Veganism and Hashimotos Disease

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Research Advisory Committee member, Dr Caroline Gorden asks “Do you think Seren got ill because she’s vegan?”

OK, so no one has directly asked me ‘Do you think Seren got ill because she’s vegan?’ But they might as well have done. I consider the following questions that people have asked me to be the same:

‘Has anyone asked you if you think Seren got ill because you’re all vegan?’

‘Do you get many people blaming the vegan thing?’

‘Did you know that there are some really common mistakes that vegans make in relation to their health?’

‘I know someone who cured their autoimmune disease on a purely carnivore diet.’

And there are other judgements that slip through during conversations – interestingly, it’s sometimes expressed by children of friends and family:

‘Oh well, that’s good she can have soy because you know, she can’t have gluten and the other things’ ‘The other things’ presumably meaning meat and dairy.

I knew when Seren was diagnosed that I would get these kinds of questions. After all, being vegan is going against the status quo. Massively. We only account for around 1.2 percent of the population in the UK [1] and that’s after an enormous increase in veganism over the last eight years or so. As a family, we adopted a vegan diet almost six years ago and we did so for all the reasons that anyone who can adopt a vegan diet, should. Don’t worry, I’m not going to list all the reasons why transitioning to a vegan diet is the optimal thing to do (e.g. from an ethical point of view, your health, and the environment) because I would literally be here for days. I list the reasons here but suffice to say, first, a recent Global Sensitivity Analysis indicates that animal agriculture is responsible for 87 percent of GHG emissions [2].  Second, there’s the fact that 85 percent of animals reared for human consumption live in factory farms, the conditions of which must constitute one of the worst crimes of the 21st Century [3]. Again, I could tell you all the gory facts and details about what happens once your factory farmed bacon or sausage are given birth to – how their teeth are clipped, and tails docked to prevent the inevitable cannibalism of each other because of sheer boredom and frustration (in an interview I talk about how UK legislation allows for these practices here). Or of course, you could watch Hogwood: A Modern Horror Story on Netflix about a pig farm in the UK that supplied major supermarkets. And no, these conditions aren’t an exception to factory farming – look no further than footage filmed by the likes of Viva! and other activists like Ed Winters and Joey Carbstrong – they do extremely important work on educating us by uncovering the reality of how we treat animals in this country, exposing us not as a nation of animal lovers but instead, a nation of animal abusers. Third, a great benefit of adopting a plant-based diet concerns human health. Now this is the primary focus of this blog since I need to answer the question about whether I think Seren’s plant-based diet had anything to do with the onset of her Hashimoto’s. To do that, we need to look at what the known causes and triggers of this disease are, but first, what does the most up-to-date research tell us about plant-based eating and human health?

The available data underline the harms meat and dairy can have on human health. Dr Shireen Kassam and Dr Zahra Kassam are both cancer doctors here in the UK and Canada and wrote the book Eating Plant-Based. They reviewed all the latest research on the benefits of a plant-based diet and cite papers indicating that a plant-based diet can reduce the risk of heart disease by 25 percent [4],[5],[6], type 2 diabetes by up to 50 percent [7],[8],[9] and high blood pressure by 60 percent [10] and can support healthy blood cholesterol levels [11]. Whether you have other healthy lifestyle habits or not, a plant-based diet has shown its ability to arrest coronary heart disease [12],[13],[14] and can even halt the progression of early-stage prostate cancer [15]. Importantly, the British Dietetic Association endorses the view that a well-planned vegan diet can support healthy living in people of all ages [16].

One of the common most arguments against veganism is that ‘we are carnivores’ and therefore designed to eat meat and so it is somehow essential to maintaining health. Notwithstanding the absence of our sharp, carnivorous teeth and an instinct to chase and kill birds or rabbits or whatever, we are in fact, omnivores meaning we can eat both animal products and plants [17]. But animal products are in no way essential to our diet because except for B12, ‘there are no nutrients within animal-derived food that cannot be obtained from whole plant foods’[18]. Indeed, without plant-foods, our health would suffer because they contain essential vitamins and minerals. Additionally, 70 percent of the global population are lactose intolerant for a simple reason: we lack the lactase enzyme once milk becomes unnecessary to our diet [19]. A genetic mutation allows the rest of us to digest lactose because we started the cultural practice of dairying around 10,000 years ago. Cow’s milk is a biological fluid designed to support a calf’s growth; it’s not designed for your growth. In fact, no other species drinks milk once it’s no longer required in their diet (past age 3 or 4). But here we are drinking it until old age. Think about how weird that is. Yet we have been led to believe that dairy is synonymous with bone health despite there being no evidence to support this argument [20]. In fact, Kassam and Kassam point to the research that demonstrates countries where people consume the most dairy also have the highest rates of bone fractures [21]. Let’s not forget that cows get their calcium from plant sources. You can obtain calcium from nuts and seeds p [22], and the Vegan Society recommend that calcium also be obtained from fortified plant milk and calcium set tofu that provide significant contributions to meeting your calcium needs.

I have come up against medical professionals who baulk when I tell them we’re vegan but there is a simple explanation for this. Kassam and Kassam (2022) argue that doctors will unlikely recommend a plant-based diet because they generally receive very little, if any, education on nutrition during their time at medical school [23]. In the mainstream of course, meat and dairy are still constructed as key staples in a healthy diet. In June, Seren was hospitalised with a swollen knee. A senior doctor asked me what Seren eats since she is sensitive to so many foods. He couldn’t believe it when I said she doesn’t eat eggs and he even asked me what tofu is. Eggs – traditionally thought of as a very natural (really? See here) and healthy food, most people aren’t aware of the research on TMA (trimethylamine), which is a compound produced after eating eggs and once absorbed into the blood is converted into trimethylamine oxide (TMAO). Kassam and Kassam highlight the research that shows this substance has been ‘intimately’ linked with the development of atherosclerosis, heart failure, type 2 diabetes and kidney failure [24],[25],[26],[27]. But I am pretty sure if I had told the doctor that Seren eats an egg sandwich for lunch every day, it would have been a satisfactory answer. Or if I had said she has a ham sandwich, it would have been met with equal satisfaction. Never mind the fact that the World Health Organisation declared processed meat as a Group 1 carcinogen meaning that there is convincing evidence that it causes cancer, and in particular, the IARC Working Group concluded that eating process meat causes colorectal cancer. Additionally, a systematic review and meta-analysis of existing studies demonstrated an associated between high processed meat consumption and an increased breast cancer risk [28]. Red and processed meat may also be associated with an increased risk in prostate cancer (see Nouri-Majd et al’s. (2022) systematic review and meta-analysis) [29], [30]. Astonishingly, epidemiological studies demonstrate a 46-88 percent reduced risk of colorectal cancer for those adopting a plant-based diet [31]. Thus, the current research picture on this issue is clear – plant-based eating is a far from a fad. It is here to stay and one day future generations will look at medical professionals eating meat the way we look upon them now if we see them smoking.

Causes of hypothyroidism

I wrote in my first blog that hypothyroidism (underactive thyroid) may have different causes – Hashimoto’s (an autoimmune condition) being the most common cause. According to the British Thyroid Foundation, another cause is lack of iodine (which helps to make thyroid hormones) and although some online resources suggest this is unusual in the UK (and is more common in developing countries where there may be a depletion of iodine in the diet), it should be noted that that the British Dietetic Association suggests that there is an increasing concern that this is no longer the case – note that there isn’t a stipulation for salt to be iodised here in the UK as it is in other countries). Notwithstanding the fact that Seren’s cause is autoimmune and not iodine deficiency, some plant-based milks are now fortified with iodine and my children have always been given iodised salt. 

There’s this misconception that children on a vegan diet will be devoid of a range and variety of foods. I often hear parents say, ‘I want my child to eat everything’, presumably to avoid fussiness and receive a wide range of nutrients. But where so much junk food contains animal products, these can become very appealing over healthy foods whereas vegan children will likely start looking for more healthy treats available to them. My four-year-old son loves pecan nuts and eats hummus every day. All three of my children eat chickpea pancakes where I load them with flaxseeds, chia seeds and hemp seeds. We have Nomato Sauce (like tomato sauce but without the tomatoes), which is loaded with nutrients. Seren’s not quite 11 and yet her culinary skills are genuinely impressive. She knows how to cook, and she knows why she’s adding things like nutritional yeast to her meal, that she needs vitamin A and D to keep her hair healthy and full of life, and that she needs a Brazil nut each day for its selenium. Yes, she is thin and small for her age, however, an x-ray showed that Hashimoto’s significantly stunted her bone growth, and she generally can’t tolerate fatty foods. But I would put money on it that she consumes a more nutrient dense diet that most other adults and children she knows.

Dietary triggers for Hashimoto’s

Spoiler alert: a vegan diet doesn’t appear on the list of known triggers for this disease. There are lots of debates about dietary triggers and some named ones include casein (a protein found in dairy milk), albumin (found in many animal products), grains, gluten, and glyphosate rich foods [32] (the last I’m particularly interested in because it is used in herbicides and has sparked a lot of controversy and calls for a ban – it’s another blog in itself). Lectins also received bad press when Dr Steven Gundry argued it is behind many chronic diseases, however his book isn’t supported by scientific evidence [33]. Lectins are often associated with beans and wholegrains, but they are also found in dairy, eggs, seafood and yeast. Importantly, they are only found in high amounts in raw beans and whole grains. However, as Kassam and Kassam argue, no one eats raw beans and lectins in whole-grains and beans are inactivated within 15 minutes of cooking [34]. I know that Seren can’t tolerate gluten but that would very much fit with the research to date on the role of gluten in Hashimoto’s. Such was the strong reaction that I thought removing it would see a return to health and although symptoms certainly improved, she was still experiencing these periods of unpleasant symptoms (mainly acute nausea). As Kassam and Kassam argue, it’s too good to be true to assume that one nutrient or food causes all the said health problem. We also know from Seren’s food sensitivity test that rice, potato and egg are problematic for her. So, we needed to start looking beyond dietary triggers, which is why we looked at pathogens. As well as antibodies for the black mould, stachybotrus chartarum, there was also evidence of candida albicans. Lifestyle factors also need to be considered although they are limited for Seren because clearly a sedentary lifestyle, insomnia, smoking, alcohol and drug use are not relevant. Finally, we need to look at chemicals. Again, that’s for another blog.

Upstanders versus Bystanders

The most confronting thing for me is not that I get asked these questions about our diet and what link, if any, there is to Seren’s autoimmune disease. Afterall, those questions most likely have genuine intentions. The confronting thing for me is that I whole-heartedly assumed that once people learned about the horrors of factory farming and the damage animal products have on the environment and human health, they would immediately stop paying into such an abusive and cruel system. I was mistaken. People who I respect continue to buy into a system that is simply flat out wrong. It’s a myth that plant foods are more expensive – at least the unprocessed stuff. Also, the meat alternatives are catching up in terms of price parity (and incidentally that’s when we will see change since research tends to show that food choices are strongly motivated by price [35]). However, one of the key reasons for continuing to buy into such an appalling system is speciesism – the belief that one species is more important than another. So conditioned and entrenched are these beliefs within us that people rarely see the dissonance as they love and care for their pet dog while at the same time, munching on their bacon sandwich. The bacon that was once a baby pig and probably more intelligent than their pet dog and yet lived a life not worth living and died a death no one would put their dog through. And even when they do become aware of the nature of factory farming, humans remain prepared to look the other way. In Psychology, this is referred to as the ‘bystander effect’. The research on this area typically focuses on scenarios where members of the public will walk past someone who is being attacked or hurt in some way [36]. Maybe people fail to react in such situations in the hope that someone else will. And when they don’t, this reassures us that we are somehow justified in our inaction. We also don’t want to be an outlier. As Bala (2017) neatly puts it, ‘Nobody wants to deal with issues, precisely because they are issues. They are difficult to confront, and often turning the blind eye is not only easier, but a part of self-preservation. Not many people can stomach seeing the world as it is…[37]

It’s this theory that may help us to understand why there’s so much intolerance for veganism and why I get questioned so often. Those who make a stand (upstanders) are typically like that in other areas of life too. Being an upstander often means saying something when you see something that’s not right. Upstanders don’t grin and bear it and pretend they don’t see. They say something or do something. Upstanders will find themselves in many difficult situations in which there has been some kind of injustice – big or small/intentional or unintentional. By virtue of upstanders being in the minority, it always equals going up against several bystanders. Now the unfortunate news is that bystanders occupy most of the social space – the Sociologist Donald Black referred to this as the social geometry [38] – where people stand in relation to one another may dictate the outcome of the dispute. Because there are more bystanders in any given situation, they are more powerful – the sheer number of them means there’s no shortage of reassurances that their ‘bad act’ wasn’t bad at all. Instead, they will affirm the bad act was completely justified and it is in fact the upstander who has done wrong. In Criminology, we call this ‘condemning the condemner’ – bad acts are ‘neutralised’ [39] by finding ways in which the condemner is somehow wrong and thereby constructed as the villain in the story e.g., the upstander may be accused of reacting inappropriately: ‘You shouldn’t have dealt with it like that’. The truth is, whichever reaction style is chosen, it will be deemed incorrect and once the upstander has been painted that way, everything they say and do will forever more be perceived through the lens especially chosen for them. We only need to look at the upstanding of Harry and Meghan to see an example of condemning the condemner in action. Even the ones who admire what the upstander is doing will, unfortunately, remain completely still and silent because being a bystander is much better than the alternative – rejection of the social group. So, if the bystander effect can be that powerful just in minor (or sometimes quite major) social disputes, it sure as heck is going to wield its power when it comes to ignoring and pretending not to see the extent of the harm animal agriculture is doing. Thus, the condemners of it will surely be condemned.

In conclusion then, the argument that a vegan diet could have caused Seren’s Hashimoto’s disease is unlikely. Unfortunately, despite ensuring Seren received a nutrient abundant diet, she still became ill. Almost a year on, I have been able to identify some patterns to Seren’s off and on wellness and as I have always suspected, the conventional healthcare system overlooks the autoimmune component of Hashimoto’s. For a long time, I have wondered if Seren’s symptoms relate to another separate and new condition. By finding the right experts in this field, I am learning that most likely, it is all autoimmune related and she is a thyroid patient who reflects perfectly Dr Kharrazian’s book title 'Why do I still have thyroid symptoms? When my lab tests are normal?’

Finally, am I depriving my children since it’s my choice for them to be vegan, not theirs? Yes, it’s my choice but it also happens to be an extremely informed one. Until my children are adults and know and understand what kind of system is being paid into along with the consequences of that system, I will make decisions about what goes on the menu. In the meantime, I’ll keep educating them and hope they make the right choice when they’re old enough.

Dedicated to the greatest upstander I know – Cara Langford Watts. Your ‘difference’ is between you and the bystanders who make up the majority. In every battle you have, never forget that.

This article was reposted from the author's personal blog with permission. You can access the original article here.

The views expressed by our Research News contributors are not necessarily the views of The Vegan Society.


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[11] Bradbury, K. E., Crowe, F. L., Appleby, P. N., Schmidt, J. A., Travis, R. C. and Key, T. J. (2014) ‘Serum concentrations of cholesterol, apolipoprotein A-I and apolipoprotein B in a total of 1694 meat-eaters, fish-eaters, vegetarians and vegans’, Eur J Clin Nutr. 68(2):178-83.

[12] Ornish, D., Scherwitz, L. W., Billings, J. H., Brown, S. E., Gould, K. L., Merritt, T. A., Sparler, S., Armstrong, W. T., Ports, T. A., Kirkeeide, R. L., Hogeboom, C. and Brand, R. J. (1998) ‘Intensive lifestyle changes for reversal of coronary heart disease’, JAMA. 280(23): 2001-7.

[13] Esselstyn, C. B., Gendy, G, Doyle, J., Golubic, M. and Roizen, M. F. (2014) ‘A way to reverse CAD?’ The Journal of Family Practice, 63(7): 356-364b.

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[16] British Dietetic Association (2022) ‘British Dietetic Association confirms well-planned vegan diets can support healthy living in people of all ages’, Available from: British Dietetic Association confirms well-planned vegan diets can support healthy living in people of all ages | British Dietetic Association (BDA)

[17] Kassam, S. and Kassam, Z. (2022) Eating Plant Based. Scientific Answers to your Nutrition Questions, London: Hammersmith Health Books.

[18] Kassam, S. and Kassam, Z. (2022) Eating Plant Based. Scientific Answers to your Nutrition Questions, London: Hammersmith Health Books (p. 9).

[19] Kassam, S. and Kassam, Z. (2022) Eating Plant Based. Scientific Answers to your Nutrition Questions, London: Hammersmith Health Books.

[20] Gorden, C. (2019) ‘The Expert Series 9: A Criminological Exploration of the UK Dairy Industry’, The Vegan Society. Available from: The Expert Series (9): A Criminological Exploration of the UK Dairy Industry | The Vegan Society

[21] Michaëlsson, K., Wolk, A., Langenskiöld, S., Basu, S., Warensjö Lemming, E., Melhus, H. and Byberg, L. (2014) ‘Milk intake and risk of mortality and fractures in women and men: cohort studies’, British Medical Journal. 349:g6015.

[22] Kassam, S. and Kassam, Z. (2022) Eating Plant Based. Scientific Answers to your Nutrition Questions, London: Hammersmith Health Books.

[23] Crowley, J., Ball, L. and Hiddink, G. J. (2019) ‘Nutrition in medical education: a systematic review: a systematic review’, Lancet Planet Health, 3(9): e379-e389.

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[25] Missailidis, C. et al. (2016) ‘Serum trimethylamine-N-Oxide is strongly related to renal function and predicts outcome in chronic kidney disease’, PLOS.

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[30] The World Health Organization (2015) ‘Cancer: Carcinogenicity of the consumption of red meat and processed meat’. Available from: Cancer: Carcinogenicity of the consumption of red meat and processed meat (who.int)

[31] Rose, S. and Strombom. A. (2019) ‘Colorectal Cancer Prevention with a Plant-Based Diet’, Cancer Therapy and Oncology International Journal, 15(2): 555906.

[32] Kharrazian, D. (2022) ‘Part 1 – Essential Concepts of Hashimoto’s’, Hashimoto’s: Solving the Puzzle, online programme. Available from: Hashimoto’s: Solving the Puzzle (drknews.com)

[33] Kassam, S. and Kassam, Z. (2022) Eating Plant Based. Scientific Answers to your Nutrition Questions, London: Hammersmith Health Books.

[34] Luo, Y. W. and Xie, W. H. (2013) ‘ Effect of different processing methods on certain antinutritional factors and protein digestibility in green and white faba bean’, CyTA Journal of Food, 11(1):43-49.

[35] See for example, Steenhuis, I., Waterlander, W. and De Mul, A. (2011) ‘Consumer food choices: The role of price and pricing strategies’, Public Health Nutrition, 14(12): 2220-2226.

[36]See for example, Darley, J. M. and Latane, B. (1968) ‘Bystander intervention in emergencies: Diffusion of responsibility’, Journal of Personality and Social Psychology, 8(4, Pt.1), 377–383.

[37] Bala, H. (2017) ‘Why you shouldn’t look the other way: one big reason to stand up for yourself and others’, The Huffington Post, 6th December. Available from: Why You Shouldn’t Look the Other Way: One Big Reason to Stand Up for Yourself and Others | HuffPost Life

[38] Black, D. (1976) The Behavior of Law, New York: Academic Press.

[39] Sykes, G. and Matza, D. (1957) ‘Techniques of neutralization: a theory of delinquency’, American Sociological Review, 22(6): 664-70.

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