What is MSG, and is it actually bad for you? - Sarah E. Tracy

翻译人员: Xiaowen Wang 校对人员: Helen Chang

In 1968, Dr. Robert Ho Man Kwok felt ill after dinner at a Chinese restaurant.

1968 年，

郭浩民医生在中国餐厅 吃过晚餐之后感到不适。

He wrote a letter detailing his symptoms to a prestigious medical journal,

他写信给一份很有名望的 医学期刊详述他的症状，

pondering whether his illness had resulted from eating monosodium glutamate—

怀疑他的不适是不是因为 吃了麸胺酸钠，

also known as MSG.

又名味精。

Kwok’s connection between his headache and this common seasoning

郭医生把他的头痛和这种 美式中餐中常见的调味料联系起来

in American Chinese cuisine was just a hunch.

只是一种直觉。

But his letter would dramatically change the world's relationship with MSG,

但他写的这封信却极大程度上 改变了全世界对味精的看法，

inspiring international panic, biased science,

引发了国际恐慌 和有失偏颇的科学研究

and sensationalist journalism for the next 40 years.

以及耸人听闻的新闻报道， 长达40年之久。

So what is this mysterious seasoning?

这种神奇的调味料究竟是什么？

Where does it come from, and is it actually bad for you?

它从哪儿来，对人体 又是否真的有害呢？

MSG is a mixture of two common substances.

味精是由两种简单分子构成的混合物。

一种是纳，它被公认为 我们饮食中不可或缺的一部分，

Sodium, which is well-established as an essential part of our diet,

and glutamate, a very common amino acid

另一种则是谷氨酸， 一种非常常见的氨基酸

found in numerous plant and animal proteins.

存在于多种动植物蛋白质中。

谷氨酸对人体消化和肌肉功能

Glutamate plays a key role in our digestion, muscle function,

以及免疫系统都至关重要

and immune system.

Around the time of Dr. Kwok's letter,

在郭医生发表信件的时代，

谷氨酸被认为是 大脑化学的重要组成部分。

it had been identified as an important part of our brain chemistry.

Our body produces enough glutamate for all these processes,

谷氨酸作为机能必需， 除了会被人体产生以外，

but the molecule is also present in our diet.

还存在于我们的日常饮食中。

你可以在食物中尝出 它标志性的可口味道，

You can taste its signature savory flavor in foods

比如蘑菇，芝士，西红柿和肉汤里。

like mushrooms, cheese, tomatoes, and broth.

正是为了追求这种浓郁的口感， 在1908年人们发明了味精。

Chasing this rich flavor is what led to MSG’s invention in 1908.

一位名为池田菊苗的日本化学家

A Japanese chemist named Dr. Ikeda Kikunae

was trying to isolate the molecule responsible for a unique flavor

尝试分离这种具有独特风味的分子，

他称之为“umami”， 意为“一种美妙的鲜味”

he called “umami,” meaning “a pleasant, savory taste.”

Today, umami is recognized as one of the five basic tastes in food science.

现在，鲜味已被认定为 食品科学五大基本味觉之一。

每一种基本味觉都是 由独一无二的分子机制产生的

Each basic taste is produced by unique molecular mechanisms

that can’t be replicated by combining other known tastes.

无法通过结合其他已知味觉来复制。

对于鲜味来说

In the case of umami,

those mechanisms arise when we cook or ferment certain foods,

这些分子机制产生于 我们烹饪或发酵某些食物时

食物中的蛋白质被破坏， 从而产生了谷氨酸等氨基酸。

breaking down their proteins and releasing amino acids like glutamate.

但是池田找到了一条 诱发这种化学反应的捷径。

But Ikeda found a savory shortcut to producing this chemical reaction.

By isolating high quantities of glutamate from a bowl of noodle broth

通过从一碗面汤中分离出大量谷氨酸

并将其和另一种 风味增强剂结合，例如纳，

and combining them with another flavor enhancer like sodium,

池田发明了一种调味品， 能瞬间从任何一盘菜里调出鲜味来。

he created a seasoning that instantly increased the umami of any dish.

这一发明取得了重大成功。

The result was a major success.

By the 1930s, MSG was a kitchen staple across most of Asia;

到20世纪30年代，味精成为了 亚洲大部分地区的厨房必备品；

and by the mid-20th century,

而到了20世纪中期，

it could be found in commercial food production worldwide.

在全世界的商业食品生产中 都能找到味精。

所以当时郭医生的信立刻引燃了众怒。

So when Dr. Kwok's letter was published, the outrage was immediate.

Researchers and citizens demanded a scientific enquiry

研究学者和普通百姓 都要求进行一次科学调查

矛头直指这种流行的添加剂。

into the popular additive.

一方面，这种诉求并不无理。

On one hand, this wasn’t unreasonable.

此前味精并未经过毒性测试，

The substance hadn't been tested for toxicity,

而它对于健康的影响也基本未知，

and its health impacts were largely unknown.

However, it’s likely many people weren’t responding

然而，大部分人可能并非是在针对

to a lack of food safety regulation,

食品安全监管的匮乏，

而是那封信的标题：“中餐馆综合征”。

but rather the letter’s title: “Chinese Restaurant Syndrome.”

尽管味精在许多菜系中普遍使用，

While MSG was commonly used in numerous cuisines,

许多美国人长期以来 对亚洲的饮食习惯持有偏见，

many Americans had longstanding prejudices against Asian eating customs,

认为它们是外来的，是危险的。

labeling them as exotic or dangerous.

这些污名助长了 带有种族偏见的新闻报道，

These stigmas fueled racially biased journalism,

并营造了一种在中餐馆就餐 会使人生病的恐惧。

and spread fear that eating at Chinese restaurants could make you sick.

这种怀有成见的报道延伸到 许多关于味精和鲜味的研究，

This prejudiced reporting extended to numerous studies about MSG and umami,

这些研究的结果远没有 新闻头条所说的那么有说服力。

the results of which were much less conclusive than the headlines suggested.

For example, when a 1969 study found that injecting mice with MSG

例如，一项1969年的研究显示 将味精注入小鼠体内

会对它们的视网膜和大脑 构成严重伤害，

caused severe damage to their retina and brain,

一些新闻媒体便贸然断定 食用味精会造成脑损伤。

some news outlets jumped to proclaim that eating MSG could cause brain damage.

Similarly, while some studies reported that excess glutamate

同样，虽然一些研究发现过量的谷氨酸

could lead to problems like Alzheimer’s,

可能会引发阿兹海默症等疾病，

these conditions were later found to be caused by internal glutamate imbalances,

但后来发现这些症状是由 体内谷氨酸盐不平衡所导致的，

与我们食用的味精没有关系。

unrelated to the MSG we eat.

These headlines weren't just a product of prejudiced reporters.

这些新闻头条不仅只是 有偏见的记者们的作品。

Throughout the late 60s and early 70s,

从60年代末一直到70年代初，

many doctors also considered “Chinese Restaurant Syndrome”

许多医生也认为“中餐馆综合征”

to be a legitimate ailment.

确实是一种疾病。

Fortunately, today’s MSG researchers no longer see the additive

幸运的是，现在的味精研究学者们 不再用有色眼镜

看待这种添加剂。

in this discriminatory way.

最新研究明确了谷氨酸 在人体新陈代谢中所起的关键作用，

Recent studies have established the vital role glutamate plays in our metabolism,

一些学者甚至认为味精 是一种更健康的选择

and some researchers even think MSG is a healthier alternative

而不是添加脂肪和纳。

to added fat and sodium.

Others are investigating whether regular consumption of MSG

另一些学者在研究适量食用味精

could be linked to obesity,

是否会导致肥胖，

and it is possible that binging MSG produces headaches,

对一些人而言， 大量食用味精可能会造成头痛

chest pains, or heart palpitations for some people.

胸痛、心悸等症状。

但对大部分食客来说， 适量使用这种调味品

But for most diners, a moderate amount of this savory seasoning

seems like a safe way to make life a little tastier.

似乎是一种能使生活 更有滋有味的安全方式。