While it seems like everyone is swearing off some food or other these days, we actually know very little about so-called food sensitivities. “The term ‘food sensitivity’ is subjective, and not necessarily a true allergy or intolerance,” says Karen Robbins, MD, Assistant Professor of Pediatrics, Division of Allergy and Immunology at Children’s National Health System.
Allergies cause an immediate measurable immune response, and intolerances are delayed, reproducible symptoms often caused by the lack of an enzyme or other factor necessary to digest a food. For example, some people don’t have the lactase enzyme necessary to digest dairy. Others may react to chemicals naturally found in foods, like caffeine (in coffee, tea, sodas, and energy drinks); salicylates (in many foods including dried fruits, berries, peppers, processed meats, almonds, and olive oil); or histamine (in alcohol, pickled foods, aged cheeses, and smoked meats). The term food sensitivity is often used interchangeably with food intolerance.
Gluten is a good example of how confusing food reactions can be. According to a 2015 article in the World Journal of Gastroenterology, people with celiac disease, wheat allergy, and non-celiac gluten sensitivity can have similar symptoms. But while celiac disease and wheat allergy have been extensively studied and can be diagnosed with specific tests, non-celiac gluten sensitivity is not well understood and can only be diagnosed by ruling out other conditions.
What to Do?
There’s a lot of hype about food sensitivities and some for-profit companies claim they can diagnose your problem. If you have symptoms you believe are related to what you eat, it’s important to see a doctor. An allergist can perform skin prick or blood tests. If these tests rule out a food allergy, don’t stop there. “I am confronted daily by patients suffering from gastrointestinal complaints, like bloating and abdominal discomfort thought to be related to food allergies,” says Clifford Bassett, MD, Founder and Medical Director of Allergy and Asth-ma Care of NY. “In a small percentage of cases, we do uncover specific food allergies, but food allergies are not the cause of gastrointestinal complaints in the majority of cases. Only about 3 percent of adults suffer from food allergies.”
Bassett recommends your next stop be a gastroenterologist. “GI symptoms can be caused by a wide array of conditions, including reflux; carbohydrate, gluten or lactose intolerance; and irritable bowel syndrome, to name a few,” says Bassett. GI doctors can perform tests for celiac disease and common food intolerances.
Narrowing it Down
If you don’t have celiac disease or a diagnosable allergy or intolerance, food can still cause intestinal upset, skin reactions, and even headaches, but figuring out trigger foods can be tricky. “There are many food-related tests available that are used without strong evidence behind them, so patients should be careful,” cautions Robbins.
If you can’t get a diagnosis from an allergist or GI doctor, a registered dietitian can help you with an elimination diet. The gold standard for figuring out if foods are causing your discomfort, this diet involves not eating specific foods for a period of time to see if symptoms improve. If adding the food back causes a return of symptoms, you have an intolerance (or sensitivity) to that food.
The important thing is getting help to ease your symptoms. “Many people feel better after making changes to their diet,” says Robbins, and that’s what matters.
—Judith Thalheimer, RD