On oxalates, glutamates, autism and DNA

As alluded to in another post last month, I was recently forced to reconsider whether many if not most of my ongoing issues of increased pain, sleep issues and more are related to ongoing issues with oxalates (a topic I covered in a post a couple of years ago at the point I first found out about, and began to tackle them in my diet). Without repeating myself, oxalates are anti-nutrients found in certain plant foods and not all of us are so well equipped to process them in an appropriate manner, leading to storage of oxalate crystals in the body, resulting in a myriad of symptoms and effects including damage to mitochondria, chronic inflammation, immune issues, fibromyalgia and arthritis.


When I first embarked on the process of introducing a low-oxalate diet around that time, I certainly felt some benefit yet still felt niggled by the belief that the low-oxalate diet was not a long-term sustainable option or a well-balanced choice, especially as a vegan. I worked diligently at keeping the highest oxalate foods out of my diet (sweet potato, spinach and almonds especially) but, over the course of the next 2 years, and perhaps almost inevitably given my resistance to the idea, some of these efforts at maintaining a low-oxalate diet lapsed, particularly after I became more complacent towards the end of 2022 following a somewhat better-feeling summer.

It’s amazing how those foods that don’t innately agree with us can start to sneak back into our diet, especially when all we long to do is let go of all the controls and enjoy the same kinds of foods as other people take for granted. Looking back, I see how a mixture of complacency, ignorance about certain newer foods I had recently introduced and genuine forgetfulness conspired to increase my level of oxalates to pretty darned high again in the run up to Christmas, reaching a point where I estimate I was consuming up to 500mg per day (the “safe” amount for humans is considered to be 150 – 200mg, even lower than that for some people who are sensitive). The issue was there, niggling away at me as higher pain levels and other issues, even as I continued to enjoy almost daily dark chocolate, cinnamon sprinkled on my porridge, hearty measures of white potatoes (worse, jacked potatoes…extremely high oxalate), celery most days in my salads, up to 3 pots of daily green tea, a weakness for nut cheeses, almond butter on my toast and so on.

It all came to a head following a pizza in a pub that was made out of cassava flour. My reaction to that (for several days) told me all I needed to know and so I downloaded Sally Norton’s long-awaited book “Toxic Superfoods: How Oxalate Overload is Making You Sick” and skim read it in an evening. The following day, I went through the same book with a fine tooth comb and, since then, I’ve embarked on a much more serious attempt to lower my oxalates than ever I managed before, following Sally’s advice (which is the best I have ever come across as my only sources, prior, were the various forums on the topic but which can be hard to navigate and offer inconsistent advice and various highly contradictory lists of high oxalate foods shared around the internet). Sally’s book was like a lynchpin pulling it all together in a way that felt manageable to me and now, one month in, the effects speak for themselves and are quietly encouraging.

I’m not going to repeat all Sally’s incredibly coherent and well-supported information about what oxalates are and what they can do to a person’s health if they are susceptible. Instead, if you even slightly suspect oxalates may be an issue for you (or if you have a long term chronic pain issue!) I strongly encourage you to read her book for yourself and be prepared to do so with an open mind; one that isn’t vehemently defending the familiar and comfortable, yet probably high oxalate containing, diet that you likely call your own.

To reap the benefits, you have to be prepared to tear things up and start again and that takes courage and determination. To make this feasible, in my case, I decided I had to ditch my vegan diet of the past 5 years, even my veggie diet of the last 10, and have now returned to eating dairy products, eggs and fish (in fact, I had been introducing a few highest quality eggs since last August as a means of introducing a natural source of amino acids). Cheese was no real issue as I have always loved it but fish was no small decision on my part and took some real soul-searching, even a few tears. However, I feel strongly that I am unable to get either the protein or (crucial for oxalate removal) calcium my body needs from a vegan diet when all the best sources of those nutrients come from higher oxalate foods. I have also reached the conclusion, lately, that (possibly due to my autism) I am just one of those people who struggle to translate some of the nutrients in plant sources into the form my body so desperately needs (more on that under the heading DNA testing).

The interesting factor, for me, was that the very first time I ate salmon (a good source of oily fish with high protein content) accompanied by, yes, 3 new potatoes (oxalates contained within…but the objective here isn’t to remove oxalates but to reduce them to a very low level), a hard boiled egg and some sprouted broccoli, I went into a kind of swoon for well over an hour. Having written so recently about oxytocin, the effect reminded me of what that feels like as a sort of “hug” of deep, chemically induced contentment and calm that suddenly comes over me as I lay down my plate. The same thing has happened to me on each subsequent occasion of eating fish and I have since read that not only does oily fish boost oxytocin (see article) but the effect could be something to do with it being a high, therefore much needed, source of omega 3s which my deficient brain seems to lap up thirstily, more on that below, with a resultant boost to all the better feeling neurotransmitters for a while afterwards. On those nights I have had fish, I sleep better, have no stomach gripes at all (so rare for me) and wake feeling uncharacteristically refreshed in a calmer mood and with all cylinders firing. By comparison, on days I go back to a more typical for me plant-based diet (albeit with lower oxalates now) I often feel restless, bloated, acidic, sore or stomach-achy and have higher levels of pain.

Not only do I recommend that you deep-dive Sally’s book for all the most accessible information on oxalates and how to reduce them but I would say that its essential that you take on board, first hand, all her advice about how carefully and slowly you need to do this or risk some very serious repercussions. It can be hard not to rush at the gate of eliminating a food group that you now realise has been causing discomfort and pain but I have had to try to curb my zeal and you must too. Even at a fairly steady rate, I have noticed oxalate crystals coming out of my skin (especially my neck, jaw and collarbone area, also legs and feet) and my urine, had much intensified interstitial pain, rectal soreness and vulvodynia during times of release, episodes of loose teeth, changes in the intensity of my tinnitus, heart palpitations, gritty eyes like they are full of sand and periodic foggy vision, burning mouth plus the need to drink so much more water (often laced with lemon juice, as Sally discusses, for enhanced citric acid to escort oxalates out). Also, a sort of roaming collection of sundry, often bizarre, sometimes pretty unpleasant but thankfully quite brief, symptoms affecting various parts of the body such as random stabbing pains or a day of a particular bone or organ hurting only to abait the next day as though I had imagined it.

My symptoms won’t be your symptoms as the way that accumulated oxalates leave their storage places in tissue and organs are quite unique to each individual and can be troublesome or even painful, for some people, or fairly uneventful for others. I appear to be somewhere in the middle as it sometimes feels intense but not overly prolonged as bouts of “dumping” are punctuated with increasingly longer spells of feeling relief. I’ve been taking calcium citrate with all my meals to help escort oxalates out and, as I keep urging you to do, following Sally’s advice as closely to the letter as possible. The result is, I do believe some of my pain levels are going down, I have had more mobility in my joints, less generalised inflammation, far less IBS or bloating and stomach soreness (in fact, an unfamiliar level of digestive neutrality), enjoyed moments of enhanced cognitive clarity and even levels of vision clarity that normally elude me and many more positives that continue to unfold day after day.

Looking back with the full acceptance that can only come from admitting that this has been a problem for me for the longest time and one I have to (finally) tackle with no more avoidance of the issue, I can see that oxalates have been presenting challenges for me all of my life, although never so out of control as when I began to reduce valuable sources of calcium, such as milk and cheese (which I consumed almost to excess until my mid 20s) because of some dietary fad or supposed health diet. This was especially so once I embarked on all the various anti-inflammatory diets that are fully plant-based in my desperation to heal from fibromyalgia and an assortment of other chronic health issues and pain although, ironically, I now see how I was likely contributing to the problem.

As per so many people in the last decade or so, I plunged head-first into the Medical Medium and celery juicing, almost into raw eating (though that never quite agreed with me) and certainly a diet that read like a wholefood grocers shop. Even when not exactly raw, I have tended to consume as many types of minimally cooked vegetables, seeds, nuts and other wholefood as I can get my hands on in my zealous efforts to “eat clean” and cure inflammation. I truly believed I was doing the best thing for my body, eating a diet that was akin to medicine to get me well again. The tripwire of all these foods is that just so many of them are higher oxalate foods and I no longer had the animal-sourced calcium sources of food in my diet to counteract them (people tout spinach as a high calcium food source, however it contains so many oxalates that its mineral content, including iron, is often rendered useless by the fact these oxalates mop them all up before they are of any use to you – oxalates can badly interfere with mineral absorption) thus my levels of oxalate stored in the body were, likely, increasing year-on year. Like a lobster finding itself in hot water, I hadn’t even noticed, at first, that the temperature was steadily increasing to boiling point from tepid and so, by the end of last year, it was my so-called “normal” state to be in near constant pain with inflamed bursitis in my joints, burning skin, vision issue, tinnitus, interstitial cystitis more often than not, near constant vulva pain, burning feet…you name it, I was putting up with it. Yet, not so very far beneath the surface, as with many people before me, I had also spent years feeling utterly bewildered as to why my health was so poor, my nutrient status so precarious and in constant need of being supplemented, given I was eating such a healthy, organic, home-prepared plant-based diet day in and day out. As her title “toxic superfoods” implies, Sally covers this topic throughly in her book.

Of course, not everyone has this issue with oxalates, in which case by all means eat all those plant foods to your heart’s content and don’t worry about it, but we are not all made the same. The fact of the matter could simply be, I am probably not suited to a full plant based diet and the reason could be genetic. The link between oxalate issues and autism is well known (87% of autistic children were found to be very high in oxalates in one study) to the degree that many parents of autistic children now seek testing for oxalates as standard and subsequently put them onto a low-oxalate diet, with countless anecdotally good results. The same for me, going back two years ago although, its fair to say, I didn’t try my lower oxalate diet for long enough (nor minimise enough of the oxalate sources in my diet!), that time around, to really and consistently enjoy the benefits.

This time, I am in for the long haul and returning to dairy and fish has made my diet feel rounded enough for me to sustain this because I am now back to enjoying my food, probably more than I have for years, partly because the palette suits me far better than a constant array of nut cheeses, juices and spicy Buddha bowls stuffed with pulses, seeds and more varieties of veg than you can shake a celery stick at (at last, I admit I am a greater fan of the simple one protein source plus 2 veg kind of meal; my happy place). Also, because my stomach is feeling soooo much better, my bladder has calmed down, I seldom wake gripping my guts or feeling bloated at 3am and I can tell I am starting to enjoy far better brain chemistry, more consistently, than is generally my baseline. I am even starting to notice less environmental sensitivities, including to EMFs (a sensitivity subgroup that I feel certain is related to stored oxalate levels in the body as oxalates hold electromagnetic charge as well as super-sensitising the first frontier protective layer that is the skin). Its early days but I’m so glad I had the nerve and resilience to embark on this.


Another old friend, I have talked about glutamates many times before and, as with oxalates, I strongly suspect my issue with these is related to my autism as there is a strong correlation. Symptoms of high glutamates include anxiety, depression, restlessness, inability to concentrate, overactive thoughts stuck on loop, headaches, insomnia, fatigue, and increased sensitivity to pain. The following source mentions a prior study that “reported significantly higher blood and brain glutamate levels in children with autistic disorders”, also that “accumulating evidence suggests that overstimulation of glutamate receptors, impaired mitochondrial functions, and oxidative stress are interconnected events that lead to oxidative neuronal injury in patients with autism”. It continues:

“Children with ASD exhibit low plasma and cellular glutathione (an endogenous antioxidant) levels and reduced capacity of glutathione reserve; therefore, they are highly susceptible to oxidative stress. It has been documented that oxidative stress and redox imbalance are crucial components of ASD pathophysiology. Glutamate-mediated excitotoxicity has been reported as one of the essential contributing factors in developing oxidative stress in ASD [80]. Glutamic acid decarboxylase (GAD), an enzyme that catalyzes the transformation of glutamate to gamma-aminobutyric acid (GABA), glutamine synthase, and GABA receptors, are susceptible to oxidative injuries. The reduced levels of GAD in the brain promote excitotoxicity by decreasing GABA and increasing glutamate levels”. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9135628/).

This is the long way of saying, excitoxicity can become your norm if you struggle with glutamates, leading to increased anxiety, chronic fatigue, enhanced pain but also much increased sensitivity to environmental triggers, as I can attest to. Adding high glutamate foods into the diet can detrimentally tip the balance towards a chronic glutamate issue, something I felt I had reached a few years back when pain levels and reactivity to environmental factors became extreme. For years since then, I have managed to keep these effects somewhat in check through near total avoidance, not only of “MSG” but, of all the various so-called flavour enhancers, “natural flavourings” (as they are so euphemistically labeled…do you know there are countless other patented versions of MSG out there and they only have to be labelled MSG if they are more than 99% pure MSG!), modified starch, yeast extract and so on; processed foods are riddled with these ingredients. I have also avoided miso and soy sauce for years. However, I had become a little careless lately (mostly around vegan substitute foods such as the new kind of “meaty” burgers and sausages, some vegan cheeses containing flavourings, etc) and also, here’s the catch, some of the foods I have now reintroduced in the context of my low-oxalate diet such as cheese and milk, which have higher content of free-glutamates in them, are something I have to keep my eye on. Other higher glutamate foods include mushrooms, tomatoes, shellfish, eggs.

Whilst this crossover with glutamates isn’t going to persuade me to ditch my newly reintroduced dairy (such a nutritious source of calcium without the need for high oxalate plants), it does mean I have to be mindful of what kinds of dairy I choose to consume: Parmesan, for instance (which you can now get with vegetarian rennet) is extremely high in glutamates so I will be giving it a miss, as is Roquefort and emmental. Cheddar is considered OK and I have a penchant for goat and sheep cheese as they are easier to digest and I suspect these are a fairly safe bet. Mozzerella is extremely low. As ever, it’s a case of, not so much of elimination but, knowing about potential glutamate levels and keeping these kinds of food intermittent and in proportion.

There are also ways of countering high glutamates and they include taurine (an amino acid which excels at mitigating toxic levels of glutamate) and GABA (which is the opposite factor to glutamate in the brain), both of which I already supplement, also ensuring you get good levels of magnesium, also of omega 3s as I already mentioned is high in fish (more on that below). Vitamin B6 is an essential cofactor in converting glutamate into GABA and is recommend at a higher dose for dealing with oxalate detox as well (see Sally Norton’s book) so that’s a useful cross-over. Taking NAC supplements has helped me enormously over the last year and may be to do with increasing levels of glutathione to counter higher glutamate levels. From one study:

“NAC reversed the anxiety-like behavior and oxidative damage observed in stressed animals. Additional studies are needed to investigate the effects of this agent on glutamatergic modulation and inflammatory markers related to stress.” N-Acetylcysteine Reverses Anxiety and Oxidative Damage Induced by Unpredictable Chronic Stress in Zebrafish – PubMed

DNA testing as a useful insight

Which brings me neatly to my next topic, that being the very useful tool that is DNA testing. As a video I was watching reminded me, the health results that sometimes come along with the heritage DNA tests that are so widely available these days can be useful for flagging up genetic shortcomings when it comes to digesting certain food groups or nutrients.

In my case, I had my results back on one particular test last year and it flagged up results that are even more meaningful to me now, in the light of my decision to cease a fully plant based diet.

In my case, it turns out I have difficulties converting beta carotene from plants into useable vitamin A (“autistic children have the highest deficiency of vitamin A compared to other nutrients”, see article so this could be an issue for me). My results also flag up a potential shortfall when it comes to efficiently metabolising omega 3s something (which has been linked to autism, see article). They suggest I may also be at a disadvantage when it comes to processing vitamin B12 efficiently (interestingly I’ve read “vitamin B12 is often touted as the single most effective biomedical therapy for autism issues, see article). What’s more, they also indicate I may have issues with breaking down carbohydrates and sugars, affecting blood glucose regulation (this is consistent with my experiences yet foods like potato or rice proved so difficult to avoid on a plant based diet especially given I had tried, but failed, to go keto given the reliance on foods I find highly triggering such as nuts, seeds and other foods I now know to be high oxalate).

All of these results seem to suggest that a fully plant-based diet may not be the right choice for me and that this is coded into my genes. B12 is absent in plants and needs to be supplemented diligently if you are plant based but I somehow knew I was always running low, however hard I tried to supplement. The fact is, this may be much more easily obtained from foods such as meat, fish, and egg (I will settle with the last two of those). In its most useable form (if I have issues translating beta carotene), Vitamin A comes from eggs, salmon, sardines and tuna and this should get around any issues I have converting beta carotene. The good news is that, in the avoidance of oxalates, I am now using alternatives such as swede or celeriac instead of potato and these are half the cabs of potato. Even better news from my DNA results is that I don’t seems to have a genetic issue with lactose (something I had assumed I did, though I had never had it tested) and am unlikely to be celiac. My pet theory is that my real issue with gluten containing foods is their link to higher glutamates, which is consistent with everything I have shared above, resulting in gluten sensitivity (really, glutamate sensitivity) which still makes it pertinent to avoid gluten as far as possible but perhaps not in quite the same, cross-contaminant avoiding, way as I have done to date.

The reason I am sharing all this is that, whilst my DNA results are (of course) specific to me and cannot be taken as gospel at such a broad brushstroke level of analysis as provided in a heritage genes test (besides, genetic coding can lean you towards a trait but is not the whole of the story as epigenetic factors also come into play), I have found it tremendously useful to gain some clarity on my genetic leanings, in light of recent experiences and making new food choices. It feels incredibly validating to have my pet theories about B12 and omega 3s, even vitamin A (which I have tried, and failed, to supplement in the past) confirmed so that I can formulate a strategy for increasing food sources of these essential nutrients, going forwards.

The autism part of the jigsaw, which was missing the first time I considered glutamates so many years ago, has also been a huge part of the picture as it does seem that autism lends itself towards poor handling of oxalates, glutamates and some other dietary factors including omega 3s. As above, I do feel that, since my omega 3 status improved with the addition of so much oily fish (salmon and trout are my regulars) my brain has felt, somehow, clearer, less clunky and far less prone to burnout or brain fog (unless I am undergoing a period of oxalate dumping symptoms in which case all bets are off for a day or two), in fact there is almost a visceral sensation of brain expansion and enhanced calmness that comes over me when I have enjoyed a hearty fish dish and I find myself looking forward to the sensation after my next fishy meal. When the body speaks to you directly like this, it can be extremely compelling and is far more validating than anybody else’s opinions about what you should or should not be eating, however convincing they may try to be!

We are not all made the same and some of us are quirkier (or glitchier!) than others; it takes getting to know yourself and diligently doing the detective work to get somewhere, as I finally am at the ripe old age of 54. Late as this might be, I am quietly optimistic that I am getting onto the right path at last and that all this self-enquiry and effort is starting to pay off after years of feeling stuck or being thrown back into the mire when some food type trips me up. If any of this sounds like you, I encourage you to do your own investigations and experiment to see if you can iron out any dietary sticking points that may have been, inadvertently affecting your health, your sensitivities and even your mental and emotional wellbeing…perhaps for years.


This website is not designed to, and should not be construed to, provide medical advice, professional diagnosis, opinion or treatment to you or any other individual, and is not intended as a substitute for medical or professional care and treatment. Please see medical advice from a qualified professional before changing your diet or supplement regime.

2 thoughts on “On oxalates, glutamates, autism and DNA

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