理君博士：“支链氨基酸”将引爆抗衰老保健品市场

前些日子看到一篇由Richard Alleyne撰写的文章《A genuine‘elixiroflife’》，说实话，读完以后我有些兴奋，它预示我们：新型“长生不老药”即将问世！从古至今人类一直都在追求长生不老，如今这个梦想似乎不再遥不可及了。英国《每日电讯报》本月5日也刊出同样报道：科学家发现了一种能够延年益寿的药物，而且已经在小白鼠身上进行实验，并获得成功，人类首次证明了氨基酸混合物能够延长寿命，支链氨基酸将全面改写抗衰老学说，也将全面引爆抗衰老保健品及药品市场。

原文如下：

A genuine ‘elixir of life’

      In laboratory experiments, middle-aged male healthy mice were given drinking water laced with three specific amino acids.

      The animals lived significantly longer than other mice fed a normal diet.

      Their lifespan range had a midpoint of 869 days compared with 774 days for untreated mice, a difference of 12 per cent.

      Longer survival was accompanied by biological changes which boosted the energy supply to cells and reduced oxidative damage caused by destructive molecules called free radicals.

      The treated mice had more stamina and improved muscle co-ordination.

      "This is the first demonstration that an amino acid mixture can increase survival in mice," said study leader Dr Enzo Nisoli, from the University of Milan in Italy.

      Last year scientists showed that the same amino acids, leucine, isoleucine and valine, could extend the lifespan of single-celled yeast.

      The new findings, reported in the journal Cell Metabolism, raise the possibility of amino acid supplements benefiting humans.

      The scientists pointed out that the mice studied were aged but otherwise healthy.

      They believe taking the amino acids might be especially helpful for the elderly or ill, particularly people with heart failure, chronic lung disease, or other conditions characterised by flagging energy levels.

      Dr Nisoli said a large patient trial was needed to provide evidence convincing enough for doctors. However, there was little financial incentive for companies to conduct such studies on dietary supplements.

      Leucine, isoleucine and valine, known as branched-chain amino acids (BCAAs), account for a fraction of the 20 amino acids from which proteins are made, but appear to have special anti-ageing properties.

      Mice given the three amino acids produced larger numbers of mitochondria - the rod-like "powerhouses" in cells that generate energy - in their heart and skeletal muscle.

      They also showed increased activity of SIRT1, a well-known longevity gene, and developed better defences against free radicals.

BCAA nutritional supplements are readily available in health food stores and online.

      Amino acid supplements were likely to be more effective than consuming proteins containing the same amino acids, according to the researchers.

      Unlike protein, they did not have to be digested, and could enter the bloodstream immediately.

      "They come with no energy cost," said Dr Nisoli.

      In their paper the scientists wrote: "We have provided evidence that an original BCAA mixture increases average life span in male mice.

      "This was likely the consequence of increased mitochondrial biogenesis and reduced oxidative stress in cardiac and skeletal muscles.

      Our study offers a rationale for deeply exploring the role of amino acids in prevention and

control of age-related disorders in humans."

这种神奇的药物就是由亮氨酸、异亮氨酸和缬氨酸这3种氨基酸组成的混合物，学名“支链氨基酸”。

支链氨基酸（branchedchainaminoacid，BCAAs），是一种十分重要和有效的营养补剂，其侧链具有分支结构的氨基酸。在蛋白质中常见的有苏氨酸、缬氨酸和异亮氨酸等，它可以帮助生物体自然地、没有任何副作用地增强肌肉或获得更多能量。

对于我们长期研究保健品研究的人来说，支链氨基酸并不陌生，最初我们认为支链氨基酸对任何运动的人群来说都是最重要和最有效的营养补剂。这点非常重要，那就是如果你想要自然地、没有任何副作用地来增加肌肉或获得更多能量，那你就要考虑使用支链氨基酸了。支链氨基酸以两种特殊方式促进合成代谢（肌肉增长）：

①     释放胰岛素；

②     释放生长激素。

支链氨基酸中最重要的是亮氨酸，即酮异己酸（KIC）和HMB的前身。KIC和HMB可增加肌肉肉，减少脂肪，并为人体提供营养。乳清蛋白的BCAA含量较高。运动训练后应补充4－5克。支链氨基酸可以通过血流进入大脑，降低大脑的5羟色胺的产生，而5羟色胺可使人产生疲倦感。通过减少5羟色胺的含量可减轻脑力疲劳。当你在想练就出更强壮、更有力的身体时，在细胞水平上刺激和给你的肌肉供能是必要的，支链氨基酸组成几乎1/3肌肉蛋白。BCAAs能减缓肌肉疲劳，加速恢复，降低运动时其它氨基酸从肌肉中的丢失，并有助于机体吸收蛋白质。缺乏其中三者之一将导致肌肉丢失。不象其它氨基酸，BCAAs在肌肉中代谢，而不是在肝脏。支链氨基酸之间在吸收能力上具有相互竞争性，因此必须同时补充，以保证最大程度的吸收。训练时肌肉中支链氨基酸的消耗也是很快的，运动前或运动中补充支链氨基酸可以提高运动能力和延缓疲劳。运动后或运动后随餐服用支链氨基酸可以降低皮质醇（损害肌肉的罪魁祸首）和快速恢复肌肉中支链氨基酸的水平。支链氨基酸作为氮的载体，辅助合成肌肉合成所需的其它氨基酸，简单说，它是一个简单氨基酸合成复杂完整肌肉组织的过程。因此，支链氨基酸刺激胰岛素的产生（胰岛素的主要作用就是允许外周血糖被肌肉吸收并作为能量来源），胰岛素的产生也促进肌肉对氨基酸的吸收。支链氨基酸既有合成作用，也有抗分解作用，因为它们可以显著增加蛋白合成，促进相关激素的释放，如生长激素（GH、IGF-1胰岛素样生长因子-1）和胰岛素以及有助于维持一个合理的睾酮及皮质醇比例。

当然，这些都是我们以往对支链氨基酸的研究课题，现如今，支链氨基酸不仅仅是一种运动后的营养添加剂，它还将全面改写抗衰老学说，也将全面引爆抗衰老保健品及药品市场。这项研究的主要研究员是来自意大利米兰大学的恩佐·尼索里教授，他还指出，如果在此基础上发明氨基酸补剂，那么它在未来造福人类，对于老年人或病人有很大帮助，尤其是那些患有以细胞能级降低为特征的疾病的人，比如心力衰竭或慢性肺病患者等。

研究人员在实验过程中，给被试小白鼠喝的水里加入了这3种氨基酸，结果发现它们的寿命平均达到了869天，而普通小白鼠最高则只能存活大约774天。也就是说，“支链氨基酸”使小白鼠的生命延长了12%。在延长寿命的同时，小白鼠的机体内还发生了一系列积极的生物反应，比如细胞得以摄取更多的能量、自由基减少等。（自由基是机体氧化反应中产生的有害化合物，具有强氧化性，可损害机体的组织和细胞，进而引起慢性疾病及衰老效应。）经过这些体内变化，小白鼠看起来充满活力，而且肌肉协调能力有所提高。科学家已经发现这种氨基酸混合物在延长单细胞酵母寿命上的巨大作用。