Showing posts with label Coeliac Disease. Show all posts
Showing posts with label Coeliac Disease. Show all posts

Wednesday, 28 August 2013

Things that make you go "Struth!"

I was wading through my Facebook News Feed when I spotted THIS. That article led me to New approach to coeliac testing identifies more Australians at risk, which in turn led me to A novel serogenetic approach determines the community prevalence of celiac disease and informs improved diagnostic pathways (provisional pdf), where I saw: "HLA-DQ2.5, DQ8, or DQ2.2 was present in 56% of all women and men in the community cohorts."
HLA-DQ2.5, DQ8 & DQ2.2 are the alleles for Coeliac/Celiac Disease (CD).
Image from http://www.clker.com/clipart-tango-face-surprise.html
"Transglutaminase (TG)-2 IgA and composite TG2/deamidated gliadin peptide (DGP) IgA/IgG were abnormal in 4.6% and 5.6%, respectively, of the community women and 6.9% and 6.9%, respectively, of the community men, but in the screen-positive group, only 71% and 75%, respectively, of women and 65% and 63%, respectively, of men possessed HLADQ2.5, DQ8, or DQ2.2."
There were abnormalities in ~5% of Australian women & ~7% of Australian men, even in those who didn't carry CD alleles.

"...but based on relative risk for HLA-DQ2.5, DQ8, or DQ2.2 in all TG2 IgA or TG2/DGP IgA/IgG screen-positive subjects, CD affected 1.3% or 1.9%, respectively, of females and 1.3% or 1.2%, respectively, of men."
~1.6% of Australian women & ~1.3% of Australian men have CD.

From the discussion: "The concept of a ‘celiac iceberg’ has been important in drawing attention to a large, unrecognized group of patients with CD who do report symptoms considered ‘typical’ of CD [29]. Investigators have proposed expansion of the ‘iceberg’ to encompass patients who are genetically susceptible to CD, but show only raised IEL counts or an isolated abnormal CDspecific serology and normal intestinal histology [30-32]. Consequently, there is considerable uncertainty regarding the true extent of gluten-mediated disease in the community.

Random thoughts: About 1 in 20 Australian women & about 1 in 15 Australian men have some kind of a gut problem (IBS?) due to gliadin, even in those who don't carry CD alleles. The following made me smile.
"Making a diagnosis based on a blood test alone or commencing a gluten-free diet without a confirmatory bowel biopsy is inappropriate and can impose an unnecessary and lifelong treatment."
'Cos life without wheat, rye, barley & oats is such an imposition (undue burden) and everyone just loves to be given a bowel biopsy. <- sarcasm alert.

From Ancestry of Australian population: "More than 92 percent of all Australians descend from Europeans. Anglo-Celtic Australians (English, Scottish, Welsh, Cornish or Irish ancestral origin) make up 74 percent of the Australian population."
Most Australians have genes that originate from Britain & Europe. Uh-oh!

Why do only a small percentage of people carrying the CD allele go on to develop CD? I believe that it's down to luck. During digestion, gliadins are snipped into fragments & amino acids by the peptidase enzymes pepsin, trypsin & chymotrypsin. Gliadin fragments that contain the wrong triplet of amino acids and that manage to slip through excessively-loose tight junctions may trigger CD. Once the "damage is done", it only takes a tiny amount of gliadin to provoke an immune response.

Friday, 14 June 2013

Grains & soyabeans: more bad news.

Jamie Scott (THAT PALEO GUY) has been doing some digging and found more dirt on...
From http://commons.wikimedia.org/wiki/File:Various_grains.jpg
See Wheat amylase trypsin inhibitors drive intestinal inflammation via activation of toll-like receptor 4.
"We identify the α-amylase/trypsin inhibitors (ATIs) CM3 and 0.19, pest resistance molecules in wheat, as strong activators of innate immune responses in monocytes, macrophages, and dendritic cells. ATIs engage the TLR4-MD2-CD14 complex and lead to up-regulation of maturation markers and elicit release of proinflammatory cytokines in cells from celiac and nonceliac patients and in celiac patients' biopsies. Mice deficient in TLR4 or TLR4 signaling are protected from intestinal and systemic immune responses upon oral challenge with ATIs. These findings define cereal ATIs as novel contributors to celiac disease. Moreover, ATIs may fuel inflammation and immune reactions in other intestinal and nonintestinal immune disorders."

See Impact of antinutritional factors in food proteins on the digestibility of protein and the bioavailability of amino acids and on protein quality.
"Examples of naturally occurring antinutritional factors include glucosinolates in mustard and canola protein products, trypsin inhibitors and haemagglutinins in legumes, tannins in legumes and cereals, gossypol in cottonseed protein products, and uricogenic nucleobases in yeast protein products."

"Among common food and feed protein products, soyabeans are the most concentrated source of trypsin inhibitors. The presence of high levels of dietary trypsin inhibitors from soyabeans, kidney beans or other grain legumes have been reported to cause substantial reductions in protein and amino acid digestibility (up to 50 %) and protein quality (up to 100 %) in rats and/or pigs."

"Normally encountered levels of phytates in cereals and legumes can reduce protein and amino acid digestibility by up to 10 %. D-amino acids and LAL formed during alkaline/heat treatment of lactalbumin, casein, soya protein or wheat protein are poorly digestible (less than 40 %), and their presence can reduce protein digestibility by up to 28 % in rats and pigs, and can cause a drastic reduction (100 %) in protein quality, as measured by rat growth methods. The adverse effects of antinutritional factors on protein digestibility and protein quality have been reported to be more pronounced in elderly rats (20-months old) compared to young (5-weeks old) rats, suggesting the use of old rats as a model for assessing the protein digestibility of products intended for the elderly."

I eat grains, also peas, beans & lentils, but not as a dietary staple. I make sure that they're thoroughly cooked at 100°C.

Monday, 20 May 2013

Keep 'em tight, Part 2.

Keep 'em tight was about the ramifications of excessive gut permeability, a.k.a."Leaky Gut".
Graphic From: www.leakygutcure.com
Almost as an afterthought, I added to that post a link to Physiology and Immunology of Digestion. As this article is interesting & informative and since only 706 people have read the first post since it was published (the link was added quite some time later), I thought that I'd give it another airing, with a picture to make the post more attractive.

Sunday, 31 March 2013

Doctor, every time I do *this*, it hurts!

The correct response is either:-

1) Go to hospital and get that broken finger fixed, or
2) Stop doing *that*!

There seem to be a lot of people out there who are having problems with wheat gluten (gliadin), casein and other proteins. As Matt Lalonde said in The Science Behind the Paleolithic Diet, some proteins are harder to digest than others.

Here's a hard to digest protein:-


It's raw albumin (egg white protein). As mentioned in As sure as Eggs is Eggs....., raw albumin is poorly absorbed, compared to cooked albumin. To digest the above protein requires peptidase enzymes (pepsin, trypsin and chymotrypsin) to break the peptide bonds. This has to be done from the outside inwards, so a large, heavily-folded protein takes a long time to break down into individual amino acids. Cooking albumin changes the 3-D structure - this is called denaturing. Cooked albumin digests much faster than raw albumin, which is why it's much better absorbed. Cooked proteins are generally faster to digest than raw proteins, unless they're burned to a crisp on a barbecue!

In a person with a healthy gut, partially-digested proteins are not absorbed, as the molecules are too large to pass through the tight junctions in the small intestine. They just ferment, producing malodorous wind. In a person with impaired gut permeability, partially-digested proteins pass through the loose junctions and get into the blood, provoking an immune response. This is not good, so Keep 'em tight.

People who suffer ill-effects after eating certain proteins may either have the wrong genes (e.g. coeliac disease), or have impaired gut permeability. The former isn't fixable but the latter may be. In the meantime, if eating "X" hurts, don't eat "X"!

Sunday, 19 February 2012

Oh no, not again!

Today's title is a quote from Douglas Adams' "The Hitchhiker's Guide to the Galaxy".



There seems to be a lot of hysteria & worry around the Internet.

Oh, noes! They took away her lunch-box (they didn't)! Her lunch-box! That's crap!

Oh, noes! They made her eat chicken nuggets (they didn't)! Chicken nuggets! That's crap!

Oh, noes! They made her eat a portion of grain! A portion of grain! That's crap!

Oh, noes! They wanted to give her a carton of skimmed milk! Skimmed milk! That's crap!

Oh, noes! They wanted to give her a carton of chocolate milk! Chocolate milk! That's crap!

Is there too much fat in this Guacamole?

Is there too much omega-6 in this pork?

Is there too much BPA in this bottled water?

And so on...

Firstly, chicken nuggets, grains, skimmed milk and chocolate milk are not crap. They're not perfect, but they're far better than chocolate/candy bars and fizzy drinks.

Schools act in loco parentis, so they are not going to feed the children crap. USDA guidelines are nowhere near perfect, but children who aren't humongously fat are metabolically-flexible. Therefore, whether they eat carbohydrates or fats, their bodies will burn them. If a child has been diagnosed with Coeliac disease, they won't be given gluten grains (unless the school wants to get sued).

Eat some carbs, dammit. See Why I Ditched Low Carb.

To quote from The Hitchhiker's Guide to the Galaxy again, DON'T PANIC! The dose makes the poison. Dietary fructose is used by the liver to make blood glucose to run red blood cells & the brain. A non-keto-adapted brain uses ~140g/day of glucose. Therefore, in the absence of any other dietary carbohydrates, a child could eat 100g/day of fructose, or 200g/day of sucrose without harm. Obviously, other carbohydrates are being eaten, so the amount of fructose that can be eaten without harm is probably ~50g/day, or ~100g/day of sucrose, or ~90g/day of HFCS55.

Warning, irony alert. So, light up a large spliff and chill a bit! Here's a song to help.



EDIT: Worrying about "X" may be worse for you than "X" itself, due to the adverse effect of chronically-elevated cortisol.

Tuesday, 14 February 2012

Does it really matter?

I mean, does it really matter exactly how & why low-carb diets work? My thoughts...



There's a lot of in-fighting on the internet about low-carb & paleo diets etc. Which is "best", exactly how they work and so on. I don't believe that there is a best diet. Everyone is different (in genetics, environment, activity etc). To boil it down to the basics:-

1) Eat real food that hasn't been buggered-about with too much. Grains that have had the outer husk removed (e.g. white rice) are O.K. Grains that have been rolled flat or inflated to a large size by heating to >100°C are O.K. Grains that have been ground into dust are not O.K.

2) If eating "X" causes you problems, stop eating "X". If certain proteins cause you problems, you either have a genetic condition (e.g. coeliac disease) or excessive gut permeability. The first isn't fixable but the second may be. If certain carbohydrates cause you problems, you either have a genetic problem or insulin resistance. The first isn't fixable but the second may be.

The real enemy here is the food manufacturers. They don't want people to stop eating their highly-profitable Crap-in-a-Bag/Box/Bottle (CIAB), as it's bad for business. They also influence Governments. So let's stop fighting amongst ourselves and attack the real enemy any way that we can. Lead by example.

Tuesday, 1 February 2011

Keep 'em tight.

Wheel nuts? Nope!
Image from https://suppversity.blogspot.de/2012/11/shedding-some-light-on-the-leaky-gut.html
I'm referring to Tight Junctions. As mentioned at the end of Wheat? Oh, dear! , 10% of people who are healthy enough to donate blood have gut walls permeable enough to let gliadin fragments pass into the blood.

Tight junctions are important, as they keep the contents of the gut inside the gut and out of the blood. If you read Food Combining: What's THAT all about?, you'll see that during digestion, proteins are broken down into individual amino acids & very short peptide chains*. Amino acids & very short peptide chains are small enough to pass through tight junctions. Peptide chains longer than about 3 amino acids are too big to pass through. See also Physiology and Immunology of Digestion.

Carbohydrates are broken down into monosaccharides, which are small enough to pass through. Disaccharides are too large.

Fats are broken down into glycerol and fatty acids. Glycerol is small enough to pass through. Fatty acids and other fatty molecules such as Vitamin D, Co-enzyme Q10, Vitamin K2, curcumin, berberine etc are transported across.

The consequences of having loose junctions are not good. Chains of amino acids that aren't supposed to pass through the gut wall enter the body and produce an antibody response, e.g. Beta-CasoMorphin 7 and/or Gliadorphin 7. That in itself isn't a problem, unless amino acid sequences in the chains match amino acid sequences in certain parts of the body.

Diseases of autoimmune origin such as Coeliac disease (gut), Eczema (skin), Dermatitis herpetiformis (skin), Psoriasis (skin & joints), Sjögren's syndrome (mucous membranes), Cerebellar ataxia (Purkinje cells in the brain), Multiple sclerosis (myelin sheaths of nerves), Type 1 Diabetes (pancreatic beta cells), Rheumatoid arthritis (joints), Asthma (lungs), Lupus erythematosus (various), Autoimmune thyroiditis (thyroid), LADA (pancreatic beta cells) etc are caused by antibody responses inappropriately attacking parts of the body. Autoimmune diseases can also occur after bacterial & viral infections.

The other day, I found Immune response to dietary proteins, gliadin and cerebellar peptides in children with autism.

See also Stronger Intestinal Barrier May Prevent Cancer in the Rest of the Body, New Study Suggests.

So, how do we keep 'em tight? See Vitamin D.
See also Dietary Fat Can Modulate Intestinal Tight Junction Integrity.
See also Shedding Some Light on the Leaky Gut <> Exercise Connection. Plus: 20+ Things You Should or Shouldn't Do to Protect and Restore the Integrity of Your Intestinal Wall.
See also Sulphation and Autism: What are the links? A good source of sulphate is Epsom Salts.



In other news....
I had a phone call from mum's GP this morning. Having read my evidence, he's agreed to test mum's serum B12, 25(OH)D and Calcium and give her supplements accordingly. He's also happy with me giving mum a Ketogenic diet and will also advise the nursing home to exercise mum as often as she is able. Result!

I put four cubes of liver pâté out for Sooty & Sweep (I don't know which one is which as they're identical) and a Magpie swiped two of them. We also have seagulls. I put the other two cubes out of sight in a box.


So far, so good!

P.S. What fuel can be extracted from decomposing seagulls?
.
.
.
Wait for it...
.
.
.
Petrel! (From Petrol Direct, a joke site in case anyone's wondering).

Tuesday, 6 January 2009

Gluten - more than just a pain in the guts?

Remember the advert "I'm feeling a bit bloated". "Here, have some Bifidus Digestivum!"? I wonder what percentage of the population suffers from bloating, gas pains, constipation, IBS or some degree of failure to absorb the nutrients from their food?

People with Coeliac Disease (CD) or Dermatitis Herpetiformis (DH) (intensely itchy spots on pressure points) have to avoid gluten as much as possible, as it produces an auto-immune response with antibodies that attack their own bodies. However, gluten is also implicated in other conditions due to molecular mimicry. Sjogren's syndrome (dry eyes & other bits) and cerebellar ataxia (brain damage) are mentioned in a huge article by Loren Cordain Cereal Grains: Humanity’s Double-Edged Sword.

This article suggests that there are conditions other than CD & DH which can be helped by switching from gluten-containing grains (wheat, rye, oats, barley & spelt) to non gluten-containing ones (rice, corn, quinoa, buckwheat, millet & amaranth). Luckily, supermarkets like Tesco, Waitrose and Sainsbury's now have a large "Free from" section, which makes finding gluten-free substitutes for breads, cakes, biscuits & breakfast cereals etc a lot easier.

EDIT: See also Keep 'em tight.

Wednesday, 17 December 2008

Blood Glucose, Insulin & Diabetes

Diabetes is afflicting an increasing percentage of the population as time goes by. Even athletes like Sir Steven Redgrave can get it. This article tries to explain the workings of the body's blood glucose (BG) regulation system and what can go wrong with it.


How does the body regulate blood glucose?

At any given moment, there's ~4.5g of glucose in your blood (5mmol/L x 180g x 5L). As the brain alone uses about 6g of glucose per hour in the absence of ketones, blood glucose (BG) level could fall to zero within an hour if we ate no sugary/starchy carbs. If we ate a mere 5g of glucose, BG level could double. As very low BGs are fatal and very high BGs damage proteins by a process called glycation (a bit like caramelisation), the body keeps BG levels within fairly tight limits by the use of a negative feedback (NFB) control system.


How does a negative feedback control system work?

NFB systems consist of a non-inverting (more in → more out) part, which in this case are the islet cells of Langerhans (a.k.a. pancreatic beta cells), as increasing BG level results in increasing insulin secretion. It's actually more complicated than that. Beta cells can store insulin and dump it into the blood if there is a sudden increase in BG level. This is analogous to the accelerator pump in a carburettor, which dumps petrol into the engine if you slam your foot on the accelerator pedal, i.e. it produces a rapid response. The dumping of insulin from beta cell storage is known as the 1st Phase insulin response. If this (or the accelerator pump) fails, there is a lag in the response; this will become significant below.

Increasing BG level results in increasing insulin secretion from beta cells and is known as the 2nd Phase insulin response.

The other part of a NFB system is the inverting (more in → less out) feedback part, which in this case is split into three parts, all working in parallel. They are:
  1. Liver - increasing insulin level results in decreasing Hepatic Glucose Production.
  2. Muscle cells - increasing insulin level shifts GLU-T4 transporters which shuttle glucose from the blood into cells, decreasing BG level.
  3. Fat cells - increasing insulin level shifts GLU-T4 transporters which shuttle glucose from the blood into cells, decreasing BG level.


What can go wrong?

There are three main types of diabetes:

1) Type 2 diabetes. This is by far the most common (about 95% of all cases) and is usually caused by abdominal obesity. Type 2 diabetes has two main mechanisms going on. The first is a progressive insulin resistance (IR) of target tissues, possibly caused by increased levels of saturated fatty acids being fed to the liver from abdominal fat stores, chronically-high BG and insulin levels caused by chronically over-consuming high glycaemic load carbohydrates, possibly accompanied by large amounts of saturated fat and/or large amounts of omega-6 fat. A sedentary lifestyle lowers the sensitivity of muscle cells to insulin. Insulin resistance also has a hereditary link. IR is reversible. See Insulin Resistance: Solutions to problems.

Insulin resistance weakens the feedback in the NFB system, resulting in increased BG level (hyperglycaemia) and increased insulin level (hyperinsulinaemia). See Hyperinsulinaemia and Insulin Resistance - An Engineer's Perspective. Increased BG level causes increased damage to beta cells by glycation. Increased insulin level gradually causes further insulin resistance as target tissues become increasingly insensitive (a bit like louder and louder music making you progressively deafer and deafer). Eventually, beta cells become too damaged to secrete sufficient insulin and insulin levels begin to fall. This results in a massive rise in BG level and this is now full-blown Type 2 diabetes. There are five main treatments for Type 2 diabetes:
  1. Lifestyle interventions - reduced intake of high glycaemic load carbohydrates and/or increased intake of omega-3 fats and/or increased intake of Vitamin D3 and/or increased intense exercise and/or loss of abdominal fat.
  2. Sulphonylureas - drugs which stimulate beta cells to secrete even more insulin. Unfortunately, that's a bit like flogging a dying horse as it doesn't address the problems caused by weakened feedback and eventual beta cell failure is inevitable, resulting in the need for insulin injections.
  3. Biguanide drugs such as Metformin - increase insulin sensitivity in target tissues. This strengthens the feedback in the NFB system, which results in reduced BG and insulin levels. This combined with lifestyle interventions can return the NFB system to normal operation.
  4. Thiazolidinediones - also increase insulin sensitivity in target tissues, e.g. muscle and fat, as well as possibly improving the secretory function of beta cells. Increases the number of new, empty fat cells.
  5. Insulin injections take the strain off beta cells, but may worsen insulin resistance.

2) Type 1 diabetes. This is much less common (about 5% of all diabetes cases) and is caused by an autoimmune disease. One possible mechanism is as follows: Due to an increase in Zonulin, the gut becomes more permeable than it should (a.k.a. Leaky Gut), which allows protein fragments to pass into the blood. These are locked-onto by antibodies, and destroyed by the immune system. However, if a protein fragment happens to have the same sequence of amino acids as a protein in your body, the immune system sets about destroying parts of your own body. Examples of this are gluten (proteins found in wheat, rye, barley and oats) producing antibodies in the blood that can destroy the gut causing Coeliac Disease, or skin cells causing Dermatitis Herpetiformis, or mucous membranes causing Sjogren's Syndrome, or brain cells causing Cerebellar Ataxia. As there's an association between the consumption of cows' milk and the incidence of type 1 diabetes (see here ), it's possible that, in susceptible individuals, casein protein fragments enter the blood, resulting in auto-immune destruction of pancreatic beta cells. Another possible mechanism is autoimmune attack after a viral infection. Once all beta cells have been destroyed, no insulin is secreted and insulin injections are required. If some beta cells survive, there's a possibility that normal BG levels can be maintained if sugary/starchy carbohydrate intake is reduced.

3) Latent Autoimmune Diabetes of Adulthood (LADA). This is a slow developing diabetes that is more like type 1 in origin (autoimmune with antibodies) but is often misdiagnosed as type 2 because of the age at diagnosis and the relatively slow progression of the disease (slow compared to type 1 but fast compared to type 2). It is believed that Sir Steven Redgrave has this. Whether or not his autoimmune disease was triggered by a huge intake of milk (to build those Olympic-winning muscles), we'll never know. To minimise your risk of developing autoimmune diseases, see Keep 'em tight.



What else can go wrong?

As stated earlier, loss of the 1st Phase insulin response can occur. This usually happens when beta cells are chronically over-secreting insulin due to a chronically-high intake of sugary/starchy carbs and are unable to store any. This results in a lag in insulin response. This isn't a problem if low glycaemic load carbs are eaten and BG levels change only a little or very slowly. However, if high glycaemic load carbs are eaten, this produces a rapid rise in BG level. If a NFB loop with a lag in it is presented with a step response change in input level, its output overshoots. This results in too much insulin being secreted (a.k.a. postprandial hyperinsulinaemia), which causes feelings of postprandial sleepiness and also down-regulates insulin receptors in the ventromedial hypothalamus (VMH), resulting in an eventual normal insulin level being interpreted by the VMH as rebound hypoinsulinaemia, which causes feelings of ravenous hunger (as insulin acts as a satiety/satiation hormone in the brain). The solution? Stick to low glycaemic load carbs.


Where does blood glucose come from if I haven't eaten?

When no sugary/starchy carbs are being digested, BG starts to fall. Adrenaline and noradrenaline (catecholamine hormones) are secreted by the adrenal medulla into the blood and also by sympathetic neurons. Like glucagon (see below), they stimulate the mobilisation of glycogen and triacylglycerols (stored fats) by triggering the production of cyclic AMP (adenosine mono-phosphate). Adrenaline and noradrenaline differ from glucagon in that their glucose-producing effect is greater in muscle glycogen than in liver. They also inhibit the uptake of glucose by muscle. Instead, fatty acids released from adipose tissue are used as fuel. Adrenaline also stimulates the secretion of glucagon and inhibits the secretion of insulin. Thus, catecholamines such as adrenaline and noradrenaline increase the amount of glucose released into the blood by the liver and decrease the utilization of glucose by muscle.

Pancreatic alpha cells secrete glucagon. This hormone mobilises the conversion of liver glycogen into glucose. The liver only stores about 70g of glycogen, but when combined with water, a larger mass of glucose is generated. Eventually, liver glycogen stores become depleted and BG level falls again. Glucagon also stimulates gluconeogenesis in the liver & kidneys, which is the production of glucose from non-carbohydrate precursors, like the conversion of glucogenic amino acids, such as glutamine, into glucose. This causes slow muscle wastage unless there is sufficient protein intake to provide the necessary amino acids. When BG falls to about 3.3mmol/L, the pituitary kicks-in and secretes ACTH (adrenocorticotropic hormone) which stimulates the release of cortisol from the adrenal cortex. Cortisol further stimulates gluconeogenesis in the liver & kidneys by catabolising (breaking down) muscle mass. When BG level falls to about 2mmol/L, the pituitary secretes GH (Growth Hormone) which has an anti-insulin effect.


What else does insulin do?

Insulin has many metabolic effects in the body apart from lowering BG level. It's a very anabolic hormone and an insulin spike is usually desired post workout to maximise the uptake of glucose and amino acids by muscle cells. There's nothing wrong with the occasional short-term insulin spike. It's chronically-high insulin levels due to chronic overconsumption &/or insulin resistance that cause long-term health problems like high blood pressure and clogging of arteries.