If there’s one part of our health journey that has left us scratching our heads more than anything else, it’s food sensitivities. And guess what? We’re not alone. Food sensitivities and intolerances are becoming more common by the day. Some reactions are mild and manageable, but others can be severe and, honestly, pretty damn bizarre. 

Anyone else feel a surge of blind rage after eating onions? Or mood swings from munching on blueberries? The struggle is REAL and it’s about more than just some uncomfortable gas.

If you, like Trever and I, have tried every dietary intervention, detox, and gut healing protocol out there, only to be left with about five ‘safe’ foods and still find yourself screaming, “Why do I have so many food sensitivities?!” this article is for you. 

Read on to discover what food sensitivities are, their signs and symptoms, potential causes, our craziest experiences, and whether a dysregulated nervous system might be behind your food reactions.

What are Food Sensitivities?

Food sensitivities are those annoying reactions to certain foods that don’t involve the immune system’s immediate IgE response (unlike allergies). They usually happen because our immune system loses tolerance to the protein sequences in some foods, leading to a whole bunch of physical and mental symptoms.

How are Food Sensitivities Different from Food Intolerance and Allergies?

Food sensitivities differ from food allergies and intolerances in several ways:

Immune Response

  • Food Allergies: Involve an immediate and severe immune system response, often leading to anaphylaxis.
  • Food Sensitivities: Do not typically involve the immune system’s immediate response and are not life-threatening.
  • Food Intolerances: Are mostly experienced in the lumen of the gut and may be related to issues digesting certain components of food e.g lactose intolerance, FODMAP intolerance, gluten intolerance.

Onset

  • Food Allergies: Symptoms occur within minutes to a few hours after exposure to the allergen.
  • Food Sensitivities: Symptoms can be delayed, occurring hours or even days after consuming the offending food.
  • Food Intolerances: Are usually experienced immediately or within 2-4 hours of consuming a particular food.

Mechanism

  • Food Allergies: Mediated by immunoglobulin E (IgE) antibodies.
  • Food Sensitivities: Mediated by immunoglobulin IgG and IgA
  • Food Intolerances: Mechanisms vary and can include poor digestive enzyme production, bacterial overgrowth or autoimmunity.

Signs and Symptoms of Food Sensitivities

Food sensitivities can show up in all sorts of ways, messing with both your body and your mind.

Symptoms may include

Physical Complaints such as:

Digestive Issues:

  • Bloating
  • Gas
  • Diarrhea
  • Constipation
  • Abdominal pain

Skin Problems:

  • Eczema
  • Acne
  • Itchy skin
  • Hives

Respiratory Issues:

  • Congestion
  • Excessive mucus production
  • Postnasal drip

Cardiovascular Symptoms:

  • Rapid heartbeat
  • High blood pressure

Mental and Emotional Issues:

  • Mood Swings
  • Anxiety
  • Depression
  • Brain Fog
  • Cognitive Impairment
  • Irritability
  • Insomnia
  • Difficulty Concentrating

As well as:

  • Joint Pain and Muscle Aches
  • Fatigue and Lethargy
  • Weight Gain or Inability to Lose Weight
  • Headaches and Migraines

What Causes Food Sensitivities?

Several factors might be behind your food sensitivities. Here are some of the usual suspects:

  • Maldigestion: If your body isn’t producing enough digestive enzymes or stomach acid, food particles don’t get properly broken down, and this can trigger an immune response.
  • Leaky Gut Syndrome: When your intestinal lining gets a bit too permeable, undigested food particles can sneak into your bloodstream, causing immune reactions.
  • Dysbiosis: An imbalance in your gut microbiota can mess with digestion and lead to food sensitivities.
  • Inflammatory Responses: Chronic inflammation in your gut can make you more sensitive to certain foods.

Can Nervous System Dysregulation Cause Food Sensitivities?

The ANS keeps many bodily functions in check, like digestion, immune response, and how we handle stress.

Nervous system dysregulation may be a big player in developing food sensitivities. When the autonomic nervous system (ANS) is out of whack, it can make you super sensitive to all kinds of stuff, including food.

So, how might a dysregulated nervous system lead to food sensitivities?

  • Stress Response: Chronic stress messes with our hormones – specifically cortisol. This can wreak havoc on the immune response in your gut, leading to intestinal permeability (leaky gut) and inflammation – making food sensitivities more likely.[*]
  • Immune Dysregulation: A dysregulated ANS can impair the immune system’s ability to tell the difference between harmless food molecules and actual threats, leading to immune reactions to food.[*][*]
  • Gut-Brain Connection: The gut and brain are intimately connected through the gut-brain axis. If the nervous system is out of sync, this connection can get disrupted, leading to mood swings and digestive issues, which certain foods can trigger or make worse.[*]

How to Identify Food Sensitivities

Figuring out food sensitivities can be tricky, especially when your symptoms are all over the place. Here are some tips to help you nail it down:

  • Keep a Food Diary: Keep a detailed diary of everything you eat and drink, along with any symptoms that pop up afterward or in the following days. Try to identify any patterns.
  • Elimination Diet: Cut out suspected trigger foods from your diet temporarily and then reintroduce them one at a time, paying close attention to how your body reacts. The AIP protocol, GAPS, Whole30, and Low FODMAP diets are great places to start.
  • Professional Guidance: Get some expert advice by consulting a healthcare provider or registered dietitian. They can offer guidance and food sensitivity testing to help you out.

Food Sensitivity Testing Near Me: Should I Be Tested?

Food sensitivity testing can help you figure out your triggers. Nowadays, it’s easier than ever to test for sensitivities right at home with online test kits—no need to visit a practitioner in person. Brands like Everlywell offer reliable kits that analyze your body’s IgG (immunoglobulin G) response to different foods, helping you pinpoint potential culprits.

However, keep in mind that at-home test kits might have some limitations. False negatives and positives can still happen. For instance, many tests check for immune responses to raw foods, but we usually eat these foods cooked, like eggs. Heat changes the protein structure, and since your immune system reacts to these structures specifically, you want to make sure you’re testing reactions to foods in their typical state.

Although no test is 100% fool proof, the gold standard in the industry is the Cyrex Array 10, which can distinguish between raw and cooked foods, among other things. Cyrex also tests for both IgA and IgG antibodies, so you can determine a broader range of sensitivities.

Cyrex tests are readily available online, so there is no need to visit a practitioner in person. You will however need to order your test via a licenced Cyrex practitioner so that they can help you interpret your results and next steps.

It’s also worth noting that these tests are not designed for testing allergies, or detecting celiac disease.

Can a Gastroenterologist Test for Food Sensitivities?

Gastroenterologists can diagnose specific food intolerances and autoimmune-related digestive conditions through tests such as:

  • Lactose Tolerance Test
  • Celiac Disease Blood Tests
  • Endoscopy and Biopsy

However, for other types of food sensitivities, additional blood testing may be necessary.

It’s worth noting that these tests may not detect sensitivities linked to nervous system dysregulation, as they primarily address digestive disorders.

Identifying Food Sensitivities Related to Nervous System Dysregulation

If your reactions to food appear erratic, have no obvious cause, and all other tests and approaches have failed, it’s worth considering a dysregulated nervous system. 

Here are some common signs that your food sensitivities may be the result of nervous system dysregulation:

  • Erratic and Inconsistent Reactions: You experience different symptoms, to varying degrees – even after you consume the same foods.
  • Anxiety and Stress Responses: Your reactions to food are heightened during periods of stress or anxiety.
  • Bizarre Symptoms and Reactions: Your food-based issues don’t just consist of the typical digestive symptoms associated with food intolerance. You also notice changes to your mood, sleep and hormones, etc.

Healing Food Sensitivities Caused by Nervous System Dysregulation

Healing food sensitivities caused by nervous system issues means getting your autonomic nervous system back on track.

Here are some simple ways to begin:

  • Mindfulness and Relaxation: Try meditation, deep breathing, or progressive muscle relaxation to ease stress and balance your nervous system.
  • Lifestyle Adjustments: Regular exercise, consistent sleep patterns, and minimizing stress can all help regulate your nervous system.
  • Gut Support: Maintain a healthy gut with a balanced diet, probiotics, and prebiotics to reduce strain on your nervous system.

What If I Need More Help?

If your food sensitivities are seriously messing with your menu options, and self-help techniques aren’t cutting it, it might be time to get some specialized help to boost your nervous system resilience.

Check out these awesome programs and protocols that could really make a difference:

Our Food Sensitivity Experience

Alright, let’s take a breather from all the serious stuff and share a chuckle. I bet some of you can totally relate to this. While food sensitivities are no laughing matter and should be taken seriously, sometimes you have to find the humor in the situation. Here are some of our own food-related reactions:

Rutabaga: Turned Trever into a grumpy bear. Watch out if he’s ever near one.

Cherries: Sent me into a late-night spiral of repetitive thoughts—work tasks, or songs stuck on a never-ending loop.

Corn chips: Gave me achy hips. Seriously.

Apples: After months of daytime fatigue and a buzzing head, Trever ditched apples—and poof, those symptoms vanished.

Fructans: The arch-nemesis for both of us. They made Trever sad and tearful and me raging mad. Nobody would want to be around us if we’d shared a plate of onion rings.

How We Healed Food Sensitivities

After battling food sensitivities for years, we finally turned things around when we got serious about regulating our nervous systems. Once we did, things started improving fast.

Our big breakthroughs came with programs like SSP and DNRS, knocking our food and chemical sensitivities down by about 60%.

We also got heavily into Dr. Linnea Passaler’s course for everyday nervous system maintenance.

These practices not only eased a ton of symptoms, like:

  • Insomnia
  • Mood swings
  • Hormone imbalance
  • Gut issues
  • Skin troubles
  • Fatigue
  • Brain fog
  • Anxiety

—but they also let us bring in helpful supplements we couldn’t handle before. That helped reduce our symptoms further by letting us build in other good habits like detox routines and digestive enzymes.

Getting our nervous system in check was a total game-changer, bringing us back to a healthier, more varied, and balanced diet.

Food sensitivities linked to nervous system issues can be a challenge, but they’re not unbeatable. By recognizing symptoms, exploring testing options, and trying techniques to balance your nervous system, you can take steps toward feeling better and expanding your food choices again.

Contributors

  • Emma Clark, BA (Hons) - Author

    Emma Clark holds a BA (Hons). She is EMDR and EFT trained, has a level 2 certification in Reiki, and is a certified Unyte Safe and Sound Protocol provider. Emma cut her teeth in the health and dieting niche before co-founding Regulate Co. She has an unhealthy obsession with Bon Jovi, aspires to own 1000 guinea pigs, and feels best in the sunshine with an ice cream in hand.

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  • Anna Marsh, MSc - Scientific Reviewer

    Anna has over 14 years of experience as a health care practitioner. She holds a Masters Degree in Personalised Nutrition, is a fully certified practitioner with the Institute of Functional Medicine and is currently enrolled in her advanced year of Somatic Experiencing. Anna loves swimming in the ocean on the south west coast of England, hiking, training in the gym, eating chocolate, cooking up a storm and hanging out with her little black cats.

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