UPDATE:  Excellent posts here & here from Emily Deans regarding IBS, Fructose, Depression, and Zinc in Women.  Please have a good read of both posts alongside the information below.  It is a real eye-opener for those who might have problems with FODMAPs.

I was walking through the supermarket last week when I noticed a strategically positioned copy of The Healthy Food Guide on a stand in the vegetable section. The HFG promotes itself as ‘practical ideas from the experts‘, and is largely put together by dieticians and registered nutritionists (and promoted heavily on that basis). As such it is very much a promoter of ‘conventional wisdom’ and contains quite a high density of advertising that supports the overriding views (high carb, low fat, saturated fat is bad, etc).

What caught my eye on this particular issue was the headline on the front cover suggesting a newly discovered food intolerance could be the cause of irritable bowel-type bloating. This intolerance (though not exactly that new) is known as FODMAPwhich is an acronym for ‘Fermentable, Oligo-saccharides, Di-saccharides, Mono-saccharides And Polyols’.

FODMAPs are short-chain carbohydrates that are:

  • Osmotically active, so they drag water from the intestinal vessels into the intestinal lumen, thus causing diarrhoea
  • Easily degradable (fermentable) by intestinal bacteria, and yielding large amount of gases like hydrogen, carbon dioxide or methane, thus causing bloating

So what they elicit are large amounts of gastrointestinal distress not too disimilar to what is reported by those who claim to react to the likes of gluten or lactose in dairy. Whilst the contributors to the HFG do often write about gluten and offer gluten-free recipes, they are often quick to add that only those with diagnosed coeliac disease need to actively restrict gluten. There seems to be little more than a cursory acknowledgement that non-coeliac gluten intolerance may be a problem.

I have had a couple of dieticians point out that, all too often, gluten intolerance is erroneously blamed for an individual’s gastrointestinal distress, and that people are needlessly eliminating foods from their diet that are otherwise providing good nutritional value to them. Given my bias toward primal nutrition, I wholeheartedly disagree that the elimination of the usual gluten-containing suspects leads to a decline in the nutritional value of an individual’s diet. We are primarily talking about the elimination of grains from the diet and there is ample evidence (both looking from a Paleolithic perspective and from those not applying an evolutionary template to their research), to suggest that we gain little from keeping these foods in our diet, and indeed gain a lot with their elimination.

Previously, as a conventionally-minded nutritionist, I have felt that gluten was overdone as a diagnosis for everything. That attitude came from a position of ignorance. I knew little about it, didn’t know or recognise anyone who had a problem with it, I didn’t have any problems with it that I recognised, and because a gluten intolerance diagnosis came primarily from herbalists & naturopaths, and I was a registered nutritionist, I didn’t want any part of that ‘flakiness’. So I just rattled off all the same conventional platitudes in order to impress the people I wanted to be respected by. ‘See, I am a good nutritionist, because I say all the same things as doctors and professors in universities…’. This attitude is far from unique in the health fields… even if I did read something that didn’t fit with convention and believed it plausible, I wouldn’t have admitted it as it wasn’t worth it professionally…

Back to FODMAP’s. Some of the dieticians that believe that gluten is not to blame for all gastrointestinal distress, believe that the FODMAP reactions are probably the likely culprits. So let’s look at these culprits and apply a primal template in our analysis.
FODMAPs include:


  • Fructans– chains of fructose with one glucose molecule on the end. Only minimal amounts of fructans may be absorbed in human intestine [which, given 2.6 million years of evolution, suggests that perhaps we aren’t supposed to consume foods that are rich in these]. They may interfere with absorption of fructose, thus aggravating symptoms in fructose malabsorption. Fructans-rich foods are: wheat (white bread, pasta, pastries, cookies), onions, and artichokes; other not commonly problematic foods with fructans are asparagus, leeks, garlic, and chicory roots.
  • Galactans (like stacchyose and raffinose) are chains of fructose with one galactose molecule on the end. They act much like fructans. Main galactan-rich foods are legumes (soy, beans, chickpeas, lentils), cabbage and brussel sprouts.


  • Lactose (milk sugar). Lactose is in dairy products but it may be also found in chocolate and other sweets, beer, pre-prepared soups and sauces, and so on. Lactose is poorly absorbed in lactose intolerance and in small intestinal inflammation (Crohn’s disease, coeliac disease).


  • Fructose (fruit sugar). Fructose-rich foods are honey, dried fruits like prunes, figs, dates, or raisins, apples, pears, sweet cherries, peaches, agave syrup, watermelon, papaya. Fructose is often added to commercial foods and drinks as high fructose corn syrup (HFCS). Fructose causes symptoms (due to malabsorption) even in healthy people, if ingested in excess – which from above, seems to be caused by the presence of fructan-rich foods.

Polyols, also known as sugar alcohols (appearing as artificial sweeteners in commercial foods and drinks):

  • Sorbitol may appear in “sugar-free chewing gum”, “low calorie foods”; naturally it appears in stone fruits: peaches, apricots, plums.
  • Xylitol is also present in chewing gum and naturally apears in some berries. A pack of chewing gum containing sorbitol or xylitol may cause bloating or diarrhea in a healthy child and especially in persons with fructose malabsorption or small intestine bacterial overgrowth (SIBO).
  • Other polyols, like mannitol, isomalt, erithrytol, arabitol, erythritol, glycol, glycerol, lactitol, ribitol, (all of which rarely occur in nature, and then in minimal amounts compared to that which is added to processed foods) may be problematic in fructose malabsorption and SIBO.

I have highlighted all those foods which do not match up with a primal template – foods that would not have been available to humans to eat for the best part of their evolution to date. So if we wanted to reduce the gastrointestinal distress associated with FODMAP intolerance, we would primarily look to be eliminating;

  • Wheat
  • Dairy
  • High fructose foods
  • Artificial sweeteners

Add to this list industrial oils, and you come pretty close to the prescription for a Paleo/Primal-type diet. Indeed, those who have undertaken such a diet invariably comment on being less ‘windy’.

Some may look at the foods implicated in FODMAP intolerance however, and note that there are plenty of ‘primal’ foods that also appear to cause problems… such as some vegetables and fruits. Without doubt, there would be individuals who are incredibly sensitive to even these foods. However, it is my belief and clinical experience that many people become sensitised to these naturally occuring FODMAP sources by virtue of their exposure to the non-primal, and often richer FODMAP sources.

To put it another way, if I were to administer you with large doses of a toxin that aggravated your gastrointestinal system, then I would suspect that even small ‘natural’ doses of the same toxin would induce a reaction until such time as I had removed the main source of the problem and had given you enough time to desensitise to it.

I have had clients report that, upon undertaking a period of wheat-free eating, they become able to eat such things as fruit that had previously caused them a degree of discomfort and distress. So it would seem that there is a threshold effect, and if that were the case, I would be looking to eliminate the richest FODMAP sources in order to obtain the largest degree of symptom reduction and to bring gut sensitivity back to normal. It just so happens that following a predominantly primal diet achieves this to the highest degree, with the least hassle (not taking out these major non-primal items would involve a lot of juggling around of certain fruits, vegetables, etc, so as to avoid discomfort, e.g. not eating asparagus and cabbage in the same meal).

So if these FODMAP foods are potentially the main contributors to gastrointestinal distress, where does that leave our usual suspect – gluten? In my book, gluten is still a bad guy. Even if it isn’t generating gastrointestinal issues in non-coeliacs, it still may very well be contributing to leaky gut. Additionally, there are specialists who believe that the majority of gluten problems are in fact extra-intestinal, i.e. gluten does most of its damage beyond the gut. Indeed, Dr Rodney Ford hypothesises that gluten intolerance is a neurological problem before it is a gut problem. Here is a short video from Dr Ford on this;

Dr Rodney Ford – The Gluten Syndrome

Are gluten-free foods also FODMAP free? Not always. Some gluten-free grains still contain FODMAPs and therefore still end up eliciting gastrointestinal discomfort. This may leave an individual confused and dismayed when they do not obtain relief from going gluten-free. Years of damage to the gut lining may also leave that individual more susceptible to FODMAP intolerance. Whether FODMAP intolerance may be a trigger to the initiation of the likes of coeliac disease remains to be investigated.

Whether an individual’s gastrointestinal distress is due to gluten, dairy, or FODMAP intolerance, the most practical strategy an individual can undertake is to move toward a more primal diet. They will get everything they need, and very little of foods that they had never evolved to eat in the first place.

Conventionally based dieticians and nutritionists seem to miss the point entirely. They will continue to argue that one shouldn’t go wheat-free for the purpose of avoiding gluten (in ignorance of a body of research that suggests this would be a wise, health-promoting step) whilst promoting ‘new research’ suggesting 30-40% of people may derive some benefit from avoiding wheat in order to reduce the symptoms of FODMAP intolerance. As far as the by-line on The Healthy Food Guide of ‘practical ideas from the experts‘ the ‘experts’ would seem to be anything but practical.

At risk of turning my blog into a redirection service, given the topic covered here, I wish to direct your attention to a very excellent post from Dr Briffa on gluten and dairy being major dietary contributors to constipation (primarily written with regard to children, but applies equally to adults in my experience).

3 thoughts on “FODMAP’s

  1. malpaz

    dairy constipatesme so i have been trying to give it up. according to Dr Ayers at cooling inflammation however, regenerating gut flora and bacteria will allow someone who doesnt process dairy well to regenerate and be able to eat dairy… any opinion?i see onion, brussel sprouts and asaragus on the list…. 3 foods i really like. :( i am thinking eating primally as i do should make onions okay theyre like one of my favorite flavor enhancers to beef! im not a fruit eater and obviously not an artifical user but i dont quite understand why some primaly veggies would cause problems?

  2. Jamie Scott

    Hi MalpazWas Dr Ayers making reference to lactose within dairy? My understanding is that the caseins within dairy can be the constipating factor, whereby they act effectively act on the smooth muscle of the gut in the same way as the likes of morphine or codeine does. I'm not sure that regenerating gut flora would stop this occuring.The three vegetables you listed are fine. My suggestion is always to knock out the non-primal foods first and see how much any symptoms settle. If any of these foods do cause issues, it might be a case of just rotating the loads. E.g. you would eat onion, Brussels sprouts, and asparagus in the one meal if you had issues with all three. But separately, they might be better tolerated.

  3. julianne

    Hi Jamie,With regards to dairy and constipation – the paleo diet fixed it for me (I was born with it – seriously as a breast fed baby I pooped every 5 days!). I'm sure both dairy and gluten contribute, interestingly I had a whey isolate protein shake a few months ago and it bunged me up for a couple of days. I've had a client respond this way too.

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