http://www.springerlink.com/content/vt413114v8v63011/最近研究发现呼吸或通过饮水摄取氢气可以中和机体内的活性氧，如羟基自由基，从而通过降低氧化应激诱导的脑、心脏等器官损伤对各种疾病产生保护作用。这些研究认为外源性氢气会与自由基反应，从而被机体“利用”。本研究主要是评价饮用含氢气水后氢气被机体消耗的量。7名成年受试者饮用氢气水后，采用气相色谱半导体检测呼吸气体中氢气的含量。呼吸气体中氢气的水平饮水后10分钟迅速升高到36 ppm。然后迅速在60分钟内下降到正常水平，采用呼吸时间和浓度计算出氢气释放的总数量大概为吸收氢气的59%。试验过程中氢气的泄露大概3%以下。通过皮肤释放的氢气不到0.1%。因此大概有40%的氢气被保留在身体内。由于氢气属于弱还原剂量，只能和羟基自由基发生中和反应，因此可以推断身体内产生羟自由基的速度低于1.0 μmol/min/m^2.

     这个研究工作没有太多的研究证据，只根据一组人体呼吸气体氢气浓度的检测推断出身体内羟基自由基的产生速度。恐怕太大胆了。

本人提出质疑如下：

一、        氢气还原性弱，只能和羟基自由基反应，但不能排除羟基自由基和其他物质发生反应。氢气进入身体很难和比氢气还原性强的物质进行竞争。因此不能利用氢气被“消耗”的量来判断羟基自由基的产生速度。另外氢气也可能和其他活性强的自由基反应，也不能完全归因于羟基自由基。

二、        氢气摄取和释放应该符合气体运行规律，身体内不同组织溶解和释放氢气的速度完全不同。不同性质的组织溶解氢气的能力也不同。因此难以从整体上分析氢气的保留数量。身体的成分复杂，气体进入身体内，特别是少量气体，很容易被一些分子黏附，这些气体并不是被中和，而是长时间存在于身体内。这类似于把气体通入粘稠的液体中。气体只是物理隔离在液体中而已，并没有被利用。

三、        经过皮肤释放的数量可能不准确。氢气比其他气体分子量小，更容易扩散，更容易经过皮肤扩散。

四、        成年身体内本身存在一定数量的氢气，如何排除干扰。

五、        试验的设计太过简单，例如反复试验多次，看前面保留在身体的氢气是否会影响后来的氢气释放数量。应该设计不同的剂量，看不同剂量的释放和保留是否有规律。

六、        15年前，有学者曾经用动物试验和氢同位素标记都没有证明氢气被身体利用。而现在采用的技术分辨率远低于同位素标记。竟然说有那么多氢气被利用。别说氢气，许多药物都很难被利用40%。而且氢气进入身体只有几分钟时间，更不可能被利用那么多。

Recent studies have revealed that inhaled or ingested hydrogen gas (H₂) inactivates reactive oxygen species such as hydroxyl radicals in various kinds of diseases and disorders in animal models and that H₂ reduces oxidative stress-induced damage in brain, heart, and other peripheral tissues. These reports suggested that exogenous H₂ is partially trapped by oxygen radicals. This study was conducted to evaluate H₂ consumption after the ingestion of H₂-rich water. Seven adult subjects ingested H₂-rich water. The H₂ content of their expired breath was measured by gas chromatography with a semiconductor. The ingestion of H₂-rich water rapidly increased breath H₂ content to its maximal level of approximately 36 ppm at 10 min after ingestion and thereafter decreased it to the baseline level within 60 min. Taken together with simultaneous measurements of expiratory minute volume, 59% of the ingested H₂ was exhaled. The loss of H₂ from the water during the experimental procedures accounted for 3% or less of the H₂. H₂ release from the skin surface was estimated as approximately 0.1%. Based on the remaining H₂ mass balance, approximately 40% of the ingested H₂ was consumed in the body. As the H₂ molecule is reported to be a weak scavenger of hydroxyl radicals and is not effective against superoxide or hydrogen peroxide, the rate of hydroxyl radical production was estimated to be at least 1.0 μmol/min/m² (equivalent to 29 nmol/min/kg), assuming that the H₂ molecules were all used to scavenge hydroxyl radicals and that bacterial consumption in the alimentary tract and on the skin surface could be excluded. In summary, 59% of ingested H₂ was exhaled, and most of the remainder was consumed in the body.