Magnesium May Not Reach Your Brain, Despite Supplement Label Promises

Title: Magnesium May Not Reach Your Brain, Despite Supplement Label Promises

Most of us probably don’t think about how much magnesium we’re consuming, but our bodies couldn’t function without it. We each typically contain about 25 grams of magnesium, more than half of which is stockpiled in bones. The rest is distributed in cells throughout the body, taking part in hundreds of essential chemical reactions, including building DNA and proteins and sending signals within our nervous systems and between our brains and the rest of our bodies.

我们大多数人可能不会考虑自己摄入了多少镁，但没有它，我们的身体就无法正常运作。我们每个人体内通常含有约 25 克镁，其中一半以上储存在骨骼中。其余部分分布在全身的细胞中，参与数百种重要的化学反应，包括构建 DNA 和蛋白质，以及在我们的神经系统内部以及大脑与身体其他部位之间传递信号。

But just because our cells—and especially our neurons—need magnesium doesn’t mean that extra magnesium will make them function any better. Not only that, but ingesting more of the element doesn’t mean it’s reaching your brain or really any specific part of your body.

但仅仅因为我们的细胞——尤其是神经元——需要镁，并不意味着额外的镁就能让它们发挥更好的功能。不仅如此，摄入更多的这种元素并不意味着它能到达你的大脑或身体的任何特定部位。

In supplement pills, magnesium isn’t just on its own but part of a compound usually called a “magnesium salt.” This must dissolve to release Mg²⁺, the ionic version that our bodies use. How much of this actually gets into your system—versus gets excreted—depends on a variety of factors including the dose, your stomach contents, and how much magnesium is already in your body. In other words, the higher the dose, the less magnesium gets absorbed.

在补充剂药丸中，镁并非单独存在，而是通常被称为“镁盐”的化合物的一部分。它必须溶解才能释放出我们身体所使用的离子形式 Mg²⁺。实际进入你体内的镁含量（相对于被排出的部分）取决于多种因素，包括剂量、胃内容物以及你体内已有的镁含量。换句话说，剂量越高，吸收的镁就越少。

That’s all if the supplement dissolves in the first place. Magnesium oxide, which is usually the basis of the cheapest pills offered, doesn’t break down all that easily. In reality, magnesium oxide supplements mostly act as laxatives, drawing water into the intestines to flush out the excess salt.

这还是假设补充剂能够溶解的前提下。氧化镁通常是市面上最便宜药丸的基础成分，它并不容易分解。实际上，氧化镁补充剂大多起到泻药的作用，通过将水分吸入肠道来冲刷掉多余的盐分。

This is where the marketing comes in. There are other types of magnesium compounds that do dissolve better. Magnesium citrate, for example, has been shown to have the highest bioavailability in laboratory tests. Despite the fact that all these salts still break down in the intestine, some supplement labels also claim that their specific chemical blend targets the magnesium directly to certain parts of your body, like your muscles or your brain.

这就是营销发挥作用的地方。还有其他类型的镁化合物溶解性更好。例如，柠檬酸镁在实验室测试中被证明具有最高的生物利用度。尽管所有这些盐类最终都会在肠道中分解，但一些补充剂标签仍声称其特定的化学混合物能将镁直接输送到你身体的特定部位，如肌肉或大脑。

These claims are often based on experiments using rodents, and the animals are typically supplied with magnesium long-term at higher doses than found in a pill. One study in rats found that a salt called magnesium L-threonate increased the amount of magnesium in the brain and improved some manifestations of learning and memory. This is the basis of some of the more overzealous marketing in the supplement world, which proclaims that this special salt will take the magnesium right to your brain.

这些说法通常基于啮齿动物实验，而且这些动物通常被长期喂食比药丸中含量更高的镁。一项针对大鼠的研究发现，一种名为 L-苏糖酸镁的盐类增加了大脑中的镁含量，并改善了学习和记忆的某些表现。这就是补充剂界一些过度营销的基础，他们宣称这种特殊的盐能将镁直接带入你的大脑。

There are some human studies, but that’s not really what they say. A few small randomized trials reporting improvements in some cognitive tests or sleep have been conducted—but there are several important caveats. Some studies tested a mixture of substances, lasted for only a few weeks, or analyzed a very limited number of outcomes. Many of these studies can also not be considered independent, because they were funded by supplement manufacturers or led by their staff.

虽然有一些针对人类的研究，但它们的结果并非如此。目前已经进行了一些小型随机试验，报告称在某些认知测试或睡眠方面有所改善，但其中存在几个重要的注意事项。一些研究测试的是混合物质，持续时间仅几周，或者分析的结果非常有限。许多此类研究也不能被视为独立的，因为它们是由补充剂制造商资助或由其员工领导的。

Moreover, the studies—for extremely understandable reasons—didn’t measure magnesium content in the brain. So maybe a little more sneaks into your gray matter, but based on the scientific understanding of how these salts are processed, in all likelihood, a brain-focused magnesium supplement is still just an expensive laxative.

此外，出于非常可以理解的原因，这些研究并没有测量大脑中的镁含量。所以也许确实有一点点镁进入了你的灰质，但基于对这些盐类如何被处理的科学理解，很有可能，所谓的“健脑”镁补充剂仍然只是一种昂贵的泻药。

This story originally appeared on WIRED Czech Republic and Slovakia and has been translated from Czech.

本文最初发表于《连线》捷克和斯洛伐克版，并由捷克语翻译而来。