It has become more and more clear that not everyone does well on the same foods. Some reactions happen immediately, and some take time to really set in. How much do you know about food intolerances?
Today, I want to take a deep dive into what makes up a food intolerance and the most common culprits that you absolutely need to know about.
“One man’s meat is another man’s poison” – Titus Lucretius Carus, which became an expression coined by him in the very first century (BC). It has been that way for a long time, that not everyone does well on the same foods.
The problem is that while some reactions are immediate, others really take their time. This delay is what makes it hard to know which foods are best for you. These kinds of reactions can actually be casually referred to as sensitivities, intolerances or allergies.
Allergies are important to consider, but it is just as important to know that not all intolerances are allergies. An allergy is defined as a chronic condition involving an abnormal reaction to ordinary harmless substances1. These can include:
Bottom Line: Unlike other types of food disorders, like intolerances, food allergies are “IgE mediated.” This means that your immune system produces abnormally large amounts of an antibody called immunoglobulin E — IgE for short. IgE antibodies fight the “enemy” food allergens by releasing histamine and other chemicals, which trigger the symptoms of an allergic reaction.
Intolerances can be caused by other immunoglobulins and their subtypes, such as IgA, IgD, IgG or others. They might also involve reactions of the gut flora to elements of foods, and/or by the neurologic responses to food proteins.
Bottom Line: When it comes to using the term sensitivity or intolerance, I always like to go with the term intolerance. It’s used by more people and, to me, sensitivity sounds like the patient is being taken less seriously. This is a real problem, so we should take it seriously.
Some reactions are pretty obvious, and they can be as immediate as a train wreck. This could include anaphylactic allergic reactions to nuts or shellfish, in which the person can risk death if they are not treated properly.
These reactions can come on in a matter of seconds of exposure to certain foods.
Other reactions may have no apparent effects at all, but nonetheless are harmful.
Many who have other versions of celiac disease may have no symptoms and no apparent problems, but they actually have a higher risk for colorectal cancer if they are consuming wheat products on a regular basis2.
Delayed hypersensitivity reactions may cause no apparent distress at the point of the meal, but may increase the tendency towards joint pain, fatigue, skin symptoms and digestive symptoms at random times.
At that point, it can almost be impossible to tell what is causing you to react.
Key Insight: Some delayed reactions can take weeks after being exposed to certain foods. With that sort of timeframe, who knows what foods might be causing you long-term distress. What it comes down to is that food can cause symptoms in ways that are not obvious to me or you in the moment, but can have long-term effects on our health and well being.
During my medical training, I saw dozens and dozens of people who experienced radical improvements to their health by avoiding certain foods. This was even though these foods seemed to cause them no acute distress.
The first clinic that I worked at was actually affiliated with a testing laboratory which did food intolerance testing. I got to see these tests done first hand and I got to understand the technology that taught us about food intolerances.
This experience left me with the respect for how significant hidden food intolerances could be, but also how difficult it was to gather accurate data about them.
Around this same time, a professional golfer traveled to see me with concerns about arthritis. He had osteoarthritis so severe that it was actually ending his career as a player. He wanted to know if food intolerances could be the culprit behind his arthritis.
At this point in my career, I was unsure about whether or not foods could be the sole cause of such a major problem.
I did agree to test him, though, and evaluate his health to find the root cause of his problems. The testing revealed that he was struggling with no major problems, except for a severe intolerance to dairy and eggs.
After agreeing to avoid them completely, I lost touch with this patient. A few years later, he reached out to me to let me know that he had resumed his career and was now touring as part of the Master’s tournament.
He said that he remained free of his symptoms, as long as he avoided those reactive foods.
Bottom Line: We need to respect the fact that food intolerances can lead to major problems with our health, even when we might not expect them. When we get a better idea of the food intolerances our bodies cannot handle, whether or not we know it, we can work towards helping our bodies thrive while excluding those foods from our diets.
The problem with allergies is that we often do not consider just how many people are affected by them. Researchers actually estimate that up to 15 million Americans have food allergies and that it can affect 1 in every 13 children in the country – that is roughly 2 children in each and every classroom3.
Food allergies are not just prevalent, though, they are also on the rise. According to a study released in 2013, by the Centers for Disease Control and Prevention, food allergies among children increased approximately 50% between 1997 and 20114.
Key Insight: The number of people who have a food allergy is growing, but there is unfortunately no clear answer as to why.
Teenagers and young adults with food allergies are at the highest risk of fatal food-induced anaphylaxis. Individuals with food allergies who also have asthma may be at increased risk for severe/fatal food allergy reactions.
There are actually eight foods that account for the majority of all reactions, they include:
Even a trace amount of these types of foods can cause a reaction, which is what makes them so dangerous. Let’s break down some of the most common ones and their relevant statistics.
These tend to develop in childhood and are usually lifelong. In the United States, approximately 3 million people report allergies to peanuts and tree nuts. Studies actually show that the number of children living with peanut allergy appears to have tripled between 1997 and 20085.
These types of allergies begin in childhood, but they eventually may be outgrown over time. In the past, most children grew out of these allergies by school age.
A recent study, conducted by researchers at Johns Hopkins University School of medicine, indicated that children are taking longer to outgrow milk and egg allergies6.
Fortunately, the majority are still allergy-free by the age of 16.
Just like peanut and tree nut allergies, allergic reactions to fish and shellfish also tend to be lifelong. More than 6.5 million adults are allergic to finned fish and shellfish.
When we continue to ingest foods that do not agree with our bodies, it can cause chronic inflammation.
This chronic inflammation can elevate our overall cortisol levels, it can worsen insulin resistance, and it puts our body into “storage” (survival) mode.
Studies have shown that if two groups of people eat the exact same amount of calories, but one group identifies and avoids reactive foods, that group will lose more weight.
That is because for many people, hidden foods are the culprit blocking their success with weight loss.
Bottom Line: Chronic inflammation in your body can lead to weight gain, and you might not even know that it relates back to your food intolerances. In this way, they are hiding in plain sight!
Food reactions are a big part of what drives autoimmune thyroid disease (Read: How to test your thyroid, the definitive guide), such as Hashimoto’s and Grave’s disease.
Reactions place the immune system in an overly reactive state. That means that when someone’s body is genetically prone to attack the thyroid, and if it was carrying toxins, this site and immune response ends up causing the cells to attack the thyroid by mistake.
Key Insight: When it comes to food intolerances, there are a broad array of reactions within the body that trigger an inflammatory response within the intestinal tract. This can include chemicals like histamines and cytokines, which are formed in the intestinal tract and circulate throughout the body. This is ultimately the reason for why so many symptoms can be caused.
There are many symptoms that might suggest you are intolerant and they may be immediate, but they also might take time to set in. Some of these symptoms include:
Bottom Line: Even if you do not expect it, there are lots of symptoms that could relate back to a food intolerance. Are you experiencing any one of these? Then it might just have to do with your body reacting to something you are eating.
That’s the problem when it comes to food intolerances, people of all ages can have them. Although, they are more common in those who have a personal or a family history of allergies or autoimmune diseases.
People with chronic intestinal inflammation, such as Crohn’s disease, ulcerative colitis or irritable bowel syndrome are also more at risk.
Another group who might be at risk are those who have been on medications for long periods of time, especially antibiotics or oral contraceptives. These can actually harm the protective intestinal flora in your gut.
When the intestinal flora is compromised, think of it like a screen door. A screen door is perfect for keeping the bugs out and bringing the fresh, clean air indoors.
When the intestinal lining becomes too thick, it is like the holes in a screen door becoming huge – anything can come flying in to muck up all that fresh air.
The other aspect of this would be having proteins in your diet. Proteins are essentially clusters of amino acids, which are found in large, complex 3-dimensional shapes.
When we digest them well, the big pieces are broken down into tiny little pieces that are easy to absorb. Normally, there are some large undigested pieces that the intestinal lining prevents us from absorbing and is left in our stool.
However, when the lining is too thin the larger pieces also become absorbed. When this happens, they trigger an immune response which creates damage to the intestinal tract.
Some food proteins are harder to break down than others, which is why some foods are more apt to become allergens.
Think about it like this: When you are baking, you need ingredients. These ingredients help you make the dough in your batter stick together. The popular foods to use are wheat (flour), milk and eggs.
Wheat has gluten, milk has casein (Read: Are dairy foods good for you) and eggs have albumin – I call all of these the binding proteins, because they hold things together.
Since they are binding and sticky, they often have larger amounts of undigested amino acid groups that pass through the intestinal tract.
Key Insight: Whenever digestion is not working perfectly, these kinds of foods are more apt to leave undigested protein fragments than other foods.
Here is where we need to make a quick distinction between innate food reactions and functional food reactions.
An innate food reaction is the type that people tend to have long-term, such as peanuts or wheat (in the case of celiac disease). Functional food reactions, on the other hand, occur when someone does not digest food properly which triggers a response.
These types of reactions are important, but you may not be stuck with them long-term.
Estimates range from 10 to 50% of the population. When I typically see someone for health concerns, especially thyroid disease, I always screen them for food intolerances.
I would estimate that, of this population, roughly 70% have at least one food reaction that they did not know about.
Here is the definitive list that you need to keep an eye on when it comes to developing food intolerances:
Which foods are the most common culprits?
Bottom Line: While our bodies might be intolerant to some foods, it is also important to make note of which foods we might be more naturally “intolerant” of – in the sense that we should avoid entirely, because of the effect that they have on our body. This is definitely the case when it comes to something like sugar!
That is an easy one! All you have to do is check out the recent article I wrote about testing for food allergies (Read: The ultimate guide to food intolerance testing).
This will give you more of the information you need to help benefit your body.
Key Insight: Do not blame your food intolerance on something you recently ate, because that might not be the culprit. It is like I always say: test, don’t guess when it comes to your health.
Do you feel like you need to make a change, but do not know where to start? I would love to share with you this free ebook, “35 Natural Hormone Resets” (Click Here).
It will give you the knowledge and tools you need to lead your best life, and to start feeling good today.
1 – https://www.aaaai.org/conditions-and-treatments/conditions-dictionary/allergy
2 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3684421/
3 – https://waojournal.biomedcentral.com/articles/10.1186/1939-4551-6-21
4 – https://www.cdc.gov/nchs/data/databriefs/db121.pdf
5 – https://www.foodallergy.org/file/facts-stats.pdf
6 – https://www.hopkinsmedicine.org/news/media/releases/milk_and_egg_allergies_harder_to_outgrow_hopkins_study_shows
P.S. Whenever you are ready, here is how I can help you now:
1. Schedule a Thyroid Second Opinion with me, Dr. C, Click Here for Details
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4. Check out my podcast Medical Myths, Legends, and Fairytales Here
Dr. Alan Glen Christianson (Dr. C) is a Naturopathic Endocrinologist and the author of The NY Times bestselling Adrenal Reset Diet, The Metabolism Reset Diet and The Thyroid Reset Diet.
Dr. C’s gift for figuring out what really works has helped hundreds of thousands of people reverse thyroid disease, lose weight, diabetes, and regain energy. Learn more about the surprising story that started his quest.
Dr. Alan Christianson
Alan Christianson is a Naturopathic Medical Doctor (NMD) who is a board-certified Naturopathic Endocrinologist with a focus on thyroid disorders. He is the author of The Metabolism Reset Diet and the New York Times bestselling book The Adrenal Reset Diet.
He founded Integrative Health, a physician group dedicated to helping people with thyroid disease and weight-loss resistance regain their health.
He has been named a Top Doctor in Phoenix magazine and has appeared on national TV shows and in numerous print media.
Dr. Christianson resides in the woods by a lake in Northern Minnesota with his wife Kirin.
