Are you struggling with symptoms that are causing confusion and a lot of discomfort? If yes then read on. Before I go in-depth on this topic, I’d like to clarify the difference between food intolerance, allergy and sensitivity:

Food allergy involves the immune system. If you eat something you are allergic to your immune system has indentified that particular food as a foreign invader. It triggers an immune response and produces antibodies known as IgE. Common food allergens are tree nuts, peanuts, seafood, eggs, wheat, milk and soy. The immune reaction can result within minutes or hours of the allergen entering the body. Food allergies can cause mild symptoms or a serious reaction known as anaphylaxis. Symptoms can be skin swelling, tingling or itching of the mouth, wheezing or difficulty breathing, dizziness or abdominal pain, nausea or diarrhoea.

Food intolerance occurs when the digestive system struggles to breakdown certain foods. A common food intolerance example is lactose, which is a type of sugar found in dairy products. Lactose intolerance is often the result of a deficiency of an enzyme known as lactase. Symptoms of food intolerance can range from bloating, diarrhoea and abdominal cramps.

Food sensitivity is similar to a food allergy but instead of triggering a potential life threatening IgE mediated response, a IgG or IgA response is triggered. Symptoms of food sensitivity can vary greatly, some examples include joint pain, rashes, hives, brain fog, headaches and digestive symptoms such as bloating. Common food sensitivities include gluten, caffeine and food chemicals such as histamine.

Coeliac disease is an auto-immune disease where gluten causes an inflammatory reaction which makes people with the condition very sick. Gluten sensitivity is not the same as coeliac disease. Anyone who has coeliac disease must strictly avoid gluten, including cross-contamination when preparing food.

How to approach food sensitivities

The first step to approaching food sensitivities is by identifying the problematic food. Working with a nutritionist is the most effective way to work out which foods are causing problems.

Once you have removed the offending foods, identifying the underlying causes is the next step. This may involve testing, or addressing insufficiencies within the digestive process such as enzymes. or specific nutrients. Other problems could be an imbalanced microbiome (known as dysbiosis), impaired detoxification or small intestine bacterial overgrowth (SIBO).

Another aspect to consider when experiencing food sensitivities is hormones. Thyroid, estrogen, progesterone and cortisol all play an important role in gut health and can contribute to food sensitivities.

Cortisol, the stress hormone

Chronic stress is a risk factor for developing sensitivities to certain foods. Cortisol is known as the stress hormone. The nervous system and the immune system are closely linked and can influence each other; for instance, the nervous system regulates immune function through triggering the hypothalamic pituitary adrenal axis (HPA) in the body which release cortisol into the blood stream (1).

Cortisol can decrease secretory immunoglobulin A (slgA) which is a crucial part of the immune system found throughout all mucosal barriers within the body, including the gut. SlgA can be considered as the first line of defense as it protects us against foreign invaders such as pathogenic bacteria (1). When slgA is reduced, the lining of the intestine can become compromised and can become permeable, otherwise known as ‘leaky gut’ (1).

When there is a leaky gut, proteins that wouldn’t normally be allowed to pass through, enter the bloodstream. Once these proteins enter the bloodstream, our immune system can mount an inflammatory response and can manifest with a range of symptoms ranging from mood symptoms such as depression and anxiety, brain fog, headaches and joint pain.

When we are constantly stressed, whether it’s emotional, physical or psychological, cortisol is released. One of the most stressful events our body can deal with is blood sugar imbalance. A common symptom of blood sugar imbalance is low blood sugar or hypoglycemia. Common symptoms of hypoglycemia include feeling ‘hangry’, shakiness, anxiety and low energy levels (2). When we enter into this state, cortisol is released from our adrenal glands, to help stabilise our blood sugar (2).

What this means is, if a person is yo-yo dieting, consuming excess caffeine, or eating a high sugar, low fibre diet (a typical western diet) this will cause blood sugar dysregulation, leading to a crash in blood sugar at certain times of the day (often mid-afternoon) which leaves the person craving sugar and reaching for a quick snack that spikes their blood sugar again.

If the pattern of stress isn’t resolved, over time it places pressure on the adrenals and decreases slgA levels which contributes to the development of intestinal permeability (leaky gut) and food sensitivities.

PCOS

A common hormonal imbalance is PCOS. Women who have insulin resistant PCOS will have a pattern of blood sugar imbalances which contributes to leaky gut. In this instance, insulin resistance causes hyperglycemia where there is too much sugar or glucose in the blood.

Insulin’s role is to bring glucose into the cell, when a person’s cells become resistant to insulin, glucose is unable to enter, leaving excess sugar in the blood.

As discussed earlier, blood sugar imbalance can lead to intestinal permeability or leaky gut.

Estrogen, progesterone and food sensitivities

One of the most common hormone imbalances is excess estrogen and low progesterone. Estrogen can increase histamine levels and vice versa (3). Histamine even plays a role in period pain; as estrogen stimulates the production of prostaglandins which cause period pain; as histamine increases estrogen in turn can worsen period pain (3). On the other hand, progesterone reduces histamine levels.

Histamine is a chemical that is stored in certain cells within our body. Histamine is known for it’s role in allergies, common symptoms of excess levels of histamine can include irregular and painful periods, swelling, hives, headaches, runny nose, asthma and in serious cases anaphylaxis. While we produce histamine naturally in our bodies, it can also be found in foods such as; aged cheese, tinned fish, processed meat such as salami, tomatoes and spinach.

Our body metabolises histamine through two enzymes; diamine oxidase (DAO) and histamine n-methyltransferase (HNMT). Histamine intolerance or sensitivity occurs when the body is unable to process or break down histamine properly. A common reason for histamine intolerance is imbalanced gut bacteria and leaky gut (4).

Thyroid and food sensitivities

The most common imbalance of thyroid hormone is Hashimoto’s disease, which is an auto-immune disease and the most common cause of hypothyroidism. Thyroid hormone imbalance and is linked to food sensitivities. When a person has thyroid imbalance, there is inadequate levels of T3 and T4 thyroid hormones. T3 plays a key role in maintaining the intestinal lining, therefore when there is low levels of T3, it can contribute to intestinal permeability or leaky gut (5). In addition, an inbalance of gut bacteria or dysbiosis is also linked to thyroid autoimmune disease (6).

A common sensitivity in Hashimoto’s disease is gluten sensitivity, so it is important to eliminate gluten from the diet, in addition to establishing optimal thyroid hormones, in particular, T3. Once your thyroid hormones are back in balance it will become a lot easier to address food sensitivities.

Often there is underlying inflammation contributing to thyroid autoimmune disease. Some examples of the cause of underlying inflammation are poor diet, dysbiosis (an imbalanced microbiome) or chronic stress.

Hormones and gut health are areas I specialise in. If you need to support with either of these areas, please reach out. I offer a free 10 minute discovery call, contact me at meastpowell@gmail.com to book a time.

References

1. Campos-Rodríguez, R., Godínez-Victoria, M., Abarca-Rojano, E., Pacheco-Yépez, J., Reyna-Garfias, H., Barbosa-Cabrera, R. E., & Drago-Serrano, M. E. (2013). Stress modulates intestinal secretory immunoglobulin A. Frontiers in integrative neuroscience, 7, 86. https://doi.org/10.3389/fnint.2013.00086

2. Sprague, J. E., & Arbeláez, A. M. (2011). Glucose counterregulatory responses to hypoglycemia. Pediatric endocrinology reviews : PER, 9(1), 463–475.

3. Maintz L, Novak N. (2007). Histamine and histamine intolerance. Am J Clin Nutr. 85(5):1185-96.

4. Schink, M., Konturek, P. C., Tietz, E., Dieterich, W., Pinzer, T. C., Wirtz, S., Neurath, M. F., & Zopf, Y. (2018). Microbial patterns in patients with histamine intolerance. Journal of physiology and pharmacology : an official journal of the Polish Physiological Society, 69(4), 10.26402/jpp.2018.4.09. https://doi.org/10.26402/jpp.2018.4.09

5. Hodin, R. A., Shei, A., Morin, M., & Meng, S. (1996). Thyroid hormone and the gut: selective transcriptional activation of a villus-enterocyte marker. Surgery, 120(2), 138–143. https://doi.org/10.1016/s0039-6060(96)80280-7

6. Lerner, A., Jeremias, P., & Matthias, T. (2017). Gut-thyroid axis and celiac disease. Endocrine connections, 6(4), R52–R58. https://doi.org/10.1530/EC-17-0021