Plant Anti Nutrients: If you struggle with autoimmunity it can be difficult to navigate the world of nutrition. There are so many different approaches to eating and healing protocols created by nutrition experts. I have run the gamut of dietary approaches, going from paleo to keto, to strict AIP (autoimmune protocol) in hopes of healing my autoimmune thyroid and Sjogren’s. Over the years, I have adhered to a strict gluten-free diet, although currently, I am consuming gluten-free grains.

Over the past couple of years, I have been intrigued by the carnivore diet, and have been reading and researching the benefits for those of us who struggle with thyroid health and autoimmunity. I wanted to better understand the reason why “harmless” and touted as healthy vegetables can impact thyroid health, as I am about to embark on a carnivore experiment. I wanted to share with you information I found valuable on the role of plant anti-nutrients on autoimmunity, especially pertaining to thyroid health.

Anti-nutrients found in plants.

Vegetables and grains don’t really want to get eaten by bugs. Who could blame them? So they have built-in mechanisms to protect them. These anti-nutrients found in vegetables and grains have some benefits, but can also impact gut health, especially in the autoimmune population. Here are some of the anti-nutrients found in plants and how they can impact human health (focusing on thyroid health). Many of these anti-nutrients can especially impact those of us who struggle with autoimmunity.

Plant Polyphenols and Flavonoids

We often hear about how healthy polyphenols and Flavonoids are—and there are many health benefits, such as being antioxidants fighting off free radicals that cause oxidative stress. Polyphenols are found in dark chocolate, berries, beans, nuts, and vegetables. Flavonoids are found in fruits, vegetables, grains, bark, roots, stems, flowers, tea, and wine. However, plant polyphenols and flavonoids can also impact gut health and thyroid health.

Researchers studied a number of polyphenols and flavonoids, discovering they inhibited thyroid peroxidase (TPO). Inhibited TPO levels decrease thyroid hormone levels, increasing TSH, and causing goiters. Flavonoids could also affect the availability of thyroid hormones to target tissues, by inhibiting deiodinase activity or displacing T4 from transthyretin. Thus, flavonoids have been shown to interfere with thyroid hormone synthesis and availability.

Phytic Acid (Phytate)

Phytic acid is found in plants—particular needs and seeds. It’s considered to be an anti-nutrients such as iron, zinc, and calcium from being absorbed into the body. Many of these minerals are imperative for thyroid function. This is why many Autoimmune protocol diets tend to avoid nuts and seeds. Sprouting and fermenting can help break down the phytic acid so the body can get more nutrients. However, eating raw nuts can really inhibit nutrients from getting to the cells, thus impacting thyroid health.

Tannins

Plant tannins are a major group of antioxidant polyphenols found in food, wine, and tea. Although they possess multiple health benefits,  Tannins can also impair the digestion ad bioavailability of a variety of nutrients. Tannins bind and shrink proteins. Tannin-protein can inactivate digestive enzymes and therefore impacting the ability to fully digest nutrients from proteins.

Lectins

Lectins are found in wheat, beans, quinoa, peas, etc. They are proteins or glycoproteins of non-immune origin. Lectins have a variety of roles. Lectins bypass our immune system and can damage the lining of the small intestines, contributing to increased gut permeability (AKA “leaky gut syndrome”). Lectins are known to stimulate insulin responses in the cells and contribute to autoimmunity. Although we here that “whole grains” are needed for our health, lectins are primarily found in the hull. So if you’re sensitive to them, white rice is actually a better option. Cooking plants can help lower the lectin amount.

Goitrogens

A goiter is a growth or enlargement of the thyroid, typically caused by stress, environmental factors, and autoimmunity. Goitrogenic foods interfere with iodine absorption, thus impacting thyroid function. Some goitrogenic foods include broccoli, cabbage, cauliflower, Brussels sprouts, and kale. These cruciferous vegetables impact thyroid hormones and can lead to goiters.

Plant Oxalates

Cruciferous vegetables also contain large amounts of oxalates or insoluble salts. These salts cannot be processed by the body and can accumulate and form kidney stones. Oxalates are handled well by many people. However, some people are sensitive to them and cannot even have a small amount without experiencing symptoms.

 

Ways to Reduce Anti-Nutrients in Plants?

If you struggle with digestive health issues, thyroid problems, leaky gut, and autoimmunity, there are ways to reduce antinutrients from plants. However, some people find they have to remove certain greens/vegetables/fruits from their diet altogether if really struggling with a particular antinutrient, such as gluten or oxalates.  When our ancestors started consuming grains, they knew how to properly prepare them in order to get adequate nutrients from them, and for ease with digestion. Nowadays, most people do not properly prepare grains, and this is one big reason for digestive health issues and immune disorders. Some ways to consume grains and reduce your exposure to anti-nutrients are through soaking, fermentation, and sprouting (more on these methods in upcoming pieces).

References:

Habza-Kowalska, Ewa et al. “Thyroid Peroxidase Activity is Inhibited by Phenolic Compounds-Impact of Interaction.” Molecules (Basel, Switzerland) vol. 24,15 2766. 30 Jul. 2019, doi:10.3390/molecules24152766

Kimura S., Kotani T., McBride O.W., Umeki K., Hirai K., Nakayama T., Ohtaki S. Human thyroid peroxidase: Complete cDNA and protein sequence, chromosome mapping, and identification of two alternately spliced mRNAs. Proc. Natl. Acad. Sci. USA. 1987;84:5555–5559. doi: 10.1073/pnas.84.16.5555. – DOI – PMC – PubMed

de Souza Dos Santos MC, Gonçalves CF, Vaisman M, Ferreira AC, de Carvalho DP. Impact of flavonoids on thyroid function. Food Chem Toxicol. 2011;49(10):2495-2502. doi:10.1016/j.fct.2011.06.074

Köhrle J, Spanka M, Irmscher K, Hesch RD. Flavonoid effects on transport, metabolism and action of thyroid hormones. Prog Clin Biol Res. 1988;280:323-340.

Lerner, Aaron et al. “Gut-thyroid axis and celiac disease.” Endocrine connections vol. 6,4 (2017): R52-R58. doi:10.1530/EC-17-0021

Mohamed TM, Salama AF, El Nimr TM, El Gamal DM. Effects of phytate on thyroid gland of rats intoxicated with cadmium. Toxicol Ind Health. 2015;31(12):1258-1268. doi:10.1177/0748233713485887

Schlemmer U, Frølich W, Prieto RM, Grases F. Phytate in foods and significance for humans: food sources, intake, processing, bioavailability, protective role and analysis. Mol Nutr Food Res. 2009;53 Suppl 2:S330-S375. doi:10.1002/mnfr.200900099

Chandra AK, De N, Choudhury SR. Effect of different doses of un-fractionated green and black tea extracts on thyroid physiology. Hum Exp Toxicol. 2011;30(8):884-896. doi:10.1177/0960327110382563

Hendek Ertop M, Bektaş M. Enhancement of bioavailable micronutrients and reduction of antinutrients in foods with some processes. Food Heal 2018; 4(3): 159-5.
[http://dx.doi.org/10.3153/FH18016]

Salunkhe DK, Chavan JK, Kadam SS. Dietary tannins: Consequences and remedies 1990; 150-73.

Karpova IS. Specific interactions between lectins and red blood cells of Chornobyl cleanup workers as indicator of some late radiation effects. Exp Oncol 2016; 38(4): 261-6.
[http://dx.doi.org/10.31768/2312-8852.2016.38(4):261-266] [PMID: 28230832]

Fahmi N, Sharma N, Pandey A, et al. Interactions of lectins in the red blood cells of oral squamous cell carcinoma patients: A comparative study. Int J Curr Adv Res 2017; 6(7): 4753-7.

Peumans WJ, Van Damme EJ, Barre A, Rougé P. Classification of plant lectins in families of structurally and evolutionary related proteins. Adv Exp Med Biol 2001; 491: 27-54.
[http://dx.doi.org/10.1007/978-1-4615-1267-7_3] [PMID: 14533788]

Losvik A, Beste L, Mehrabi S, Jonsson L. The protease inhibitor CI2c gene induced by bird cherry-oat aphid in barley inhibits green peach aphid fecundity in transgenic arabidopsis. Int J Mol Sci 2017; 18(6): 1317.
[http://dx.doi.org/10.3390/ijms18061317] [PMID: 28632160]

Vijayalakshmi A, Kiran Kumar Y. Evaluation of goitrogenic and antithyroidal effect of the fern Adiantum capillus-veneris. Brazilian J Pharmacogn 2013; 23: 802-0.
[http://dx.doi.org/10.1590/S0102-695X2013000500013]

Latté KP, Appel KE, Lampen A. Health benefits and possible risks of broccoli – an overview. Food Chem Toxicol 2011; 49(12): 3287-309.
[http://dx.doi.org/10.1016/j.fct.2011.08.019] [PMID: 21906651]

Abdul-Aziz A. efficacy of the cruciferous vegetable on the thyroid gland and the gonads in rabbits. Adv Anim Vet Sci 2015; 3(3): 183.
[http://dx.doi.org/10.14737/journal.aavs/2015/3.3.183.191]

Akwaowo EU, Ndon BA, Etuk EU. Minerals and antinutrients in fluted pumpkin (Telfairia occidentalis Hook f.). Food Chem 2000; 70(2): 235-40.
[http://dx.doi.org/10.1016/S0308-8146(99)00207-1]