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.

Study Confirms That Raw Milk Doesn't Work for Lactose Intolerance

News flash! Ball dropped from hand hits ground! News flash! Sun rises in east! News flash! Raw milk is no different from pasteurized milk!

Nobody in the world should be surprised by any of these. Even so, there somehow exists a large community of people who think that for some reason - usually a scientifically illiterate one - people with lactose intolerance who can't drink pasteurized milk can drink raw milk.

A lot of these people get paid by the Weston A. Price Foundation to put out propaganda touting the wondrous properties of raw milk. They even released a "study" in 2008 in which they surveyed a group of raw milk advocates and guess what they found? Amazingly, the people who buy and drink raw milk say that they can drink raw milk. The "study" was never published in a peer-reviewed journal so it wasn't checked by actual scientists. The FDA took one look at the methodology of the study and metaphorically walked out of the room.

I talk about that study and a magazine article by raw milk propagandist David Gumpert in Raw Milk Article Long but Flawed.

Gumpert is back with another article, this one for Grist Magazine.

The folks at the Weston A. Price Foundation, apparently having found out that no one who is not already a True Believer will swallow a fake "study" having as much scientific validity as one of those online "test your own IQ" sites. They hired Christopher Gardner, an associate professor of medicine at Stanford Medical School to do a real, controlled study.

Here's the result you get when you conduct a real study.

"The data fail to support our hypothesis that Raw Milk confers some benefit over Pasteurized Milk in the form of an improvement in the experience of symptoms of lactose intolerant adults."

Man, I would have loved, loved, loved to have seen their faces as Weston A. Price when they got that piece of news.

The study findings came out exactly the way any sensible person would have expected, given the known science:

[P]articipants went through three eight-day phases during which they consumed pasteurized milk, raw milk, and soy milk. Gardner notes that "the severity of the symptoms was virtually identical for the raw vs. pasteurized milk, while the symptoms of the soy milk were quite a bit, and statistically significantly, lower."

Raw milk = pasteurized milk in producing symptoms of lactose intolerance. Science!

Gumpert desperately backpedals to find reasons to discount the study as much as possible. It was small, only of 16 people. Gardner responded, "However, despite the small sample size, the results are remarkably consistent. I do not think the sample size proved to be a problem for the study, and that a larger study would have generated the same overall finding, just more strongly."

Gardner attributes the small size of his study to exactly the same problem I spent a whole month writing about in my series of posts about the NIH State of the Science Conference on LI. It's really, really hard to find people who show symptoms to lactose in the laboratory, no matter how horrible they claim their symptoms are in daily life. It's a mystery why this should be. That's the Phase 2 that really needs to happen, not yet another study on why raw milk turns out to contain exactly the same amount of lactose as um, milk.

I realize this won't stop the craziness. A Mark McAfee of Organic Pastures Dairy Company, another raw milk advocate who co-sponsored the study, was already being quoted by Gumpert babbling something scientifically incoherent. Raw Milk is a religious belief. True Believers are not susceptible to facts that contradict their beliefs.

I have a True Belief of my own. That those of you who follow this blog regularly have learned enough about science to dismiss the irrational beliefs of advocates.

So repeat after me today's science lesson: Raw milk contains exactly as much lactose as pasteurized milk. It will produce the same symptoms ounce for ounce in those who are LI. It contains no magical properties that neutralize the lactose. If you get symptoms from pasteurized milk, you will get the same symptoms for an equal quantity of raw milk.

Simple and scientific. Spread the word.

Good General Article on Lactose Intolerance

Shirley S. Wang wrote a nice piece in the Wall Street Journal on lactose intolerance.

Most people continue to produce some lactase, but at much-diminished levels. After they reach their individual threshold and can no longer break down lactose, it passes intact through the intestine until it reaches the colon, where it is finally fermented by the bacteria that reside there. As the bacteria do their job, they produce gas as a byproduct, which causes discomfort and pain as well as symptoms such as cramping and diarrhea.

Training the Bacteria
Some people, after diagnosing themselves, cut out regular consumption of dairy—which can potentially make symptoms worse when they do consume it. The bacteria in the gut can become less efficient at processing lactose if they aren't continually asked to do it. Conversely, people can train the bacteria to tolerate more dairy if they consume it regularly.

She goes on to talk about some of the genetic research into lactose intolerance. In fact, it's clear that she did the interview with Eric Sibley, an assistant professor of pediatrics at the Stanford University School of Medicine, and then wrote an article to justify it.

It's telling that even a well-written, informed article such as this can have so much wrong with it.

Amazingly, Wang never mentions that lactase pills have been available for decades and they are far more effective for far more people than trying to retrain the gut bacteria.

And then there's this:

Dairy products that have gone through some processing, such as cheese and ice cream, tend to have less lactose because the fermentation process breaks some of it down. But those with an intolerance should keep an eye out for lactose that has been added to products like cookies by reading the food label, says Gilman Grave, acting director of the National Institute of Child Health and Human Development's Center for Research for Mothers and Children.

Keeping an eye on ingredients lists is certainly important. But what's that about ice cream being fermented or having less lactose? That's completely wrong. She might have been thinking about frozen yogurt, but that's an extremely odd mistake to make.

We have a long way to go.

Restarting Milk Drinking if You're Lactose Intolerant

I know, I know. You're all tired of my finding silly things that people say on the Net and correcting them. (Like the doctor - a doctor! - who wrote "Only IndoEuropeans (and one small tribe in Uganda) are able to digest milk without problems." Aarrgghhh! Every culture has at least some people who are lactose tolerant. And there are many tribes in Africa who have historic milk cultures and so can drink milk.)

So it's really nice when I can find somebody who's knowledgeable and can explain things and who even says something new and interesting that I didn't know before.

Like Dr. Barry Starr of Stanford University whose Ask a Geneticist column answers a question I get frequently.

I read that lactose intolerance is caused by a genetic mutation. I previously consumed dairy, but have been a vegan for over a year now. I have heard some vegans say that they couldn't return to drinking dairy after being vegan for a long time because their body built up an immunity to it.

But if lactose intolerance is genetic, how is this possible? Are there multiple ways to build or weaken your tolerance for dairy?

Starr gives a good basic introduction to LI and then gets to the guts of the question.

So, what might be going on with your vegan friends?

I can think of a few possibilities. First off, lactase is only made in certain cells in the lining of your intestine. These cells are the only ones that can read the lactase recipe.

So if anything happens to them, then you can get temporary lactose intolerance until the cells return to normal. Things like gastro-enteritis or being allergic to wheat can cause this form of lactose intolerance. I haven't heard of diet affecting these cells though.

Another possibility is maybe something happened to the bacteria in their gut. Even people who make no lactase can tolerate a little milk in their diet. Most likely this is because of some beneficial intestinal bacteria.

These bacteria can digest milk for us in a way that doesn't cause discomfort. Certainly things like antibiotics can give someone temporary lactose intolerance. How might a diet change affect these bacteria?

Our gut is a battleground—a place of ferocious competition between lots of different kinds of bacteria. They are all trying to crowd each other out and they'll use any advantage they have.

Let's say some of the bacteria in your gut can easily digest milk. When you drink milk, they have an advantage over the other bacteria and so happily divide, making more of themselves.

Once you stop drinking milk, their ability to easily digest milk may become a liability. To digest milk, bacteria actually have extra DNA that lets them do it. The extra DNA means it takes a little longer for that bacterium to divide because it needs to copy all of its DNA first.

Now this is no big deal when they are awash in milk. The ability to digest milk more than compensates for the extra DNA. But when there is no milk, they slowly lose out to bacteria that can't digest milk. Or they get rid of that extra DNA and lose the ability altogether.

Either way, when you stop drinking milk, you may lose your ability to digest it because your bacteria lose their ability. I am not sure how big an impact something like this might have on someone's ability to drink milk. But it is a possibility...

Finally, it may be that it is a coincidence, the timing of the vegan diet and lactose intolerance. As I said before, people lose their ability to digest milk at different times of their lives. It may just be that some of your vegan friends happened to become lactose intolerant over the course of the time they were vegan.

That is the same answer that I always give people (phew!) and like Starr I think the real answer is either the second or third possibilities. That bit about the extra DNA on the bacteria was new even to me, though. It helps to be a expert expert.

Pizza Fusion Goes Green

No, not that kind of green pizza. Save that for St. Patrick's Day.

Environmentally green.

A press release from the Pizza Fusion chain announces that:

Over the next six months, Pizza Fusion, the leader in environmentally sustainable restaurant practices, will be opening several new locations throughout the south and northeast United States, including Palm Beach Gardens, Florida, Atlanta, Georgia, Pittsburgh, Pennsylvania and northern New Jersey; introducing all four states to their first ever LEED certified restaurant establishments. Through several area development and individual franchise deals, entrepreneurs are finding value into bringing Pizza Fusion's sustainable approach to organic food service to their communities.

What's LEED?

The Leadership in Energy and Environmental Design (LEED) Green Building Rating System™ encourages and accelerates global adoption of sustainable green building and development practices through the creation and implementation of universally understood and accepted tools and performance criteria.

LEED certification provides independent, third-party verification that a building project meets the highest green building and performance measures. All certified projects receive a LEED plaque, which is the nationally recognized symbol demonstrating that a building is environmentally responsible, profitable and a healthy place to live and work.

But it's pizza. Why should we care? Because Pizza Fusion offers:

health conscious alternatives for people with selective diets and food allergies, including gluten-free, vegan and lactose free options.

Those include:

Gluten-Free Pizza
We cater to many customers with Celiac Disease with our gluten-free crust that is not only wheat-free, but also dairy-free. We use a mixture of garbanzo bean, fava bean and rice flour to make our gluten-free pizza crust, and our sauce and cheese are gluten-free as well. Our Celiac friends are always happy to know that they can order almost any topping gluten-free, excluding only barbeque sauce and sausage. Our gluten-free pizza is one of the best on the market. Its great taste is a reflection of our dedication to using quality ingredients and spending the time and energy to perfect our products.

We also serve a variety of salads and melt-in-your-mouth gluten-free brownies to accompany your gluten-free pizza, as well as offer a gluten-free beer made from Sorghum instead of barley. There are many options at Pizza Fusion that fit the special dietary needs of the Celiac community.

Vegan & Vegetarian Options
We proudly offer a truly vegan soy cheese that is casein-free to accompany our wide variety of organic veggie toppings. Our sauce and dough is always Vegan. We make vegetarian wraps and sandwiches, salads, and breadsticks, and we have vegan brownies for dessert that are oh so good!

Lactose-Free Cheese
Our vegan cheese is dairy and casein-free, making it a tasty option for those with lactose intolerance or anyone looking to cut dairy out of their diet. It is soy-based, and we get rave reviews from adults and kids alike on its great taste.

LI Celebrity Alert: Denise Lewis and Rachel Hunter

The Brits are at it again. Three million Britons are suffering from "imaginary" food intolerances, according to researchers.

An article at ThisIsLondon.co.uk reports that up to 12 million Brits - that's 20% of the population - claims to have a food intolerance of some sort. It's not even clear whether they mean they have allergies or true intolerances; apparently they're using the terms interchangeably. But what can you expect when:

One in 50 of the 1,500 men and women polled in a survey on food intolerances decided they suffered from an intolerance on hearing a friend's diagnosis.

No such article is complete without quoting celebrities for their views. Fortunately, we get a fairly intelligent set of quotes.

Olympic gold medalist Denise Lewis mistakenly tried self-diagnosis as she attempted to find the cause of the stomach problems that had plagued her for years.

"I've suffered from irritable bowel syndrome-related symptoms for 13 years and these have affected my performance on and off the track," she said.

"I was often guessing what could be wrong with me and eliminating a range of foods I thought could be the problem."

However, she discovered what the problem was after taking a food intolerance test.

"I found out I was intolerant to cow's milk, egg yolk and garlic.

"Since reducing these from my diet, I've not suffered my usual bloating and stomach cramps, have more energy and feel brighter and lighter.

She's not alone.

Research by Norwich Union Healthcare found that 19 per cent believe they have a gluten intolerance, such as that suffered by TV presenter Carol Vorderman, while 18 per cent claim a lactose intolerance like that of Rod Stewart's ex-wife Rachel Hunter.

That's right. "Stacey's Mom" is LI.

Answers to Questions from Readers, part 10

Q. What is whey? I heard it was the byproduct or waste water from cottage cheese. I've noticed that cookies or items with whey seem to bother me more than others.

Milk separates into lactose (milk sugar), whey proteins, casein proteins, water, fat, and a few vitamins and minerals. Most cheeses, not just cottage and other soft cheeses, are predominantly hardened casein. The remaining liquid is known as whey. It has some of the milk's proteins and almost all of the sugar. Commercial bakers love whey because it is indeed a cheap waste product, but one that gives a product many of the same nutritional and taste benefits of whole milk. Most commercial whey is dried, meaning that it is roughly 50-75% pure lactose and the rest mostly whey protein. If you are lactose intolerant, whey is one of the worst ingredients to encounter on a label. Most allergies seem to be to casein, but many people are allergic to the whey proteins as well. And of course, since the majority of the world's population is LI, by sheer chance many of them have protein allergies as well. It's not clear which is your problem, but you should avoid whey on a package label. See my SuperGuide to Dairy Products for more info on dairy.

Q. Do eggs contain lactose?

For some reason, probably since eggs are so often found in the "dairy" case in supermarkets, many people believe that eggs are dairy products and need to be avoided. This is completely false. Eggs come from chickens, not cows. They contain absolutely no lactose. (This is true of most mayonnaise as well.)

Q. Why does the lactase that is in me when I am born, decrease when I grow older?

Here's what one researcher had to say:

"Speculation as to why the lactose gene 'turns off' is a fascinating topic. One theory suggests that lactase deficiency evolved early in mammalian history, perhaps 75 million years ago, as a means to facilitate weaning and shorten the dependence of the child on the parent for lactation. The gas and diarrhea produced by lactose malabsorption would stimulate the child to become weaned. One competing theory suggests that lactose malabsorption in adults prevents competition of adults with infants for food (who can only digest milk early in life), and another theory proposes that lactose intolerance evolved as a defense mechanism against intestinal infections."

In other words, nobody knows for sure.

Q. My 80-year-old mother has been diagnosed as being LI. I've heard that it was unusual to have this happen so late in life. What do you know about this?

It is unusual, but hardly unknown. Different people are genetically programmed to lose their ability to make lactase at different ages, that's all. (Unless she had some sort of intestinal disease or surgery that might have damaged her intestines. That can cause LI at any age.)