Food Allergy and Intolerance Guide

It’s tough to host a dinner party these days, given everyone’s digestive challenges: No gluten. No dairy. No sugar. No wine or beer with sulfites. What’s going on?

Gastrointestinal experts call it food intolerance, and it’s increasingly an issue. Some estimate that 10 to 25 percent of Americans have a sensitivity to at least one food, while others say the prevalence is much higher.

“Percentages are only guesstimates at this point,” explains Steven M. Dandalides, M.D., a spokesperson for the American College of Gastroenterology and an assistant clinical professor at Eastern Virginia Medical School in Norfolk. “Judging by the number of people who come to see us, this seems to be a common problem.”

When seemingly good foods are sidelined, it’s hard not to question whether food intolerance is really a problem of the gut or simply an excuse for picky eaters. New research points to just how common it is — and how to cope if you’re diagnosed.

Intolerance Versus Allergies

To understand what food intolerance is, you first have to understand how it differs from allergies. An allergy is an immune-system response in which your body mistakes a certain food for a harmful invader and creates antibodies to fight it.

Symptoms can be mild or life-threatening — from nausea and hives to shortness of breath and anaphylaxis — and tend to come on immediately. According to the American Academy of Allergy, Asthma, and Immunology, only 3 to 4 percent of adults in the U.S. have a true food allergy.

Unlike an allergy, a food intolerance is a response from the gastrointestinal system. When certain foods are poorly absorbed from the intestines into the bloodstream, the result can be symptoms like gas, bloating, diarrhea or constipation, nausea, or abdominal pain one-half to eight hours after consumption.

Another big difference: Food intolerances are often but not always dose dependent. This means that even if you’re predisposed to intolerance for a food, you can likely eat a certain amount of it without experiencing an unpleasant GI reaction — and that dose varies by individual.

Another misconception: You don’t necessarily have an intolerance if you get gassy and bloated after drinking milk or eating pasta. (Though these days, having a food intolerance seems almost fashionable.) You’ll need to see a medical professional to determine whether you really have a food sensitivity, and if you eliminate suspect foods without seeing a doctor, you’ll likely miss out on vital nutrients.

“If you’re not gluten intolerant, a gluten-free diet is not healthier,” stresses Stefano Guandalini, M.D., a food-intolerance specialist who is director of the University of Chicago Celiac Disease Center. Restricting your diet unnecessarily can keep you from getting an accurate diagnosis of a more serious condition.

Why the Rise?

There’s been a great deal more food-intolerance research in Europe than in the U.S., yet the cause is still somewhat mysterious. There are a couple of respected hypotheses: One is that as we evolved from hunter-gatherers and began eating foods we produced ourselves, such as wheat and cow’s milk, some of us weren’t able to adapt and developed intolerances.

Other experts say that the food we eat today is too “clean.”

“We don’t get exposed to good bacteria found in places like soil anymore,” says Scot Lewey, D.O., a Colorado Springs gastroenterologist and fellow at the American College of Gastroenterology.

Chemicals purify our water; we don’t eat fresh-picked produce; our meat has been dosed with antibiotics to keep it disease-free. Plus, we’re now more likely to consume commercially processed multi-ingredient foods, increasing the number of potential irritants.

Anxiety and poor lifestyle habits can also take a toll on your GI tract.

According to the American College of Gastroenterology, the primary intolerance culprits are foods containing lactose, gluten, and fructose. Here’s how they all break down. If one of these descriptions resonates with you, you might want to make a doctor’s appointment.