Until I hit puberty, I was allergic to milk. When I explained why I had turned down both the pizza and the ice cream cake at a birthday party, people would nod knowingly and say, "Oh, lactose intolerance." I admit I got a little tired of having to clarify, "No, milk allergy. I get hives, not just an upset stomach."
It's an understandable mistake. Unfortunately, a whole bunch of people who should know better, including pediatricians, still have trouble telling the difference. As a result, otherwise healthy infants are regularly being diagnosed with "lactose intolerance" — which is basically a scientific impossibility.
To navigate the spectrum of reactions to dairy, you first need to know something about what's in nature's baby food. Breast milk has several components: vitamins and minerals (most famously calcium); fat, known to you and me as butter; proteins (casein and whey are the prominent ones in cow's milk); and milk sugar, known as lactose.
Proteins and lactose are usually the two troublemakers, but for very different reasons.
What we usually think of as lactose intolerance appears only in older kids and adults.
Click to view chart.
A crucial distinction between them is that proteins differ between different mammals' milk, but lactose is lactose is lactose. Lactose only varies in quantity: the proportion of lactose in milk increases with the size of a species's forebrain, notes Linda Folden Palmer in her book Baby Matters, so human milk actually has more lactose than any other kind. (In other words, breastmilk is sweeeet!)
This means a condition in which a baby couldn't digest lactose would have been fatal up until very recently.
A couple of such recessive genetic conditions do exist, but they are very rare and are identified within weeks, if not days, of birth, because babies who have them will fail to gain weight or thrive until put on a lactose-free diet. This is known as "congenital" lactose intolerance.
What we usually think of as lactose intolerance appears only in older kids and adults. Mammals usually start to lose the ability to produce lactase, the enzyme that digests lactose, around the time they wean. (This is why you can give milk to kittens but not to adult cats.) Without lactase, if you drink straight-up milk or other dairy that still has lactose in it (butter and most cheeses don't), you get uncomfortable bloating, cramps, nausea, or diarrhea from the undigested sugar in your gut.
Some pockets of humans (Caucasians mostly) who relied on domestic livestock developed the unusual ability to keep producing lactase into adulthood. In an ethnocentric moment, these milk-drinkers assumed this ability was the norm and named the other 75 percent of the world's population "lactose intolerant." This kind of lactose intolerance usually doesn't show up until age four or five, often much later.
If you do the math, you will notice that neither of these conditions would apply to healthy infants. And yet, infants who are colicky, have reflux, or show other signs of gastrointestinal distress are being diagnosed as lactose intolerant all the time, sometimes officially by doctors, sometimes informally by concerned parents.
©2008 Miriam Axel-Lute and Nerve Media
About the Author
|
|
Related Articles
|
|
Miriam Axel-Lute is a freelance writer, editor and poet. She is an
award-winning columnist for Metroland, and lives in Albany with her two partners and daughter. Her website is mjoy.org. |
|
|
-
by Jean Railla
Why today's women are choosing to have babies alone.
-
by Miriam Axel-Lute
Official advice about lead poisoning is either too scary or not scary enough.
-
by Kathi Alexander
Is "child-centered" parenting producing a generation of brats?
|
