We get our first taste of glutamate from breast milk. This may explain why humans universally find the flavor of umami so tasty. We might eat less of it as we graduate to solid food, but glutamate in the form of MSG can help foods taste good no matter what age we are.
I recently became a mom. And I’m discovering that means there are a million new things for me to worry about. Everything from BPA to PFAs has got me thinking. But one thing I’m not worried about is MSG.
MSG is monosodium glutamate, the simplest form of umami flavor. Glutamate, the main component of MSG, is an amino acid that’s found in almost every plant and animal. Our bodies make it too – about 50 grams of it a day to be exact. And we store about 4.5 pounds of glutamate in our major organs like the brain, muscles, kidneys, and liver.
So, I guess it’s not surprising that glutamate is the most abundant amino acid in human milk. In fact, human milk contains six to nine times as much glutamate as cow milk does. We become familiar with the taste of glutamate and umami very early in life.
Infants Like Umami
With this much glutamate in breast milk, I guess it’s also not surprising that infants learn to like the umami flavor. Research has shown that babies smile after consuming something sweet (10% sucrose). They grimace after tasting sour (100% lemon juice). (By the way, this one can be unscientifically verified by any number of adorable YouTube videos.) They grimace and cry when given a bitter flavor (100% bitter melon juice). But they like umami. This is demonstrated by them expressing displeasure when eating vegetable soup, but enjoying vegetable soup with umami (soup + 0.1% MSG). From very early on, umami is a taste we like.
A newborn breast-fed infant consumes much more free glutamate for its size than adults do from food later in life. Even though our intake of it may decrease as we age out of infancy, glutamate remains safe and important to us across our lifespan.
Glutamate plays an important role in digestion by increasing salivation, signaling that a protein-rich meal is coming and fueling the cells of the GI tract. Glutamate (as MSG) can be used to season foods to make them taste better. And, MSG can be used to lower the amount of sodium in foods without affecting their taste, which is important to many of us long after we’ve had our first taste of glutamate.
Related reading: Is MSG Safe for Everyone?