Food Intolerance vs. Food Allergy

One link in particular from the Great Page of Food Allergy Informational Links that I posted yesterday stood out for me. Of all the thousands of questions I've received over a quarter century of talking about lactose intolerance, probably the most frequent and most confusing is the difference between a food intolerance and a food allergy. Let's start with this short article on the Palo Alto Medical Foundation site, Food Allergy vs. Food Intolerance.

A food allergy is actually an immune-system response. When someone eats certain foods (such as those listed above), the body mistakenly treats an ingredient in the food (usually a protein) as if it were a harmful pathogen. The body responds by creating a defense system (antibodies) to fight it. The allergic symptoms occur as a byproduct of the action of the antibodies that battle the invading food. Food intolerance is a broad term that describes any adverse reaction to food. ... Non-allergic food intolerance is often limited to an uncomfortable digestive-system response. The most common example of food intolerance is lactose intolerance, in which one's body is unable to break down the sugar (lactose) in dairy products. Other food intolerances can be caused by irritation to the digestive system by an ingredient in the food consumed.

That's the basics. Allergies and intolerances are different conditions, produced by the body reacting in different ways, often to a different set of triggers, with different symptoms and different severity. You wouldn't think that anybody would mix them up. And yet, life is never that simple and clearcut. The big issue for most of you reading this is dairy. Dairy is the trigger - the sole trigger - for lactose intolerance. Only the milk of mammals contains lactose: it's not found anywhere else in nature. Digestion breaks down milk into its smallest and simplest components and one of these is the compound sugar known as lactose. No digestive system of any mammal can digest lactose. It must be broken down into its own components, the simple sugars glucose and galactose, before it can be absorbed by the intestines. That's pretty weird if you think about. Why would a nursing mother go through the long series of extremely complex chemical reactions necessary to produce a unique compound sugar that can't be used in that form by the offspring? Nobody really knows. It's a scientific mystery. And a useful argument against the notion that humans or mammals or any living thing was "designed." Who would design a boondoggle like this? To break down, digest, a compound chemical the body manufactures enzymes, proteins that act as catalysts to speed up the process. The enzyme that digests lactose is called lactase. (Sugars end in "ose"; enzymes end in "ase". Remember that for your next crossword puzzle.) If the small intestine doesn't manufacture lactase, or creates too little of it, then some lactose will continue through the gut and wind up in the colon. Two things can happen during that journey, both bad. One is that lactose reverses what is called the molality of the system. Normally water enters the body from the intestines, nourishing you and leaving the end product, the stool, moist but intact. Lactose creates an environment in which water is pulled from the body into the intestines, setting up conditions that usually manifest as diarrhea. In addition, many of the dozens or hundreds of species of bacteria that live in your colon will jump on the lactose as a source of food, ferment it, and produce gas as part of the fermenting process. Heavy, smelly, long-lasting, awful gas - by itself or in addition to the diarrhea - is the consequence. Put together, those are the symptoms of lactose intolerance. Any other symptoms in an adult are extremely rare. Allergic reactions make more basic, underlying sense than lactose intolerance. You obviously want your body to fight off foreign invaders in your environment or in your food. But - here's where we question the whole "designer" thing again - the body often gets it totally wrong. Sometimes perfectly good, even healthy and helpful chemicals trigger reactions. In food, these reactions are always triggered by proteins, and never by sugar of any sort. You cannot be allergic to lactose. Only the proteins in milk, which are mostly in two families, the caseins and the wheys, can set off an allergic reaction. In theory that sounds like a great dividing point. In the laboratory it is. In life, there are few times when you have a dairy product that contains only proteins or only lactose. They almost always come mixed. How do you tell which is causing the problem? The best way is by the symptoms. Lactose intolerance always and only causes intestinal distress. A dairy allergy seldom does. Another link on that great links page lead to an informational page from the Journal of the American Medical Association.

SYMPTOMS Allergic reactions to food can be mild to severe. They usually occur within a few minutes of eating a food, though they rarely appear a few hours after ingestion. Symptoms can include runny nose, itchy skin, rash or hives, tingling in tongue or lips, tightness in throat, hoarse voice, wheezing, cough, nausea, vomiting, stomach pain, or diarrhea.

Those symptoms are in rough order of how common they are. Notice that stomach pain or diarrhea are last on the list. They do occur in certain people. Even so, the fact that the symptoms overlap coming from food in which the triggers overlap is a recipe for confusion. Doctors can usually sort this out just from listening to you describe your symptoms. And there are tests both for lactose intolerance and for food allergies that will definitely separate them. If you don't want to wait, the easiest first step is try lactase pills, available in any supermarket or pharmacy. Those work well on most people with lactose intolerance. If they don't, then the next step really is to see a doctor. A great many gastrointestinal illnesses produce the same symptoms and some, notably irritable bowel syndrome, can also be triggered by dairy. The cures for those are seldom as easy a box of inexpensive pills. Make sure you get the treatment you need.

Your Symptoms Aren't Always Coming from Lactose

One point made frequently in the NIH state-of-the-science conference on Lactose Intolerance (LI) was that people often misinterpreted the symptoms they got from food. Having symptoms, even when having dairy products, didn't necessarily mean that lactose was the cause.

Another larger and better test of this notion just appeared in the medical journal Clinical Gastroenterology and Hepatology. "Subjective Perception of Lactose Intolerance Does Not Always Indicate Lactose Malabsorption," by Francesc Casellas et al., Volume 8, Issue 7 , Pages 581-586, July 2010.

Abstract.

Background & Aims
Symptomatic lactose intolerance is common; however, abdominal symptoms that patients experience after ingestion of lactose-containing foods can have causes beyond lactose malabsorption. We aimed to determine whether symptoms that patients usually attribute to lactose intolerance are comparable to symptoms provoked by a controlled lactose challenge and whether these symptoms are related to lactose absorption capacity.

Methods
We performed an observational, prospective, transverse study of 353 patients referred for a lactose hydrogen breath test (HBT). Patients completed a validated questionnaire about symptoms associated with consumption of dairy products at home (home symptoms). After a 50-g lactose breath test, they completed the same questionnaire again (lactose challenge symptoms). Patients were assigned to groups of absorbers or malabsorbers according to HBT results and tolerants or intolerants according to the results of the questionnaire.

Results
The total symptom score was significantly higher for home symptoms than for the lactose challenge (16 vs 8, P < .01). Symptoms perceived at home were reported to be more intense than those that followed the lactose challenge for lactose absorbers compared with malabsorbers (16 vs 4, P < .01) and lactose tolerants compared with intolerants (12 vs 2, P < .05). Overperception of lactose intolerance at home was similar in men and women.

Conclusions
Daily life symptoms that patients associate with lactose intolerance are often unrelated to lactose malabsorption. Even among true lactose malabsorbers, symptom recall tends to be amplified by the patient. Thus, conventional anamnesis is a highly unreliable tool to establish symptomatic lactose malabsorption.

A 50 gram lactose challenge is enormous. That's the amount of lactose in four 8-ounce glasses of milk, more than almost anybody normally gets from food. So much lactose should create enormous and violent symptoms in anyone who is truly LI.

Yet the symptoms reported at home from normal food intake were more numerous and more severe than the symptoms reported from the lactose challenge. That's impossible to explain except subjectively. People either are getting their symptoms at home from foods other than lactose (or non-food reasons entirely) or else they simply report symptoms worse than they really are.

LI is real and people do get symptoms from it. But it's not the fault of the most or the worst symptoms for most people. Hard as that may be to believe, here's another test - and of a large number of patients - that replicates that claim.

Report from the LI Conference, part 19

This presentation and the next one are going to infuriate everyone. They're so connected that I'm going to vary from the way I've been handling these posts and put the two of them together.

Dosing, Symptoms, and Tolerable Doses of Lactose
Dennis A. Savaiano, Ph.D.
Professor and Dean
College of Consumer and Family Sciences
Department of Foods and Nutrition
Purdue University

Evidence-based Practice Center Presentation III: The Tolerable Amount of Lactose Intake in Subjects With Lactose Intolerance
Michael Levitt, M.D.
Professor
Minneapolis Veterans Affairs Medical Center
Division of Gastroenterology
Department of Medicine
University of Minnesota

The titles sound innocuous enough. If you click over and read the summaries of the presentations, you'll see that in broad generalities they say very little that I haven't said before and haven't repeated what feels like a dozen times just in my reports on the NIH Conference.

Believe me, the talks that they gave weren't so bland. I'll put it into a sentence.

Nobody gets symptoms from lactose.

Ridiculous, right? Ludicrous even. This whole blog is about lactose intolerance. My books are about LI. The conference was the state-of-the-science on LI. I've received thousand of letters and emails and posts from people telling me about their LI symptoms. Both presenters are researchers who've spent entire careers writing about LI.

Something's totally nuts here. I wish I knew what.

Figures 1 and 2 from Levitt's presentation won't reproduce well here so you have to click over and look at them. They represent the findings from a series of major studies on lactose. A minus sign means that a certain dose of lactose - with other foods in Figure 1, by itself in Figure 2 - produced "no or trivial symptoms" in the test subjects. "Severe symptoms" - the kind I think I get and the kind you tell me you get - are represented by a double plus sign. Remember that an eight-ounce glass of milk has about 12 grams of lactose in it.

When you look at the charts you'll see minus signs for all doses up to and including 12 grams. Virtually no one in the entire set of experiments got symptoms from the lactose in a glass of milk. If you used milk itself or some equivalent, a dose closer to what happens in the real world when you have dairy, no one, not a soul, got symptoms from two full glasses of milk.

Their breath hydrogen goes up, the certain signal that they are lactase maldigesters. But no symptoms.

Savaiano talked about experiments in which subjects received 50 grams of lactose over the course of a day without a single one of them having any symptoms.

Look, as I've reported earlier, the testing in the medical literature is bad. The groups are small, the experiments are not blinded, the doses are not physiologic, meaning that they don't correspond to the foods or eating experiences you get in everyday life. Still. Nothing? No symptoms? Sure, forcing a test subject to drink a full 50 grams of lactose in water - at one time the standard amount of lactose used in testing - will make people sick. But that's like testing for drunkenness by forcing a jug of moonshine down your craw in a single gulp. Anybody would be affected by that. It's so bad a test that doctors stopped recommending its use decades ago.

I didn't get it then, and I don't get it today. I'm reporting what the medical journal evidence says. In the next part I'll give the summary from the draft report. But I'll put the concluding paragraph here.

We stress the importance of additional scientific investigations to provide evidence-based and culturally sensitive recommendations about the amount of daily lactose intake that can be tolerated by lactose-intolerant individuals, with special emphasis on pediatric and adolescent populations and pregnant and lactating women.

That's the biggest "we don't understand what the hell's going on, give us some funding money" you'll ever see in scientific language.

Report from the LI Conference, part 6

The next presentation went to the heart of the whole conference. (Why wasn't it first?)

What Is Lactose Intolerance and How To Measure It
Richard J. Grand, M.D.
Professor of Pediatrics
Harvard Medical School
Program Director
Clinical and Translational Study Unit Director
Center for Inflammatory Bowel Disease
Children's Hospital Boston
[You might remember Children's Hospital Boston from my posts pointing to the research they've done to use injections to reduce milk allergy symptoms.]

What causes the different type, amount, intensity, and duration of lactose intolerance symptoms?

•Quantity of ingested milk
•Fat content of the milk
•Rate of stomach emptying
•Rapidity with which the milk is transported through the intestine
•Individual sensitivity to abdominal discomfort
•Capacity of bacteria in the colon to digest lactose not absorbed in the small intestine
•Psychological impact of anticipation of symptoms in those who have had previous symptoms during milk intake.

Quantity of ingested milk is obvious. The next three are related, and interrelated. As I said on Friday, it's critical to remember that most adults who are lactose malabsorbers still have some residual lactase activity. Anything that slows down the transit time of lactose gives the system more time for the lactose to interact with and be digested by that lactase. Whole bunches of factors regulate how fast food empties from the stomach and goes through the intestines, and one factor that is known to slow transit time is the fat content of the milk.

Items five, six, and seven are also related. The quantity of gases and bloating produced by the bacteria fermenting undigested lactose will depend on what types of bacteria you have and also on how sensitive you might be to intestinal rumblings. Knowing - or thinking that you know - that dairy causes problems might increase your discomfort. And there may be physical differences in your sensitivity to pain. We know for sure that people with Irritable Bowel Syndrome, for example, are far more sensitive to pain and pressure in the colon than people who don't have it. That may also be true for people with LI.

Dr. Grand also explained why an ordinary family physician might not want to send you for formal LI testing. The standard, simple Hydrogen Breath Test costs an average of $773. Somebody has to pay that.

Peppermint Extract for LI? No.

I'm doing mostly questions this week, some new, some old. I like the questions that make me think, and can't just answered by a yes or no, although a yes or no may emerge out of the available evidence. Like this one.

I read something about different things to try for lactose intolerance
including peppermint extract...Are there non-medicinal methods that work?

The basics. Lactose intolerance (LI) is caused by the body not producing enough lactase to digest all the lactose that comes in. That lactose goes to the colon, where it is fermented by bacteria that live in the colon.

That suggests two approaches to alleviating the symptoms: add lactase or get rid of the bacteria.

And those are the two approaches taken. Lactase pills provide the missing lactase. Probiotics, from the cultures in yogurt to targeted pills like Digestive Advantage Lactose Intolerance, DairyCare, or Lactagen, provide the different type of bacteria that digest lactose rather than ferment it.

Neither approach affects the body itself. Lactase is a natural enzyme that works only on lactose. The bacterial supplements thrive in the colon and eat the lactose, but don't themselves enter the body. I'd be hard-pressed to call either one of them medicines. In fact, I'd say that both approaches are non-medicinal to start with.

Being non-medicinal is a big advantage. Neither lactase nor probiotics have side effects. (A tiny, tiny handful of people are allergic to the fungus that lactase is grown from, but even that is not a reaction to the lactase itself.)

Back to peppermint extract. It doesn't do either of the things known to reduce LI symptoms. What does it do? Traditionally, peppermint extract has been used to relieve bloating and gas. LI produces both bloating and gas, because the fermentation of the lactose. There would seem to be a connection.

If so, it's hard to find medical research that backs it up. One interesting report is "Peppermint oil (Mintoil®) in the treatment of irritable bowel syndrome: A prospective double blind placebo-controlled randomized trial," by G. Cappelloa, et al. in the journal Digestive and Liver Disease, Volume 39, Issue 6, June 2007, Pages 530-536. It found that peppermint extract relieved symptoms of Irritable Bowel Syndrome better than a placebo. But patients with LI were excluded from the testing. I can't find any articles that report on testing peppermint extract on patients with LI.

Right now I'd have to say that peppermint extract may help soothe the insides of certain people. Does it help LI? No evidence that it does. Is it non-medicinal? No more than the choices that are known to work. Would I recommend it? No. But reaching that answer proved more complicated than I thought at first.

How Long Does a Lactose Attack Last?

I hate getting questions that I can't answer, but "it depends" is all-too-often the only real comment that I can make.

This was in an email I recently received:

After reading pretty much everything on your website and a lot of others, I still haven't found the answer to this question: How long after you stop consuming lactose does it clear your system and stop causing symptoms? Are there any residual effects and/or damage to the gut?

There is very little that's more individual than a lactose attack. It varies not just by person to person, but every single time you take in more lactose than you can digest. How much lactose you eat, whether it's part of a meal or whether it's mostly liquid, how much lactase may remain in your system, and how sensitive your intestines are all play a major role.

The symptoms may be mild or severe and may last for a short time or for quite a while.

You cannot damage the gut by having lactose. If you are particularly sensitive or also have Irritable Bowel Syndrome, your intestines may keep on spasming even after the lactose is gone. At that point taking an antidiarrheal drug to stop the spasming is a good idea. Don't take one right away thinking that you're stopping the symptoms. You'd just be keeping the lactose in you longer.

Extreme cases of lactose intolerance (LI), meaning times when someone keeps having milk despite the symptoms, can lead to dehydration from the water loss. That used to happen in the days before people knew what LI was. (If you didn't know that milk caused your problem you wouldn't think to stop having it.) I haven't heard of a case of dehydration in a very long time. Knowing all about LI is far too common in the U.S. This might be a concern in some other countries where understanding of LI is just beginning to reach our levels.

LI is uncomfortable but not dangerous. The sympotms will go away when the lactose is gone (and you make sure not take in more lactose). It just seems like forever.

Constipation - The Other Intestinal Ailment

I seldom talk about constipation here. Diarrhea is one of the major symptoms of lactose intolerance, after all, and even some with dairy allergies or hypersensitivities may suffer from it. Some babies with a cow's milk protein allergy may indeed have constipation as a symptom, but it's rare in adults.

That doesn't mean that constipation can be ignored. Just as I warn that diarrhea may have hundreds of causes, so can constipation. And some of those are relevant to the way many of us live our lives.

An article by Kay Ledbetter for AgNews, a publication of the Texas A&M University System Agriculture Program, notes that older adults especially may be victims of constipation, with some extremely serious complications.

Constipation can account for some of the cases of delirium in older adults, causing symptoms similar to those of Alzheimer's disease, said Andrew B. Crocker, [Texas Cooperative] Extension gerontology specialist.

Nearly everyone becomes constipated at one time or another, Crocker said. But older adults may have more bouts due to lack of exercise, diets low in fiber, not drinking enough liquids and taking more prescription medications.

Most of the time it is not serious, he said. However, sometimes it can cause agitation, aggression and combativeness in older adults.

Crocker also mentioned that a variety of medication may have constipation as a side effect.

Some medicines may lead to constipation. These include some drugs used to treat depression, antacids containing aluminum or calcium, some allergy medicines, some high blood pressure drugs and some drugs used to treat Parkinson's disease.

Many people who do not drink milk do use antacids as a cheap and effective way of supplementing their calcium intake. It's not clear from the article which allergy medications are a problem, but you can check any you take with your doctor of pharmacist.

The route around constipation? Fiber and fluids.

Add fiber to the diet by eating more fresh fruits, vegetables and more whole-grain cereals and breads. Dried fruit such as apricots, prunes and figs are high in fiber. Add small amounts of unprocessed bran to baked goods, cereals and fruit. This may cause bloating and gas for a few weeks. Make diet changes slowly to allow the system to adapt.

Be sure to get enough fluids. Drinking lots of water and juices helps some people get back to regular bowel movements.

Stay active. This is important for overall health too.

Milk Allergy Advice from the Mayo Clinic

A few months ago, I posted information about Preventing food allergy in children from an article on the Mayo Clinic website.

Today's article is just as useful. It's called simply Milk allergy.

Here's just a very brief excerpt:

Signs and symptoms
Signs and symptoms of milk allergy differ from person to person and occur within a few minutes to a few hours after ingesting milk. In some cases, reactions to a milk allergy develop after exposure to milk for an extended period of time. Rarely, infants have an allergic reaction to small amounts of cow's milk protein passed through their mother's breast milk.

Signs of a milk allergy that may occur immediately after consuming milk include:

Wheezing
Vomiting
Hives
Signs and symptoms that may take more time to develop include:

Loose stools (which may contain blood or mucus)
Diarrhea
Abdominal cramps
Coughing or wheezing
Runny nose
Skin rash

Milk allergy or milk intolerance?
It's important to differentiate a true milk allergy from milk protein intolerance or lactose intolerance. Unlike a milk allergy, intolerance doesn't involve the immune system. Milk intolerance causes different symptoms and requires different treatment than does a true milk allergy. Common signs and symptoms of milk protein or lactose intolerance include digestive problems, such as bloating, gas or diarrhea, after consuming milk.

There are many pages more information, including more anaphylaxis Signs and Symptoms, and:

▪ Causes
▪ Risk factors
▪ When to seek medical advice
▪ Screening and diagnosis
▪ Complications
▪ Treatment
▪ Prevention

By all means, check this out.

One to Three Pints of Gas a Day - And Not in Your Car

Everybody knows that one of the symptoms of lactose intolerance is gas. Lots of gas. Foul, smelly gas. Noisome gas, for those who know the proper meaning of the term.

The gas is produced when undigested lactose is fermented in the intestines by the bacteria that naturally live there.

An article from ConsumersReports.org by their chief medical adviser Dr. Martin M. Lipman tells us more:

The average person produces one to three pints of gas per day and eliminates it in 14 to 23 passes, some while asleep. More than 99 percent of this gas mixture is odorless, and consists of carbon dioxide, nitrogen, and oxygen, which we inadvertently swallow when we eat, drink carbonated beverages, chew gum, or smoke. Some carbon dioxide is made in the stomach.

In addition, the normal bacterial population of our colon (large bowel) produces a tiny amount of hydrogen gas and methane by fermenting the carbohydrates left over from the small intestinal digestive process and forming hydrogen sulfide (like the smell of rotten eggs), methanethiol (like the smell of decomposing vegetables), and dimethyl sulfide (a heavy sweetish odor). In fact, less than 1 percent of the gas we produce accounts for all of the odor.

Passing that gas mixture causes the anal sphincter to vibrate, producing a veritable symphony of sounds depending on the force with which the gas is expelled and the resistance of the sphincter. Who can forget that rousing campfire scene from Mel Brooks' 1974 masterpiece, "Blazing Saddles"?

When excess gas occurs alongside nausea, vomiting, diarrhea, constipation, or involuntary weight loss, the need to see a physician is obvious. But by and large, gas as an isolated complaint is rarely due to a serious disorder. When a patient comes to me complaining about excess gas, a careful history, a physical exam, and a few well-chosen laboratory tests can rule out those few, more notable, causes: irritable bowel syndrome, lactose intolerance, celiac disease, or gastroesophageal reflux disorder. In the vast majority of cases, flatulence indicates nothing more than that the patient is alive and eating a healthy diet.

Unfortunately, there's nothing you can do to eliminate gas once it's already begun. Far better to remember to take lactase pills at the first bite of dairy and not feel sorry later.

Similac Sensitive R.S. Lactose-Free Formula

Abbott's Laboratories has just announced an expanded, improved line of Similac® infant formulas. The latest additions to the Similac family include Similac Sensitive™ and Similac Sensitive R.S.™ – both designed to address common feeding problems such as fussiness and gas – and Similac® Go & Grow™, designed to help older babies get the nutrition they need as solid foods are introduced into their diets.

Their press release says:

Similac Sensitive is made with a unique blend of carbohydrates that helps reduce fussiness and gas due to lactose sensitivity. Research shows almost half of all babies with feeding issues are switched to a tolerance formula, like Similac Sensitive, by three months of age.¹ Similac Sensitive provides moms a new alternative to address these feeding challenges.




Similac Sensitive R.S., made with added rice starch, is a new formula specifically designed to help reduce the frequency of common spit-ups. According to the American College of Gastroenterology, almost all infants reflux or regurgitate a portion of their feeding at one time or another.² Similac Sensitive R.S. has been clinically shown to reduce the frequency of spit-up by 54 percent.³

1 ACNielsen HH Panel 2000-2003, Ziment 2002-2003.
2 Marsha Kay, MD, “Common Gastrointestinal Problems in Pediatric Patients.” The American College of Gastroenterology, http://www.gi.org/patients/gihealth/pediatric.asp.
3 Among healthy 2-month-old infants, compared to standard formula. Clinical Study AJ68, February 2001, Ross Products Division, Abbott Laboratories, Columbus, Ohio.

One other possibility for those with dairy allergy concerns is Go & Grow.

Another new formula from Abbott, Similac Go & Grow, is specially designed for the needs of growing babies, ages 9 to 24 months. Similac Go & Grow offers balanced nutrition for older babies as solid foods and milk are introduced into their diets. Similac Go & Grow provides at least 25 vitamins and minerals and more than 30 percent of the Daily Value of calcium, iron and vitamin C in just one 8-fluid-ounce sippy cup. Similac Go & Grow is available in both milk- and soy-based formulas, and will replace Similac® Advance® 2 and Isomil® Advance® 2 as the Similac solution for improved toddler nutrition.

Suggested retail price for Similac Sensitive is $13.79 for 12.9-ounce Powder, $24.99 for 25.7-ounce Powder, $4.49 for 13-fluid-ounce Concentrate and $5.99 for 32-fluid-ounce Ready To Feed (RTF). For Similac Sensitive R.S. the suggested retail price is $5.99 for 32-fluid-ounce RTF. Similac Go and Grow's suggested retail price is $10.99 for 12.9-ounce Powder and $19.99 for 24-ounce Powder.

The information about Sensitive or Sensitive R.S. isn't up yet at the website. However, this page about Similac® Lactose Free Advance at the Ross Labs site may be of help, and you can search for the other Similac products from there.