種針對男性精子質量低所致不孕症的最常用方法。
分析15項研究中96個成功受孕案例，研究人員發現，男性服用抗氧化劑後，生育能力增強4倍多，配偶分娩活胎的可能性增加5倍。
研究項目主管瑪麗安·肖維爾說：「口服抗氧化劑可能在一定程度上提高夫妻受孕機率。」
研究報告由網上醫學電子雜誌《科克倫圖書館》 The Cochrane Library 發表。不過，研究人員認為，抗氧化劑增強男性生育能力的觀點並非絕對正確，有待更多研究結果加以確認。
遭質疑
這項研究遭到一些生育專家質疑。美國伊利諾伊大學泌尿學教授勞倫斯·羅斯說：「男性精子功能存在障礙，不查明原因而單純藉助抗氧化劑施行治療不合適。」
另一些專家質疑研究方法和研究對象數量。研究人員回顧的34項研究中，沒有一項研究的參與人數超過1000人，一些研究僅10人參與。
美國布朗大學教授馬克·西格曼說：「研究表明，抗氧化劑能夠提高嬰兒安全出生可能性，這一結論僅以20個案例為依據，樣本數量相對較少。」他認定，研究涉及的抗氧化劑種類和數量不同，無法確定每一種抗氧化劑的效用。
「一種治療方法對多數夫妻有效的想法不現實，」西格曼說，「雖然沒有證據表明抗氧化劑有害人體健康，但我們不清楚哪一種抗氧化劑或者多少劑量能夠增強生育能力，沒有一種抗氧化劑獲得（美國）食品和藥物管理局批准用於不孕不育症治療，消費者不應該偏聽偏信。」（生物谷Bioon.com）
生物谷推薦原文出處：
Cochrane Database of Systematic Reviews 2011, Issue 1. Art. No.: CD007411. DOI: 10.1002/14651858.CD007411.pub2.
Antioxidants for male subfertility
Marian G Showell1, Julie Brown1, Anusch Yazdani2, Marcin T Stankiewicz3, Roger J Hart4
1Obstetrics and Gynaecology, University of Auckland, Auckland, New Zealand. 2Clinical Research and Development, Queensland Fertility Group, Woolloongabba, Australia. 3Reproductive Medicine, Flinders Reproductive Medicine, Bedford Park, Australia. 4School of Women's and Infants Health, The University of Western Australia, King Edward Memorial Hospital and Fertility Specialists of Western Australia, Subiaco, Australia
Abstract
Background
Between 30% to 80% of male subfertility cases are considered to be due to the damaging effects of oxidative stress on sperm. Oral supplementation with antioxidants may improve sperm quality by reducing oxidative stress.
Objectives
This Cochrane review aimed to evaluate the effect of oral supplementation with antioxidants for male partners of couples undergoing assisted reproduction techniques (ART).
Search strategy
We searched the Cochrane Menstrual Disorders and Subfertility Group Register, CENTRAL (The Cochrane Library), MEDLINE, EMBASE, CINAHL, PsycINFO and AMED databases (from their inception until Febuary 2010), trial registers, sources of unpublished literature, reference lists and we asked experts in the field.
Selection criteria
We included randomised controlled trials comparing any type or dose of antioxidant supplement (single or combined) taken by the male partner of a couple seeking fertility assistance with placebo, no treatment or another antioxidant. The outcomes were live birth, pregnancy, miscarriage, stillbirth, sperm DNA damage, sperm motility, sperm concentration and adverse effects.
Data collection and analysis
Two review authors independently assessed studies for inclusion and trial quality, and extracted data.
Main results
We included 34 trials with 2876 couples in total.
Live birth: three trials reported live birth. Men taking oral antioxidants had an associated statistically significant increase in live birth rate (pooled odds ratio (OR) 4.85, 95% CI 1.92 to 12.24; P = 0.0008, I2 = 0%) when compared with the men taking the control. This result was based on 20 live births from a total of 214 couples in only three studies.
Pregnancy rate: there were 96 pregnancies in 15 trials including 964 couples. Antioxidant use was associated with a statistically significant increased pregnancy rate compared to control (pooled OR 4.18, 95% CI 2.65 to 6.59; P < 0.00001, I2 = 0%).
Side effects: no studies reported evidence of harmful side effects of the antioxidant therapy used.
Authors' conclusions
The evidence suggests that antioxidant supplementation in subfertile males may improve the outcomes of live birth and pregnancy rate for subfertile couples undergoing ART cycles. Further head to head comparisons are necessary to identify the superiority of one antioxidant over another.