Gastroenterologist disses the value of chewing

Perusing on-line newspapers yesterday I came across this. According to the national newspaper the Observer (UK), Professor Chris Hawkey, president of the British Society of Gastroenterology (BSG), is set to debunk more than a dozen ‘fad’ diets when he addresses Gastro 2009 conference for doctors. Locked in his crosshairs, apparently, are the concepts of chewing thoroughly, and the raw, grapefruit, and alkaline diet.

To be honest, when I read that a gastroenterologist was going to pronounce on the suitability of different diets, I felt uncomfortable. For two reasons really. First of all, many dietary approaches that appear to work in practice have not been subjected to systematic study. So, dismissing them on scientific grounds is not, well, very scientific. If Professor Hawkey has a stack of science that shows that such approaches definitely do not work, then I am honestly all ears. But if he hasn’t, then all he is offering is an opinion.

But the other reason I am uncomfortable about Professor Hawkey’s pronouncements is the fact that he is a gastroenterologist. And the fact is, my experience is that many doctors of this specialism appear to believe that diet has little or nothing to do with gastrointestinal disease. I see a steady stream of patients with gastrointestinal symptoms of diagnosed conditions who tell me their gastroenterologist told them, point blank, that their condition is in no way related to what they eat.

Now, many of these individuals are incredulous at this. They argue, quite rightly I think, that what and how they eat is very likely to impact on the health of the gut. Some ask rhetorically How could what I eat not be affecting my gut?

Now, not all gastroenterologists dismiss diet as a potential trigger of digestive illness. I, for example, have a friend a colleague who happens to be a gastroenterologist but, nonetheless, embraces diet quite enthusiastically when managing certain gastrointestinal diseases. However, as a general rule, my experience is that gastroenterologists tend not to be particularly open to the nutritional management of the conditions that confront them regularly.

By way of demonstration, let’s have a look at Professor Hawkey’s dismissal of the value of chewing. From the piece linked to above we learn that The chewing movement emerged in the 19th century with the claim that chewing each mouthful 32 times helped digestion. “Gladstone was apparently very eccentrically in favour of this diet,” said Hawkey of the British prime minister who died in 1898. “The idea is that salivary enzymes start digestion.” However, like many other diets, it was based more on “theory than evidence”, according to Hawkey.

Let’s have a look at that theory for a moment. As I wrote about here and here, slower eating (and more thorough chewing) appears to lead to people eating less. It does not seem so far fetched, therefore, that advising people to chew thoroughly might help them lose weight.

And even if they do not lose weight, there may be other benefits to be had from proper mastication. Professor Hawkey is right that the action of enzymes in the mouth help kick start the digestive process (amylase and lipase start the digestion of carbohydrate and fat respectively). However, the mechanical effect of chewing is also important. Thorough chewing increases the surface area of food that ends up in the stomach, and this aids digestion. Imagine dropping two ice cubes into water but crushing one first. Which one melts more quickly? The crushed one, right? It’s the same with food in the stomach.

So, one thing that thorough chewing can do is help reduce the risk of symptoms such as heartburn and indigestion. I don’t believe anyone’s ever studied it, but my experience is that it works, and generally leaves individuals feeling far more comfortable after a meal.

Writing this a memory of an event that occurred a few years ago was awoken. A fellow journalist had written about a piece about how to combat indigestion naturally and without drugs. Her advice seemed reasonable to me, and included advice to chew thoroughly. However, she had received a quite irate letter (which she forwarded to me) from a gastroenterologist claiming that her advice was simply bunkum. He also disputed her claim that changing the diet in a specified way might help provide relief from indigestion.

In his letter, the gastroenterologist in question wrote something that it stuck in my memory. He claimed What one eats has no bearing on the symptoms of indigestion. Whether we eat bananas and cream or old boots and laces, it makes no difference to the stomach. One does not need to be a gastroenterologist to understand just how jaw-droppingly ill-informed this ‘expert’ opinion is.

Anyway, we can see how Professor Hawkey’s stance on chewing flies in the face of common sense and at least a little science. I am left wondering whether Professor Hawkey’s time might be better spent not debunking supposed myths, but embracing some basic nutritional principles. Starting with advising his patients to chew their food thoroughly.

12 Responses to Gastroenterologist disses the value of chewing

  1. Marc Feel Good Eating 23 November 2009 at 10:38 pm #

    I became friends with a nice fellow here in town who is a gastroenterologist.
    Like me he’s in his 40’s, but he eats like a child. soda and sugary drinks all day, eats candy like crazy, and has the most atrocious diet you’ve ever seen. His sugar intake was so high that he messed up his teeth and recently had a lot of mouthwork done to fix it.
    He doesn’t want to hear about diet at all.
    He’s a nice guy…….but it baffles me to no end.


  2. Anna Salvesen 24 November 2009 at 1:54 am #

    I’ll bet he’d really roll his eyes at the suggestion that aroma and anticipation of a good meal jump starts digestion.

    Think about it. In modern life, we rarely have appetizing aromas wafting and permeating our senses before meals, whetting our appetites, and signaling to our body that food is on the way. You know, mouth-watering aromas. Now we microwave foods and only get a whiff during the last minutes of heating up and opening the door or we order our food and it is transported to our table or counter away from the kitchen (or worse, to our car).

    In the past, our bodies had more ample preparation for meals, as our hands might have been immersed in the food during preparation, our taste buds may have sampled already, and even those arriving or waiting for others to prepare meals, had noses awakened by roasting, simmering, or pungent aromas.

  3. Bill 24 November 2009 at 3:49 am #

    Although I understand the logic of chewing and try myself to chew more, I can’t imagine our paleolithic ancestors chewing as a “natural” way of eating.
    Steffanson, wrote in “My life with the eskimo” that his companions wolfed there food down like their dogs, when they were very hungry. Gulping it down with very little chewing.
    I do believe that what you eat is more important than how you chew it.
    Probably hunger and lack of food, which would mean enforced periods of fasting, pre-agriculture, are more important.
    Maybe fasting between meals and perhaps the occasional 36-48 hour fast would be more beneficial to the digestive and metabolic system.

  4. Nancy LC 24 November 2009 at 3:58 am #

    I do hope that author challenged the gastro to eat a boot and laces. In the name of science, of course.

  5. Chris 24 November 2009 at 4:10 pm #

    Would our digestive tract still function if it were stripped of the 500 species of bacteria that populates it and whose number exceeds the total number of our individual cells by a factor of 10 : 1 ?

    There exists a far too mechanistic appreciation of the workings of the human body which lingers from earlier times. For example, our organs are not a collection of parts such as engine, gearbox, or exhaust.
    Instead our bodies are a collection of cells that evolve diversity following the moment of conception and the distinguished cells manage to coordinate themselves into collaborative groups that divide tasks between them. They are coded to do so consequentially of positive evolutionary outcome. We exist because it works. Higher order life seems to be ‘variations on a theme of tube’. Might we deduce that the contents of the tube are important?
    Are not the patterns of collaboration and division of function repeated hierarchically in nature and within our own bodies? Do we not recognise division of function within a cell and apply the term ‘organelles’ (small organ?)? And are the patterns visible in the behaviour of colonies of species of insects?

    Personally, I think we should look after the little fellows that populate our gut like our lives depended upon them for it has the hallmarks of a symbiotic relationship. Perhaps we should put their gastronomic preference before our own. That we fail to feed them sufficient prebiotic material may be reflected in the sales of probiotics?

    The argument that we should look after the little fellows that populate healthy and fertile soil would appear to be valid for much the same reason and largely neglected for much the same reason. Colin Tudge recently blogged about the need to enter ‘The Age of Biology’. His point largely featured upon agriculture and economics. As a species we can never leave the age of biology, but human behavior and application of science has been a departure .. .. and isn’t your gastroenterologist a case in point?

    I had a pint or two of beer last night, John, was I guilty of biocide?

  6. Ted Hutchinson 24 November 2009 at 5:12 pm #

    Hawkey comments “Atkins Nutritional Approach, the famous diet that is low in carbohydrates and high in protein,”
    While it’s true reducing carbohydrate intake and eating until satisfied, inevitably leads to an increase in protein intakes, in practice it is fairer to describe Atkins as a low carb high fat diet.

    In the You Tube Video The Battle of the Diets: Is Anyone Winning (At Losing?) Christopher Gardner explains what happens in practice when people are properly educated over 8 weeks in the principles underlying the diet they were assigned to but then left to get on with that diet for the rest of the year.

    In practice those on Atkins ended up with the greatest health improvements, so the fact quoted by Hawkey that only 2% of women think Atkins is healthy, reflects only the power health professionals and the press, have in misleading people.

    Rather then spending his time making a fool of himself discussing matter he clearly doesn’t fully understand, Professor Chris Hawkey would do better spending his time explaining those aspects of modern diet and lifestyle that are directly associated with weight gain and that also increase inflammation.

    Perhaps we could persuade Hawkey to watch Sugar the Bitter Truth Robert Lustig and maybe follow that up with Taubes Dartmouth Lecture

    I wonder if Hawkey has any idea how many gastroenterological conditions are also associated with low vitamin D status and/or low omega 3 high omega 6 ratios?

  7. Susan 24 November 2009 at 11:58 pm #

    There was an excellent article in the August edition of Scientific American called “Celiac Disease Insights: Clues to Solving Autoimmunity,” which discussed how people who are unable to digest a certain protein in wheat develop leaky gut, which in turn, can lead to celiac disease or to a number of autoimmune diseases such as diabetes and arthritis. So, it’s becoming clear that what we eat not only affects our gastrointestinal health directly, there is a longer-term impact on our overall health.

    Unfortunately, physicians are more likely to suggest stress reduction or prescribe Nexus to patients complaining of stomach pain than suggest dietary modification (and even then are more likely to point as dairy as the culprit than wheat).

  8. Ted Hutchinson 25 November 2009 at 2:29 pm #

    Scientific American requires a subscription but the text of “Celiac Disease Insights: Clues to Solving Autoimmunity” can be found here

    For those new to the topic of how diet may cause autoimmune illness
    Loren Cordain has an excellent video on how MS may develop
    Celiac and MS are related and in both an increase in inflammatory signaling molecules leads to vitamin D deficiency, as well as accelerated bone loss.
    While 1000iu/daily vitamin D raises 25(0H)D 10ng 25nmol/l in healthy people 2000iu/daily D3 is required to achieve the same result in those with inflammatory conditions.
    Your body only has significant reserves of D3 when 25(OH)D is ABOVE 50ng/ml 125nmol/l.
    So while healthy people will find 5000iu/daily D3 sufficient in the UK those with autoimmune conditions may require 10,000iu/daily to keep above 55ng/ml.

  9. Lucy-Ann 28 November 2009 at 6:15 pm #

    Without needing to go into the “science” or medicine” behind digestion… why on earth have we evolved to possess teeth, if not to chew with, in order to help/assist/begin digestion?

  10. Terry 29 November 2009 at 1:05 am #

    My thanks to Ted for the celiac article from ‘Scientific American’. It’s really interesting stuff – and very recent.

  11. Mr Spoon 13 August 2011 at 5:01 pm #

    terrible article. The physiology of eating and digestion is complex and what we understand has been meticulously documented and tested. It takes effort to do scientific research where as it takes no brain cells to write tripe like this blog.
    The ‘anticipation’ of foods based on sight and aroma is a well defined part of the medical model of eating and appetite. It’s called the cephalic state of digestion and involves stimulation from the parasympathetic nerve to the pariatal cells of the stomach (along with increased salivation). Pavlov showed that salivation can also be triggered by conditioning.

    People who genuinely have coeliac disease can have a terrible time trying to avoid wheat and they get really ill and malnourished and anaemic if they eat too much wheat. that’s not to say that wheat is bad for everyone, just count yourslef luckly that you don’t have this reaction. If you have symptoms consistent with coeliacs a gastroentoroligist will test you for it with a blood test and an endoscope and biopsy (a invasive procedure). Clearly if you have stomach problems which seem to be linked to wheat but are unlikely to be coeclacis then stop eating it!

    The problem is that the gastroenterologist has hundreds of people in his/her outpatients clinic convinced that they should be avoiding all sorts of food like dairy, wheat, carbs ets mostly thanks to web sites such as this and terrible fad diets.
    The only effective treatment for coelicacs disease supported by medical evidence is gluten avoidance.

    Please don’t just dimiss gastroenteroligist, there are people who read this blog who genuinly are ill and need to be tested so that they can make informed decisions about their health.

    If you guys are genuinely interested in finding real answers then there are some terrific research articles.
    For instance did you know that one option for inducing crohn’s disease into remission is elemental feeds which contain amino acids but no large peptides. This is pretty unappetizing ‘food’ but is now recommended over steroids for many pediatrics cases of crohn’s where steroids may interfere with growth.
    Now before you jump in: chewing thoroughly in no way reduces food to single amino acids.

    Lets face it, even if a well designed study showed that chewing your food 30 times before swallowing was beneficial. I would not want to have dinner with you.

    Open your minds.

  12. John Briffa 13 August 2011 at 9:58 pm #

    Mr Spoon

    The physiology of eating and digestion is complex and what we understand has been meticulously documented and tested….
    The ‘anticipation’ of foods based on sight and aroma is a well defined part of the medical model of eating and appetite. It’s called the cephalic state of digestion and involves stimulation from the parasympathetic nerve to the pariatal cells of the stomach (along with increased salivation). Pavlov showed that salivation can also be triggered by conditioning.

    Thanks for getting your brain out for us, but what’s this got to do with chewing, and its role in digestion?

    Now before you jump in: chewing thoroughly in no way reduces food to single amino acids.

    So, what? Answer me this, which is easier for the body to digest, a whole 16-ounce porterhouse steak, or the same steak thoroughly chewed?

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