How many times have you eaten something that "didn't agree with you" and assumed you had ingested bad food that caused food poisoning? It's more likely that your symptoms were caused by a food sensitivity, which can wreak all kinds of havoc on your body. But how can you know for sure? And what should you do about it?
The first thing to know is that food intolerances or sensitivities are uncomfortable and bothersome – and can be serious. But unlike true food allergies, they aren’t usually life-threatening. Also, although the two terms are often used interchangeably, food intolerance and food sensitivity are technically different. Food intolerance is the inability to digest or process specific foods – such as lactose. In fact, lactose intolerance is the most common food intolerance – affecting more than 60% of the population to some degree -- and a whole industry of lactose-free dairy products and enzyme supplements has emerged as a way to help people avoid the unpleasant symptoms. Food intolerances generally produce gastrointestinal symptoms that occur within a few hours of eating including:
- Diarrhea
- Heartburn
- Abdominal pain
- Gas
- Bloating
- Upset stomach
A sensitivity to a specific food, on the other hand, appears to create an immune response in your body – but it’s much slower than the response to a food intolerance. A food sensitivity is often due to an imbalance in your gastrointestinal tract, and can cause whole-body symptoms such as:
- Stomach pain
- Itching
- Joint or muscle pain
- Fatigue
- Rashes
- Brain fog
- Headaches
- Sneezing or a running nose
- Mood changes
- Sleep disturbances
If you suspect you have a food intolerance or sensitivity, the first step is the same: identifying the offending item. That’s often easier said than done, especially with food sensitivities where the response to a specific food may be delayed for up to three days. Further complicating matters, food intolerances and sensitivities can change throughout our lives, so you may have a reaction to something that you’ve eaten hundreds of times before without any problem. And, while it’s certainly possible to outgrow a sensitivity, most of us actually become sensitive to more foods as we age. Thus, managing your diet and knowing which items to avoid can become an ongoing challenge.
The first step is keeping a detailed food diary for a few weeks, along with any adverse reaction you may have. If you notice immediately that a certain food causes problems every time, you should eliminate it immediately. If you see a pattern of symptoms associated with eating gluten (a protein found in grains such as wheat, barley, rye) talk to your doctor to rule out Celiac disease.
The next step is to try an elimination diet. An elimination diet can be difficult, and you should always talk to your doctor before making any significant changes to your diet. There are a wide range of elimination protocols, including popular eating plans such as The Whole30 diet, the autoimmune protocol diet, and the low-FODMAP diet. Because the choices are confusing and the process is so complex, we recommend working with a registered dietitian to help you select the best approach and monitor your results.
Keep in mind these diets must be followed for at least one month, and ideally up to three months. If you are intolerant or sensitive to any foods, you should see improvement during this time. After following a strict elimination diet for a few months, you can move to the next phase, which is reintroducing certain foods. (Your dietitian will be extremely helpful in this phase.)
Reintroduction needs to be done very slowly and deliberately. You can add one food at a time, then wait three days to see if you have any reaction. If not, you can go ahead and add another food. Resist the temptation to move quickly or add more than one food at a time: if you have a reaction it will be impossible to tell what triggered it. It’s also critical to keep up with your food diary during this time so you can record exactly what you eat, what symptoms you may have experienced, and when the symptoms appeared. Armed with this knowledge, it will be easier to construct a diet that is healthy and nutritious – but doesn’t include your problematic foods.
One final note: as mentioned early, food allergies are very different from intolerances and sensitivities, and they can be life threatening. They can also develop very suddenly, even if you’ve never had a problem before. If you ever experience serious symptoms of a food allergy, such as wheezing, swelling of your lips, tongue or throat, or shortness of breath, call 911 or visit your nearest emergency room immediately.
This article appeared in the September 2024 edition of the HealthPerks newsletter.
