Lactose Intolerance in Infants

You're a mammal. I'm a mammal. We're all mammals. And that means we all are programmed genetically to drink mother's milk until we are weaned.

So lactose intolerance and infants should be two terms never used together. Yet a pediatric gastroenterologist I once interviewed told me that 10-15% of his patients were lactose intolerance.

To explain this, two facts are needed. One is that the intestines of an infant are delicate and a whole variety of problems can interfere with the lactase-making ability. The other is that a pediatric gastroenterologist is going to see a non-representative sampling of a) all infants and b) sick infants. Even so, maybe one percent of all babies suffer from temporary lactose intolerance at any given moment. The usual term for LI that is caused by an outside source rather than natural shutdown is Secondary LI, but Temporary LI is often used for babies as a reminder to the suffering parents that the condition will probably go away as soon as the child's intestines heal.

At The MedGuru site, Dr. Sania Siddiqui has a decent summary of what to look for and do. It's very basic but a good place to start for information.

Report from the LI Conference, part 5

I'm sure some professional jargonistas will come in here and challenge me, but for sheer brain-bending technical mumbo-jumbo in the medical field nothing is more opaquely baffling than the titles of papers on genetics. What would you do with a paper titled "The homeodomain protein Cdx2 regulates lactase gene promoter activity during enterocyte differentiation"?

Whatever that means, it was co-authored by the third presenter of the morning.

Cellular and Molecular Biology of Lactase
Eric Sibley, M.D., Ph.D.
Associate Professor
Division of Pediatrics-Gastroenterology
Stanford University School of Medicine

There are three types of lactose intolerance. If the lactase enzyme never develops at all, then newborns can't have any lactose. They literally starve to death unless a lactose-free formula is given to them almost immediately. This is how LI was first discovered as a medical condition, in fact. Because it exists from birth, this type is called Congenital LI.

Primary LI is the type that most of us have, the natural condition of all mammal. Lactase production declines after weaning, but we can drink milk until that time without symptoms.

A whole medical textbook of conditions - drugs, diseases, surgeries, anything that damages or shocks the intestines - can known out the lactase-making mechanism no matter what your age or status is otherwise. This type is known as Secondary LI.

Why is lactase so vulnerable to being knocked out? Sibley said:

Lactase is a brush border membrane protein produced by enterocytes, the absorptive epithelial cells of the small intestine. The human lactase protein is initially synthesized as a 210–220 kDa immature peptide. The precursor peptide is then processed by glycosylation and cleavage, and finally inserted into the brush border membrane as a mature 160 kDa subunit homodimer.

Lactase is made in the small intestine. Take a biopsy of a section of the inside of the small intestine and a whole invisible world is revealed under a microscope. The insides are covered in tiny projectiles. Imagine a piece of rolled-up shag carpeting and you have the idea. Each projection is called a villus and the outside of the villus, the part that interacts with the broken-down pieces of carbohydrates, proteins, and fats, the part that actually does the digestion, is a membrane called the brush border.

Lactase is made in the brush border, but not in all of it. Lactase is made only at the very tip of the villus. Scientists find that the other enzymes that digest sugars appear the farther you go down the side of the villus, toward the valley (known as the crypt). That's a more protected region than the top. So if anything is going to harm the inside of the intestine, lactase production will go first.

[Why? My guess is that throughout 99% of mammalian history, lactose wasn't very important as a nutrient except for that short time before weaning. Most animals, humans included, live the vast majority of their lifespan after weaning. So if anything has to be first or be most vulnerable, lactase production was the least valuable and bodies could chance that letting it go but protecting the others would lead to higher survival in the long run.]

Here's another fact with huge implications.

Postdecline, the level of lactase activity is 5–10% of childhood levels in most populations worldwide.

That's why most people can have some lactose, some dairy products, even if they are lactose malabsorbers (or lactose non-persisters or are LI in the common use of the term). Your lactase activity doesn't go to zero. It goes down a lot, but not to zero. That helps explain why any activity that helps to slow down the rate at which lactose travels through the intestines (having milk with a meal or having milks with more solids [like whole milk or chocolate milk]) will give your remaining lactose more time to work and reduce overall symptoms.

Secondary Lactose Intolerance

Lactose intolerance is a genetic problem. You are born with a gene that tells your body whether or not it will eventually shut off the lactase-making mechanism after the age of weaning.

You hear that everywhere. I say it myself fairly often. And it's true.

Up to a point.

You can be lactose intolerant and have the gene that never shuts lactase down. Both. That's because the lactase-making mechanism is delicate and can be damaged by any number of things. Diseases, drugs, surgery.

And the effect can be permanent.

Andrea McLean, a British television personality (she's one of the Loose Women), wrote about her experiences with secondary lactose intolerance for the Daily Mail.

It started, innocently enough, with a severe bout of food poisoning 20 years ago. I was in my 20s, backpacking around India.

The culprit was a bottle of water - I noticed the lid came off a bit too easily but I drank it anyway. Later I walked past the stall I had bought it from and saw a man filling identical bottles from a tap.

Within 24 hours I was hideously ill. I spent the next few weeks groaning and clutching my stomach on a mattress in a darkened hostel dorm room, before finally the symptoms began to subside.

And a year later, when I got back home, things still weren't quite right. A couple of times a week, I had to rush to the loo. I felt tired and lethargic.

My GP referred me to the Hospital for Tropical Diseases in London, where I spent what seemed like the next year having blood test after urine test. Was something hideous lurking inside me?

It was nothing so exciting. The tests all came back negative. Instead, I was told to try cutting certain foods from my diet, starting with dairy.

Within a week I felt back to my old self. I had developed secondary lactose intolerance.

Secondary lactose intolerance is treated exactly the same way as the kind that is genetic, known as primary lactose intolerance. Take lactase pills or avoid dairy.

Goats Get Lactose Intolerance

Remember the old joke in which a teacher gives a class assignment to write about a pet peeve and some future delinquent writes about his pet, Peeve?

It's not very funny. I know.

Not funny. Just relevant. To me, at least. You can't imagine how many times I go on the Internet and find people dumb or oblivious or self-interested enough to proclaim that goat's milk is acceptable for people with lactose intolerance.

Here are some examples I pulled off of Google News, just this month.

FoodBizIntel: Meyenberg Goat Milk Products

Goat milk has a delicious, gourmet taste, is easily digested, and is a real milk alternative to lactose sensitivity.

Tabbouleh Chavrie Salad

Healthy tips about our all-natural cheese include goat cheese contains 30% less fat than sour cream and many cow’s milk cheese. It is gluten-free and is easily digestible for those who are lactose intolerant.

Editors' Picks: Automaker offers goat with purchase

Goat's milk, he added, "provides a nutritious alternative for the growing number of lactose-intolerant people ...

Milk, it was good for you as a kid, it is good for you as an adult

There is goat’s milk which has slightly different properties than cow’s milk. Those who are lactose intolerant may be able to drink goat’s milk.

Not just kidding around

Goat's milk contains a different protein base than cow's milk and so can often be tolerated by people who are lactose intolerant or have other digestive sensitivities, Heather said.

That would be no, no, no, no, and no.

Goat's milk has almost exactly as much lactose as cow's milk. Some people who are allergic to cow's milk can drink goat's milk because it contains a different set of proteins. But that is almost exactly opposite to what these nitwits claim.

How do I know that goat's milk will affect the lactose intolerant?

How about a lactose intolerant goat?

J Am Vet Med Assoc. 2000 Aug 1;217(3):372-5, 340.
Secondary lactose intolerance in a neonatal goat.

Weese JS, Kenney DG, O'Connor A.

Department of Clinical Studies, Veterinary Teaching Hospital, Ontario Veterinary College, University of Guelph, Canada.

A 2-week-old Toggenburg kid was evaluated for persistent diarrhea and poor body condition. The herd had high morbidity and mortality associated with diarrhea in neonatal kids. Lactose intolerance was diagnosed on the basis of results of a lactose tolerance test and glucose absorption test. Clinically normal herdmates were used as control animals. The kid responded to lactase supplementation. Cryptosporidium organisms were detected in feces of several affected kids during episodes of acute diarrhea. Lactose intolerance was presumed to have developed secondary to intestinal cryptosporidiosis.

In other words, this poor baby goat got an intestinal ailment, and developed secondary lactose intolerance, in exactly the same way that so many humans, especially infants and babies. do when their intestines are attacked by something like the "stomach flu," actually a gastrointestinal ailment. The cure was also exactly like that of a human: use lactase to digest the lactose and reduce the symptoms.

Everybody. Please stop saying that goat's milk is for people with lactose intolerance. That's not true. Even the goats know better.

Secondary Lactose Intolerance

Most people in the world have what is known as primary lactose intolerance. That means they are genetically destined to lose the ability to manufacture the lactase enzyme that digests lactose as they grow older.

That's not the only route to LI, though. Anybody of any genetic heritage can lose the ability to manufacture lactase if surgery, disease, drugs, or other catastrophic events disrupt the intestines.

Here's an example taken from an article written by Ellen Rowland in the Hagerstown MD Herald-Mail.

Since my bariatric surgery Feb. 20, I have lost 50 pounds. I am very happy with that. Most people tell me that they can see a difference. ...

Do I have any regrets having this surgery done? No. I am pleased with the way things have turned out. If you were to ask me early in April, my answer might have been different because I was getting nauseated and didn't know why. Now, I feel great. ...

I am eating solid foods, and for the most part, I digest them well, as long as I chew thoroughly and eat slowly. I know when my stomach is full and I just push the plate away, because if I were to continue eating I'd just throw up. It's not worth it. ...

I also discovered that I am now lactose intolerant. I became sick to my stomach after I would drink my protein shake and sometimes whatever I ate. But I do not drink milk much anyway, so that is not a great loss.

It's Flu Season. Stomach Flu Season.

I hope you all understand that the term "stomach flu" is a horrible misnomer. Both parts are equally wrong. It's not the flu and your stomach has little to do with it.

The disease is properly called gastroenteritis. The influenza virus does not cause it, although a whole host of other virus types can.

So why "stomach flu"? Vomiting is often a symptom, along with diarrhea, so the name is catchy and seemingly descriptive.

The affected person may also have headache, fever, and abdominal cramps ("stomach ache"). In general, the symptoms begin 1 to 2 days following infection with a virus that causes gastroenteritis and may last for 1 to 10 days, depending on which virus causes the illness; however, most episodes last from 1-3 days.

Anything that affects the intestines is a concern for those of us with lactose intolerance, and for many who aren't. Remember that few people manufacture no lactase at all. Most of us just don't make enough at the best of times, although most of us normally can have some dairy products without symptoms. Reduce lactase production and trouble can follow. Same is true for those who ordinary have no problems at all with dairy. A temporary (also called secondary) lactose intolerance can result.

That's what brought to my attention this Daily News article by Rosemary Black. She noted that "stomach flu" cases appear to be increasing this year and devoted an article to what to do and not do. She included this pertinent point:

The myth: Cheese is binding and a good food to eat after the stomach flu.

The reality: You may want to avoid cheese and ice cream. "Whenever you have an intestinal inflammation, the enzymes that break down the lactose aren't functioning all that well," [Dr. Christina Tennyson, assistant professor of clinical medicine at Columbia University Medical Center] explains. "So stay away from dairy products for a couple of days."